Canadian Notifiable Disease Surveillance System - Counts and Rates of Reported Cases of Nationally Notifiable Diseases Read-Me Guide and disease description Data Notes and Limitations AIDS was added to the notifiable disease list in 1986; data include national totals only with no age/sex breakdown. Please see the 2016 AIDS Surveillance Report. The populations of the following provinces have been removed for rate calculation in the years noted: BC did not report on AIDS in 2016; QC did not report on AIDS in 2003 through 2016; NL did not report on AIDS in 2009 through 2016; PE did not report on AIDS in 2012 through 2016. Acute flaccid paralysis was added to the notifiable disease list in 2000. Acute flaccid paralysis data were obtained from the Canadian Acute Flaccid Paralysis Surveillance system. For further information regarding this system please see the Canadian Acute Flaccid Paralysis Surveillance System. Only the under 15 population is included for surveillance of acute flaccid paralysis. Amoebiasis was added to the notifiable disease list in 1927 and removed after 1999. There was no reporting of amoebiasis by any provinces or territories in 1928 and 1929. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. From 1959 through 1968, it is possible that some amoebiasis cases were reported in the 'dysentery unspecified' category. The populations of the following provinces and territories have been removed for rate calculation: AB did not report on amoebiasis in 1927 through 1935; MB did not report on amoebiasis in 1927 through 1932; NB did not report on amoebiasis in 1927 through 1936, 1938 through 1950, and 1952 through 1955; NL did not report on amoebiasis in 1949 through 1952; NS did not report on amoebiasis in 1927 through 1931; NT did not report on amoebiasis in 1927 through 1958, and 1960 through 1962; ON did not report on amoebiasis in 1927 through 1930; PE did not report on amoebiasis in 1927 through 1951, 1969, and 1970; QC did not report on amoebiasis in 1927 through 1933, 1935 through 1938, 1943 through 1947, and 1954 through 1956; A12SK did not report on amoebiasis in 1930, and 1960 through 1963; YT did not report on amoebiasis in 1930 through 1955, and 1979. Anthrax was added to the notifiable disease list in 1930, removed after 1982, and returned in 2002. There was no reporting of anthrax by any provinces or territories in 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation: AB did not report on anthrax in 1956, 1958, 1960, and 1961; NB did not report on anthrax in 1931 through 1952; NT did not report on anthrax in 1960 through 1962, and 1924 through 1958; PE did not report on anthrax in 1931, 1956, 1958, and 1960 through 1978; QC did not report on anthrax in 1956 and 1958; YT did not report on anthrax in 1931 through 1956. Botulism was added to the notifiable disease list in 1933. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. From 2013 through 2016, QC data may include probable cases of botulism. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB did not report on botulism in 1933 through 1935, 1960, and 1961; NB did not report on botulism in 1933 through 1951; NL did not report on botulism in 1949 through 1952; NT did not report on botulism in 1933 through 1958, and 1960 through 1962; ON did not report on botulism in 1956, 1958, 1960, and 1969 through 1971; PE did not report on botulism in 1933 through 1935, 1949 through 1952, and 1961 through 1968; QC did not report on botulism in 1949 through 1952, and 1956; SK did not report on botulism in 1933 through 1952; YT did not report on botulism in 1933 through 1955, 1956, 1958, and 1960. Brucellosis was added to the notifiable disease list in 1928. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. From 2013 through 2016, QC data may include probable cases of brucellosis. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation: AB did not report on brucellosis in 1928 through 1930, 1957, 1958, and 1960; BC did not report on brucellosis in 1928; MB did not report on brucellosis in 1928 through 1930, 1932, and 1933; NB did not report on brucellosis in 1928 through 1936, 1943, 1944, 1947, 1949, 1951, 1952, 1954, and 1955; NS did not report on brucellosis in 1928 and 1929; NT did not report on brucellosis in 1928 through 1958, and 1960 through 1962; PE did not report on brucellosis in 1928 through 1935, 1949 through 1951, and 1971 through 1979; QC did not report on brucellosis in 1928 through 1932; SK did not report on brucellosis in 1928 and 1929; YT did not report on brucellosis in 1928 through 1955. Campylobacteriosis was added to the notifiable disease list in 1986. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. MB did not report on campylobacteriosis in 1988 through 1993. The population of this province has been removed for rate calculation. Chickenpox has been reported since 1924. Chickenpox was removed from the notifiable disease list after 1958 and returned in 1986. In 2011 through 2016, ON has notified the CNDSS that there is systematic under-reporting of chickenpox for their jurisdiction. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB did not report on chickenpox in 1956 through 1958; BC did not report on chickenpox in 1993 through 2016; MB did not report on chickenpox in 1988 through 2016; NB did not report on chickenpox in 1956 through 1958; NL did not report on chickenpox in 1957, 1958, and 2016; NS did not report on chickenpox in 1998 through 2016; NT did not report on chickenpox in 1924 through 1958; PE did not report on chickenpox in 1924 through 1929, 1957, and 1958; ON did not report on chickenpox in 1991, 1992, 2009, and 2010; QC did not report on chickenpox in 1988 through 2016; SK did not report on chickenpox in 1957, 1996, 1997, and 2001 through 2016; YT did not report on chickenpox in 1924 through 1955, 1958, and 2009 through 2012. Chlamydia was added to the notifiable disease list in 1991. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. NB did not report on chlamydia in 1991. The population of this province has been removed for rate calculation. Cholera was added to the notifiable disease list in 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following province and territories have been removed for rate calculation: NT did not report on cholera in 1930 through 1958, and 1960 through 1962; PE did not report on cholera in 1930 through 1956, 1958, and 1960 through 1978; YT did not report on cholera in 1930 through 1956. Clostridium difficile associated diarrhea was added to the notifiable disease list in 2009. For Clostridium difficile associated diarrhea NL reported national totals only with no age or sex breakdown for 2013 through 2016; these data are not included here. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB and NS did not report on Clostridium difficile associated diarrhea in 2009 through 2011; BC, NU, ON, QC, and SK did not report on Clostridium difficile associated diarrhea in 2009 through 2016; NB did not report on Clostridium difficile associated diarrhea in 2009 through 2014; PE did not report on Clostridium difficile associated diarrhea in 2009 and 2010; NL and YT did not report on Clostridium difficile associated diarrhea in 2009 through 2012. Congenital rubella syndrome was added to the notifiable disease list in 1979. Congenital rubella syndrome data include national totals only, with no age/sex breakdown. The denominators for rate calculations are live births. Prior to 1979, it is possible that some congenital rubella syndrome cases were reported in the 'rubella' category. From 2013 through 2016, QC data may include probable cases of congenital rubella syndrome. NU data for 2015 are preliminary and subject to change. Creutzfeldt-Jakob disease was added to the notifiable disease list in 2000. Creutzfeldt-Jakob disease data are available here. Please see the CJD Surveillance System reports. Cryptosporidiosis was added to the notifiable disease list in 2000. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. From 2013 through 2016, QC data may include probable cases of cryptosporidiosis. QC did not report on cryptosporidiosis in 2000 through 2003. The population of this province has been removed for rate calculation. Cyclosporiasis was added to the notifiable disease list in 2000. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. From 2013 through 2016, QC data may include probable cases of cyclosporiasis. The populations of the following provinces have been removed for rate calculation in the years noted: NB did not report on cyclosporiasis in 2000 through 2014; PE did not report on cyclosporiasis in 2000 through 2012; QC did not report on cyclosporiasis in 2000 through 2003. Diphtheria has been reported since 1924. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following province and territories have been removed for rate calculation in the years noted: PE did not report on diphtheria in 1924 through 1928; NT did not report on diphtheria in 1924 through 1958, and 1960 through 1962; YT did not report on diphtheria in 1924 through 1955. Dysentery - type unspecified was added to the notifiable disease list in 1959 and removed after 1968.From 1959 through 1968, it is possible that some amoebiasis cases were reported in the 'dysentery unspecified' category. The populations of the following provinces and territories have been removed for rate calculation in the years noted: NT did not report on dysentery - type unspecified in 1960 through 1962; ON and YT did not report on dysentery - type unspecified in 1960; PE did not report on dysentery - type unspecified in 1960 through 1963;SK did not report on dysentery - type unspecified in 1960 through 1967. Food poisoning includes staphylococcus and other unspecified bacteria, but not salmonella, which is reported separately. Food poisoning was added to the notifiable disease list in 1959 and removed after 1981. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB and YT did not report on food poisoning in 1960. NT did not report on food poisoning in 1960 through 1962; ON did not report on food poisoning in 1960 through 1967, and 1971 through 1977. Giardiasis was added to the notifiable disease list in 1983. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. MB did not report on giardiasis in 1990 through 1996. The population of this province has been removed for rate calculation. Gonorrhea has been reported since 1924. There was no reporting of gonorrhea by any provinces or territories in 1925 and 1926. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB, NB, PE, and SK did not report on gonorrhea in 1924 through 1930; BC did not report on gonorrhea in 1924 through 1938; MB did not report on gonorrhea in 1924 through 1937; NS did not report on gonorrhea in 1924 through 1926; NT did not report on gonorrhea in 1924 through 1958; QC did not report on gonorrhea in 1924 through 1943; YT did not report on gonorrhea in 1924 through 1955. Invasive group A streptococcal disease was added to the notifiable disease list in 2000. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. From 2013 through 2016, QC data may include probable cases of invasive group A streptococcal disease. NU data for 2015 are preliminary and subject to change. Group B streptococcal disease of the newborn was added to the notifiable disease list in 2000. Group B streptococcal disease of the newborn data include national totals only, with no age/sex breakdown. The denominators for rate calculations are live births. NU data for 2015 are preliminary and subject to change. The populations of the following provinces have been removed for rate calculation in the years noted: AB did not report on group B streptococcal disease of the newborn in 2000 through 2010; MB did not report on group B streptococcal disease of the newborn in 2000 through 2014; QC did not report on group B streptococcal disease of the newborn in 2000 through 2016. Invasive Haemophilus influenzae, non-b disease was added to the notifiable disease list in 2007. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territory have been removed for rate calculation for the years noted: AB did not report on invasive Haemophilus influenzae, non-b disease in 2007 through 2011; BC did not report on invasive Haemophilus influenzae, non-b disease in 2007 through 2010; NB, NS, NT and ON did not report on invasive Haemophilus influenzae, non-b disease in 2007 through 2016; PE did not report on invasive Haemophilus influenzae, non-b disease in 2007 through 2012. Invasive Haemophilus influenzae, type b disease was added to the notifiable disease list in 1986. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. NB did not report on invasive Haemophilus influenzae, type b disease in 2007 through 2016. The population of this province has been removed for rate calculation. Hantavirus pulmonary syndrome was added to the notifiable disease list in 2000. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces have been removed for rate calculation in the years noted: PE did not report on hantavirus pulmonary syndrome in 2000 through 2012; NB did not report on hantavirus pulmonary syndrome in 2000 through 2014. Hepatitis A was added to the notifiable disease list in 1927, removed after 1958, and returned in 1969. Between 1959 and 1968, hepatitis A and hepatitis B were reported as a combined category. For ease of understanding over time, data for this period have been excluded. From 2013 through 2016, QC data A35may include probable cases of hepatitis A. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July.In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation in the years noted: AB did not report on hepatitis A in 1927 through 1946, 1948, 1956, and 1957; BC did not report on hepatitis A in 1927 through 1938, and 1940 through 1944; MB did not report on hepatitis A in 1927 through 1951; NB did not report on hepatitis A in 1927 through 1952; NL did not report on hepatitis A in 1949; NS did not report on hepatitis A in 1927 through 1936, 1940, 1941, 1947, and 1956; NT did not report on hepatitis A in 1927 through 1958; PE did not report on hepatitis A in 1927 through 1953; QC did not report on hepatitis A in 1927 through 1951, and 1956; SK did not report on hepatitis A in 1927 through 1930; YT did not report on hepatitis A in 1927, and 1929 through 1955. Hepatitis B reporting does not differentiate between acute and chronic cases. Hepatitis B was added to the notifiable disease list as a separate disease in 1969. BC reported only acute cases of hepatitis B in 2005 and 2006, and began including hepatitis B chronic cases from 2007. ON reported only acute cases of hepatitis B in 2009 and 2010, and began including hepatitis B chronic cases from 2011. SK reported only acute cases of hepatitis B in 2007 and 2008, and began including hepatitis B chronic cases from 2009. YT began including hepatitis B chronic cases from 2008. From 2013 through 2016, QC data may include probable cases of hepatitis B acute cases. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces have been removed for rate calculation in the years noted: ON did not report on hepatitis B in 1969 and 1970; PE did not report on hepatitis B in 1969 through 1978. Hepatitis C was added to the notifiable disease list in 1991. Hepatitis C reporting does not differentiate between acute and chronic/unresolved cases. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces have been removed for rate calculation in the years noted: MB did not report on hepatitis C in 1991 through 1998; NB, NL, and NT did not report on hepatitis C in 1991 and 1992; NS and QC did not report on hepatitis C in 1991 through 1995; YT did not report on hepatitis C in 1991 through 1993. Hepatitis, non-A, non-B has been included in the blood borne and sexually transmitted disease grouping but could also include forms of hepatitis that are transmitted by other means. Hepatitis, non-A, non-B was added to the notifiable disease list in 1983, removed after 1989, returned in 1991, and removed again after 1999. Hepatitis, unspecified has been included in the blood borne and sexually transmitted disease grouping but could also include forms of hepatitis that are transmitted by other means. Hepatitis, unspecified was added to the notifiable disease list in 1959 and removed after 1968. NT did not report on hepatitis, unspecified in 1960 through 1962. The population of this territory has been removed for rate calculation. HIV infection was added to the notifiable disease list in 2000; data include national totals only, with no age/sex breakdown. Please see the 2016 HIV Surveillance Report. Influenza, epidemic has been reported since 1924 and removed after 1958. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on influenza, epidemic in 1924, 1925, 1927, 1929, 1930, 1949 through 1951, and 1955 through 1958; BC did not report on influenza, epidemic in 1926; NB did not report on influenza, epidemic in 1956 through 1958; NL did not report on influenza, epidemic in 1949, 1950, 1954, and 1956 through 1958; NT did not report on influenza, epidemic in 1924 through 1958; PE did not report on influenza, epidemic in in 1924 through 1928; QC did not report on influenza, epidemic in in 1958; SK did not report on influenza, epidemic in 1958; YT did not report on influenza, epidemic in 1924 through 1955, and 1958. Influenza data include national totals only, with no age/sex breakdown. Data for influenza are seasonal (August to August). Influenza, laboratory confirmed was added to the notifiable disease list in 2000. Influenza data for 2005 through 2016 are available here: here. Legionellosis was added to the notifiable disease list in 1986. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. Leprosy was added to the notifiable disease list in 1925. There was no reporting of leprosy by any provinces or territories in 1929. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on leprosy in 1925 through 1930, and 1961; BC did not report on leprosy in 1926 through 1930; MB and NB did not report on leprosy in 1925 through 1930; NS did not report on leprosy in 1925 through 1931; NT did not report on leprosy in 1925 through 1958, and 1960 through 1962; ON did not report on leprosy in 1925 through 1930; PE did not report on leprosy in 1925 through 1935, 1949 through 1952, 1956, 1958, and 1960 through 1978; QC did not report on leprosy in 1925 through 1929; SK did not report on leprosy in 1925, 1927, 1928, 1929 and 1979; YT did not report on leprosy in 1925 through 1956. Listeriosis was added to the notifiable disease list in 1990, removed after 1999, and returned in 2007. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on listeriosis in 1992 through 1997;NS did not report on listeriosis in 1992 through 1998; NT did not report on listeriosis in 2007 through 2011; QC did not report on listeriosis in 1992 through 1999. Lyme disease was added to the notifiable disease list in 2009. The CNDSS data on Lyme disease reflect a relatively static count of confirmed cases. For more frequently updated information, please see here. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. Malaria was added to the notifiable disease list in 1929. Malaria was removed from the notifiable disease list after 1978 and returned in 1983. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. From 2013 through 2016, QC data may include probable cases of malaria. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on malaria in 1929 through 1935, 1956, 1958, 1960, and 1961; MB did not report on malaria in 1929 through 1944, and 1948; NB did not report on malaria in 1929 through 1948, and 1950 through 1952; NL did not report on malaria in 1949 through 1951; NS did not report on malaria in 1929 through 1931; NT did not report on malaria in 1929 through 1958, and 1960 through 1962; ON did not report on malaria in 1930 and 1960; PE did not report on malaria in 1930 through 1934, 1949 through 1951, 1956, 1958, and 1960 through 1978; QC did not report on malaria in 1929 through 1948, and 1956; SK did not report on malaria in 1929 and 1930; YT did not report on malaria in 1929 through 1956. Measles has been reported since 1924, removed after 1958, and returned in 1969. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territory have been removed for rate calculation for the years noted: BC did not report on measles in 1969 and 1970; NB did not report on measles in 1956 through 1958, 1969, and 1970; NT did not report on measles in 1924 through 1958; PE did not report on measles in 1924 through 1928, 1957, 1958, 1969 through 1971, 1973 through 1978, 1987, and 1988; SK did not report on measles in 1957 and 1958; YT did not report on measles in 1924 through 1955. Meningitis, other bacterial was added to the notifiable disease list in 1979 and removed after 1999. Meningitis, pneumococcal was added to the notifiable disease list in 1979 and removed after 1999. Starting in 2000, pneumococcal meningitis was reported under invasive pneumococcal disease which is a broader category and would include other invasive pneumococcal infections. Meningitis, viral was added to the notifiable disease list in 1959 and removed after 1999. The populations of the following provinces and territory have been removed for rate calculation for the years noted: AB and SK did not report on meningitis, viral in 1961; NT did not report on meningitis, viral in 1960 through 1962; ON did not report on meningitis, viral in 1960 through 1974; PE did not report on meningitis, viral in 1961 through 1965, 1969, and 1970. Invasive meningococcal disease has been reported since 1924. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July.In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on invasive meningococcal disease in 1957; NT did not report on invasive meningococcal disease in 1924 through 1958, and 1960 through 1962; ON did not report on invasive meningococcal disease in 1962 and 1963; PE did not report on invasive meningococcal disease in 1924 through 1930, 1962, and 1963; YT did not report on invasive meningococcal disease in 1924 through 1955. Mumps has been reported since 1924. Mumps was removed from the notifiable disease list after 1958 and returned in 1986. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB and NB did not report on mumps in 1956 through 1958; NL did not report on mumps in 1957 and 1958; NT did not report on mumps in 1924 through 1958; PE did not report on mumps in 1924 through 1929, 1957, and 1958; QC did not report on mumps in 1924 through 1927; SK did not report on mumps in 1957 and 1958; YT did not report on mumps in 1924 through 1955, and 1958. Norovirus infection was added to the notifiable disease list in 2007. For norovirus some provinces and territories report only on aggregated outbreak related data; these data are not included here.NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on norovirus infection in 2007 through 2011; BC did not report on norovirus infection in 2007 through 2015; MB, NB, NS, NT, ON, QC, and SK did not report on norovirus infection in 2007 through 2016; PE did not report on norovirus infection in 2007 through 2015. Paralytic shellfish poisoning was added to the notifiable disease list in 2007. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB, MB, NT, and SK did not report on paralytic shellfish poisoning in 2007 through 2016; NB did not report on paralytic shellfish poisoning in 2007 through 2014; NU did not report on paralytic shellfish poisoning in 2007 through 2011; ON did not report on paralytic shellfish poisoning in 2007 through 2013; PE did not report on paralytic shellfish poisoning in 2007 through 2012; QC did not report on paralytic shellfish poisoning in 2013 through 2016. Paratyphoid has been reported since 1924. Paratyphoid was removed from the notifiable disease list after 1952, returned in 1969, and removed again after 1999. Paratyphoid was included in the reporting of salmonellosis starting in 2000. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on paratyphoid in 1924 through 1928, and 1930; BC and QC did not report on paratyphoid in 1924 through 1929; MB did not report on paratyphoid in 1924 through 1931, and 1935; NB and PE did not report on paratyphoid in 1924 through 1930; NT did not report on paratyphoid in 1924 through 1952; ON did not report on paratyphoid in 1924 through 1926; SK did not report on paratyphoid in 1927 and 1928; YT did not report on paratyphoid in 1924 through 1952. Pertussis has been reported since 1924. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. From 2013 through 2016, QC data may include probable cases of pertussis. The populations of the following province and territories have been removed for rate calculation for the years noted: NT did not report on pertussis in 1924 through 1958, and 1960 through 1962; PE did not report on pertussis in 1924 through 1928; YT did not report on pertussis in 1924 through 1955. Plague was added to the notifiable disease list in 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following province and territories have been removed for rate calculation for the years noted: NT did not report on plague in 1930 through 1958, and 1960 through 1962; PE did not report on plague in 1956, 1958, 1963 through 1978, and 1960 through 1962; YT did not report on plague in 1930 through 1956. Invasive pneumococcal disease was added to the notifiable disease list in 2000. Reporting of invasive pneumococcal disease includes pneumococcal meningitis which is a broader category and would include other invasive pneumococcal infections. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. From 2013 through 2016, QC data may include probable cases of invasive pneumococcal disease. ON did not report on invasive pneumococcal disease in 2000. The population of this province has been removed for rate calculation. Poliomyelitis has been reported since 1924. The WHO region of the Americas, which includes Canada, was certified polio-free in 1994. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on poliomyelitis in 1925; NT did not report on poliomyelitis in 1924 through 1958, and 1960 through 1962; ON did not report on poliomyelitis in 1924; PE did not report on poliomyelitis in 1924 through 1928; YT did not report on poliomyelitis in 1924 through 1955. Rabies was added to the notifiable disease list in 1927. There was no reporting of rabies by any provinces or territories in 1929 and 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. From 2013 through 2016, QC data may include probable cases of rabies. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB, BC, MB, NB, and SK did not report on rabies in 1927 and 1928; NL did not report on rabies in 1949 through 1952; NS did not report on rabies in 1927 through 1931; NT did not report on rabies in 1927 through 1958, and 1960 through 1962; ON did not report on rabies in 1960; PE did not report on rabies in 1927, 1928, 1956, 1958, and 1960 through 1978; QC did not report on rabies in 1927, 1928, and 1956; YT did not report on rabies in 1927 through 1956. Rubella has been reported since 1924. Rubella was removed from the notifiable disease list after 1958 and returned in 1969. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: BC did not report on rubella in 1969 and 1970; MB did not report on rubella in 1924 through 1930; NB did not report on rubella in 1924 through 1931, 1933 through 1941, 1943, 1945 through 1949, 1951, and 1956 through 1958; NS did not report on rubella in 1958; NT did not report on rubella in 1924 through 1958; PE did not report on rubella in 1924 through 1935, 1954 through 1958, and 1969 through 1978; QC did not report on rubella in 1924 through 1927; SK did not report on rubella in 1957 and 1958; YT did not report on rubella in 1924 through 1955, and 1958. Salmonellosis was added to the notifiable disease list in 1959. Salmonellosis reporting included paratyphoid starting in 2000. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: NT did not report on salmonellosis in 1960 through 1962; ON did not report on salmonellosis in 1960 through 1966; PE did not report on salmonellosis in 1960 through 1963, and 1967; YT did not report on salmonellosis in 1960. Scarlet fever and streptococcal sore throat has been reported since 1924. Scarlet fever and streptococcal sore throat was removed from the notifiable disease list after 1978. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. The populations of the following provinces and territories have been removed for rate calculation for the years noted: NT did not report on scarlet fever and streptococcal sore throat in 1924 through 1958, and 1960 through 1962; PE did not report on scarlet fever and streptococcal sore throat in 1924 through 1928; YT did not report on scarlet fever and streptococcal sore throat in 1924 through 1955. SARS was added to the notifiable disease list in 2004, after the 2003-2004 outbreak was over. There was no reporting of SARS by any provinces or territories in 2004. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted : AB did not report on SARS in 2012 through 2016; BC did not report on SARS in 2009 through 2016; MB did not report on SARS in in 2015 and 2016; NB did not report on SARS in 2012 through 2014; SK did not report on SARS in 2013 through 2016. Shigellosis has been reported since 1924. There was no reporting of shigellosis by any provinces or territories in 1925, 1927 and 1929. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on shigellosis in 1924 through 1935; BC did not report on shigellosis in 1924 through 1929; MB did not report on shigellosis in 1924 through 1941; NB did not report on shigellosis in 1924 through 1954; NL did not report on shigellosis in 1949 and 1950; NS did not report on shigellosis in 1924 through 1931; NT did not report on shigellosis in 1924 through 1958, and 1960 through 1962; ON did not report on shigellosis in 1924 through 1930; PE did not report on shigellosis in 1924 through 1951; QC did not report on shigellosis in 1924 through 1933, and 1935 through 1938; SK did not report on shigellosis in 1930; YT did not report on shigellosis in 1924 through 1955. Smallpox has been reported since 1924. Smallpox was removed from the notifiable disease list after 1981 and returned in 2002. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: NS did not report on smallpox in 1925 and 1926; NT did not report on smallpox in 1924 through 1958, and 1960 through 1962; PE did not report on smallpox in 1924 through 1930, 1957, 1958, and 1961 through 1978; YT did not report on smallpox in 1924 through 1955. Syphilis has been reported since 1924. There was no reporting of syphilis by any provinces or territories in 1925 and 1926. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. BC included only infectious syphilis cases when reporting in 1998 through 2016. SK included only infectious syphilis cases when reporting in 2005 through 2011 and 2016. Syphilis reporting does not differentiate between various categories of syphilis, with the exception of congenital syphilis, which is reported separately. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB, NB, PE, and SK did not report on syphilis in 1924 through 1930; BC did not report on syphilis in 1924 through 1938; MB did not report on syphilis in 1924 through 1937; NS did not report on syphilis in 1924; NT did not report on syphilis in 1924 through 1958; QC did not report on syphilis in 1924 through 1943; YT did not report on syphilis in 1924 through 1955. Congenital syphilis was added to the notifiable disease list in 1993. Congenital syphilis data include national totals only, with no age/sex breakdown. The denominators for rate calculations of congenital syphilis are live births. Prior to 1993, it is possible that some congenital syphilis cases were reported in the 'syphilis' category. From 2013 through 2016, QC data may include probable cases of congenital syphilis. NU data for 2015 are preliminary and subject to change. Tetanus was added to the notifiable disease list in 1957. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on tetanus in 1957 and 1958; NT did not report on tetanus in 1957, 1958, and 1960 through 1962; PE did not report on tetanus in 1957, 1958, 1961 through 1970, and 1979; YT did not report on tetanus in 1957. Trichinosis was added to the notifiable disease list in 1929 and removed after 1999. There was no reporting of trichinosis by any provinces or territories in 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on trichinosis in 1929 through 1935, 1954 through 1958, 1960, and 1961; BC and SK did not report on trichinosis in 1929; MB did not report on trichinosis in 1929 through 1952; NB did not report on trichinosis in 1929 through 1955; NL did not report on trichinosis in 1949 through 1952; NS did not report on trichinosis in 1931; NT did not report on trichinosis in 1929 through 1958, and 1960 through 1962; PE did not report on trichinosis in 1929 through 1935, 1949 through 1958, 1960 through 1970, and 1972 through 1978; QC did not report on trichinosis in 1929 through 1939, 1941 through 1948, 1955, and 1956; YT did not report on trichinosis in 1929 through 1957. Tuberculosis has been reported since 1924. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2013 through 2015, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. The populations of the following province and territories have been removed for rate calculation for the years noted: NT did not report on tuberculosis in 1924 through 1958, and 1960 through 1962; PE did not report on tuberculosis in 1924 through 1928, and 1970; YT did not report on tuberculosis in 1924 through 1955. Tularemia was added to the notifiable disease list in 1930, removed after 1982, and returned in 2002. There was no reporting of trichinosis by any provinces or territories in 1930. From 2013 through 2016, QC data may include probable cases of tularemia. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: AB did not report on tularemia in 1931 through 1933, 1935, 1954 through 1956, and 1958; BC did not report on tularemia in 1931 through 1935; MB did not report on tularemia in 1931 through 1933; NB did not report on tularemia in 1931 through 1955; NS and YT did not report on tularemia in 1931 through 1956; NT did not report on tularemia in 1931 through 1958, and 1960 through 1962; PE did not report on tularemia in 1931 through 1956, 1958, and 1960 through 1979; QC did not report on tularemia in 1931 through 1948, and 1954 through 1956. Typhoid has been reported since 1924. Typhoid was removed from the notifiable disease list after 1952 and returned in 1969. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following province and territories have been removed for rate calculation for the years noted: NT did not report on typhoid in 1924 through 1952; PE did not report on typhoid in 1924 through 1928; YT did not report on typhoid in 1924 through 1952. Typhoid and paratyphoid was added to the notifiable disease list in 1953 and removed after 1968. The populations of the following territories have been removed for rate calculation for the years noted: NT did not report on typhoid and paratyphoid in 1953 through 1958, and 1960 through 1962; YT did not report on typhoid and paratyphoid in 1953 through 1955. Verotoxigenic Escherichia coli infection was added to the notifiable disease list in 1991. From 2013 through 2016, QC data may include probable cases of verotoxigenic Escherichia coli infection. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territory have been removed for rate calculation for the years noted: BC, NS, and YT did not report on verotoxigenic Escherichia coli infection in 1991; NB did not report on verotoxigenic Escherichia coli in 1991 and 1992. Viral haemorrhagic fever was added to the notifiable disease list in 1979, removed after 1982, and returned in 2002. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. West Nile virus infection (WNV) was added to the notifiable disease list in 2003. West Nile virus data include both probable and confirmed cases, with national totals only. For more information please see: WNV surveillance reports. Yellow fever was added to the notifiable disease list in 1930. NL joined confederation in 1949, and is included from 1949 onward. Reporting to the Notifiable Disease System began in July. From 2013 through 2016, QC data may include probable cases of yellow fever. In 2014, SK reported age for cases in a format that could not be incorporated in these data at this time, thus cases are included in the "unspecified" age category. NU data for 2015 are preliminary and subject to change. The populations of the following provinces and territories have been removed for rate calculation for the years noted: NT did not report on yellow fever in 1930 through 1958, and 1960 through 1962; ON did not report on yellow fever in 1960; PE did not report on yellow fever in 1930, 1956, 1958, and 1960 through 1978; QC did not report on yellow fever in 1956; YT did not report on yellow fever in 1930 through 1956. Disease Descriptions Acquired Immune Deficiency Syndrome Acquired Immune Deficiency Syndrome (AIDS) is a serious, life-threatening condition representing the late clinical stage of human immunodeficiency virus (HIV) infection. HIV causes damage to a personÆs immune system, which causes them to become very susceptible to particular infections, conditions and cancers (collectively known as AIDS-indicative diseases). Highly active antiretroviral therapy (HAART) for HIV treatment has greatly prevented or delayed the onset of AIDS for many people infected with HIV. Acute Flaccid Paralysis Acute Flaccid Paralysis (AFP) is a potential outcome of poliovirus infection that involves the acute onset of paralysis in one or more limbs as a result of the destruction of nerve cells that activate muscles. Other causes of AFP include Guillain-BarrÚ Syndrome and various other acute neurological conditions. The surveillance of AFP is the strategy recommended by the World Health Organization (WHO) to monitor for polio in countries such as Canada where polio has been eliminated. Amoebiasis Amoebiasis (amoebic dysentery) is an intestinal infection caused by parasite called Entamoeba histolytica. Transmission occurs by eating food that is contaminated, from an infected person or drinking water containing amoebic cysts. Infection is common under conditions of crowding, in circumstances where hygiene practices are poor and among men who have sex with men. Anthrax Anthrax is an infection caused by the bacterium Bacillus anthracis. The bacteria form spores that can live in the soil for many years. Anthrax usually occurs in farm animals such as cows and sheep. It is uncommon in humans. Humans can become infected through the skin, stomach or lungs. Symptoms vary depending on the route of infection with the most serious symptoms resulting from lung infection. Prevention includes appropriate carcass disposal and vaccination. Botulism Botulism is a rare but serious illness caused by a toxin that affects the nervous system and can cause paralysis. The bacterium Clostridium botulinum, which is found commonly in nature, produces this toxin. There are four forms of botulism: foodborne, wound, infant and colonization. Some sources of foodborne botulism in Canada have included improperly home-canned low acid foods, improperly stored low acid fruit juices and fermented marine mammal meat and fish. Brucellosis Brucellosis is an infectious disease caused by the bacteria of the genus Brucella. These bacteria are primarily passed among animals, and they cause disease in many different vertebrates. Various Brucella species affect sheep, goats, cattle, deer, elk, pigs, dogs, and several other animals. It is usually transmitted through unpasteurized dairy products or contact with contaminated tissues. Campylobacteriosis Campylobacteriosis is an acute gastrointestinal illness caused by the bacteria called Campylobacter. A person becomes infected by eating contaminated food, or drinking contaminated water or raw milk. Infection may also be contracted from close contact with another infected person or animal. The illness is characterized by diarrhea, abdominal pain, malaise, fever, nausea and vomiting. Chickenpox Varicella, also known as Chickenpox, is a very common and highly infectious childhood disease that is found worldwide. Symptoms appear 10 to 21 days after infection and last about 2 weeks. The defining symptom is a characteristic blister-like rash, which can cause severe irritation. Most children have a relatively mild illness, but severe illness may occur in adults and people with depressed immunity because of existing illness or because of a treatment that they are receiving (e.g. chemotherapy). The National Advisory Committee on Immunization (NACI) recommends immunization against varicella. Chlamydia Chlamydia is a sexually transmitted infection caused by Chlamydia trachomatis. Females are more likely to be affected by the complications of untreated chlamydia infection, which include chronic inflammation of the reproductive organs and infertility. Untreated chlamydia in pregnant women can be transmitted to their infants during childbirth, which may result in eye or lung infections in the newborn. Genital chlamydial infection may increase the risk of contracting or transmitting HIV. Most people infected with chlamydia have no symptoms, which highlights the importance of regular testing and prompt treatment for sexually active people. However, the infection can be treated with an appropriate antibiotic. Cholera Cholera is an acute enteric disease caused by the bacteria, Vibrio cholerae. Classic cholera is characterized by sudden onset of painless profuse watery diarrhea, often referred to as 'rice water stool'. If untreated , cholera can progress to rapid dehydration, circulatory collapse, renal failure and death.The infection is acquired by eating food or drinking water contaminated by the stool or vomit of an infected person. Clostridium difficile Associated Diarrhea Clostridium difficile, commonly called C. difficile, is a bacterium that causes diarrhea and other serious intestinal conditions. It is the most frequent cause of infectious diarrhea in hospitals and long-term care facilities in Canada. C. difficile causes disease by releasing toxins that destroy the lining of the bowel which, in turn, causes bloating and frequent, watery diarrhea. Other symptoms such as severe abdominal pain and tenderness, and/or fever may occur. C. difficile infections are also the most common cause of pseudomembranous colitis (or inflammation of the colon). In rare instances, C.difficile can progress to more severe, life-threatening disease such as perforation of the bowel or toxic megacolon. Congenital Rubella Syndrome Congenital rubella infection occurs when the rubella virus passes from an infected pregnant mother to her baby. Infection during early pregnancy frequently results in physical and mental disabilities in the baby, a condition known as congenital rubella syndrome (CRS). CRS can be prevented by vaccinating against rubella. Creutzfeldt-Jakob Disease Creutzfeldt-Jakob disease (CJD) is a rare, fatal, infectious neurodegenerative condition known as a prion disease. The infectious agent of these diseases (a prion) is an abnormal form (PrPSc) of a normal cellular protein (PrPC). Classic CJD occurs in three forms: sporadic, genetic and infectious. Sporadic and genetic CJD together account for 95-99% of the 1-2 cases of classic CJD that occur annually in human populations. Infectious transmission of classic CJD has occurred through use of medical equipment or therapeutic products (dura mater, human growth hormone). Another, recently discovered infectious human prion disease called variant CJD (vCJD) has been linked with exposure to bovine spongiform encephalopathy (BSE), a prion disease of cattle. In a small number of cases, vCJD has also been transmitted by blood transfusion. Diagnosis of CJD can be difficult, as its clinical appearance can vary and can overlap with that of other, more common neurodegenerative diseases such as AlzheimerÆs disease. For this reason, neuropathological examination remains the diagnostic gold standard. There is currently no treatment for CJD. Cryptosporidiosis Cryptosporidiosis is an intestinal infection caused by parasites of the genus Cryptosporidium. While this parasite can be transmitted in several different ways, water is a common method of transmission. Persons at increased risk of infection include close personal contacts of infected individuals (households, family, health care and day care workers); animal handlers (e.g. cattle or sheep); persons who have ingested contaminated recreational (e.g. lake, river, pool, or hot tub) or drinking water, and travelers to disease endemic areas. Outbreaks have been reported in day care settings, among recreational water users and in municipalities with contaminated drinking water supplies. Cyclosporiasis Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis. Persons living or traveling in tropical or subtropical regions may be at increased risk because cyclosporiasis is endemic in some developing countries. Symptoms include watery diarrhea, loss of appetite, weight loss, abdominal bloating and cramping, increased gas, nausea, fatigue and low-grade fever. Foodborne outbreaks of cyclosporiasis in Canada and the United States have been linked to various types of imported fresh produce. Diphtheria Diphtheria is disease that affects primarily the upper respiratory system and is caused by the bacterium Corynebacterium diphtheriae. The bacterium is most commonly spread through person-to-person contact. Diphtheria can be prevented by vaccine. Symptoms of diphtheria include the development of a thick gray membrane in the nose, mouth and/or throat. This membrane can spread down the airways if not treated. The National Advisory Committee on Immunization (NACI) recommends immunization against diphtheria. Dysentery - Type Unspecified When the specific type of dysentery, either amoebic or bacillary, is not available, provinces and territories had the option of reporting cases as 'unspecified'. Food Poisoning Food poisoning is a broad term used to describe illness suspected to be transmitted by food. The illness could have been caused by a bacteria, virus or food-borne intoxication. Giardiasis Giardiasis is an intestinal infection caused by the parasite Giardia. While Giardia can be transmitted in several different ways, water is a common method of transmission. Person-to-person transmission is common where personal hygiene may be poor. Community outbreaks may occur by ingesting cysts from fecally contaminated food or water. Clinical illness is characterized by chronic diarrhea, abdominal cramps, bloating, weight loss and fatigue. Giardia infection is usually asymptomatic and self-limited in healthy people; however, persons with HIV infection and those who are immuno-compromised may have more severe and prolonged illness. Gonorrhea Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae. Rates of gonorrhea are higher in males, but females are more likely to experience serious complications such as chronic inflammation of the reproductive organs, infertility, or spread of infection throughout the body. While many infections may be asymptomatic, even ôsilentö infections may result in severe complications, and infants born to infected mothers may develop eye or blood infections. Genital gonorrhea infection may increase the risk of contracting or transmitting HIV. Many people infected with gonorrhea have no symptoms, which highlights the importance of regular testing and prompt treatment for sexually active people. Gonorrhea is treatable with an appropriate antibiotic; however, resistance to several antibiotic drug classes has been increasing, with fewer treatment options currently available. Group A Streptococcal Disease, Invasive Invasive Group A Streptococcus (iGAS) is caused by Streptococcus pyogenes. The bacterium is transmitted through direct contact with or inhalation of the discharges or droplets from an infected person's nose or mouth. Infection can also occur from direct contact with discharges from infected wounds. Most infections with this bacterium cause illnesses that are not life threatening such as strep throat or impetigo. Invasive disease is a severe form of infection that occurs when the bacterium gets into parts of the body where bacteria are not usually found, such as the bloodstream. This can result in serious conditions such as septicemia, meningitis or necrotizing faciitis. Group B Streptococcal Disease of the Newborn Group B Streptococcal Disease of the Newborn (GBS) is diagnosed in infants less than one month of age. Streptococcus agalactiae is a gram-positive streptococcus characterized by the presence of Group B Lancefield antigen, and can cause serious illness and sometimes death, especially in newborn infants, although many people carry Group B strep and are not aware as they are not symptomatic. GBS bacteria live in the intestines, the urinary and genital tracts. Pregnant women can pass it on to their baby during labor and childbirth. In order to prevent Group B strep infection in the newborn, pregnant women are given a GBS screening test at 35-37 weeks, and provided treatment if positive. There is no vaccine for GBS. Haemophilus influenzae Disease, non-b, Invasive Invasive H. influenzae disease is a bacterial infection causing severe illness in children. It is transmitted by direct contact, oral contact or contact with contaminated objects. There are six distinct types of H. influenzae bacteria and other nontypeable ones. H. influenzae serotype b (Hib) was the most common cause of bacterial meningitis in young children in Canada before the introduction of vaccine in 1985. In recent years most Invasive H. influenzae disease are caused by serotypes other than b. At the present time there is no vaccine available for prevention of invasive H. influenzae non-b disease. Haemophilus influenzae Disease, type b, Invasive Invasive H. influenzae disease is a bacterial infection causing severe illness in children. It is transmitted by direct contact, oral contact or contact with contaminated objects. There are six distinct types of H. influenzae bacteria and other nontypeable ones. H. influenzae serotype b (Hib) was the most common cause of bacterial meningitis in young children in Canada before the introduction of vaccine in 1985. The National Advisory Committee on Immunization (NACI) recommends immunization against Hib. Hantavirus Pulmonary Syndrome Hantavirus Pulmonary Syndrome is a severe respiratory infection caused by one of the Hantaviruses. It is spread through the inhalation of aerosolized excrement of deer mice. Hepatitis A Hepatitis A is an infection of the liver caused by the hepatitis A virus (HAV). The virus is spread when something is put in the mouth that has been contaminated with feces containing the virus. In Canada, HAV may occur in household and sexual contacts of infected people, in travellers returning from countries where HAV is common and in communities with inadequate sanitation. Symptoms of HAV infection include fever, loss of appetite, nausea, stomach pain, dark urine and a yellowing of the skin and eyes (jaundice). Unlike Hepatitis B and C, none of those infected permanently carries the virus. HAV is preventable through immunization. Hepatitis B Hepatitis B (HBV) is an infection of the liver caused by the hepatitis B virus. The virus can be transmitted through blood or bodily fluids, unprotected sexual intercourse, use of needles or other sharp objects that have been in contact with infected blood or mucosal membranes, as well as from mother to child during pregnancy and labour. HBV is endemic in some parts of the world and is considered a major occupational hazard for healthcare staff. Infected individuals may experience loss of appetite, nausea and vomiting, stomach pain, fatigue and yellowing of the skin and mucosal membranes (jaundice). Some individuals who become chronically infected with HBV may develop cirrhosis (scarring) of the liver, liver failure or liver cancer. Getting tested is important as HBV can be treated and is preventable through immunization. Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The virus is transmissible through blood or bodily fluids, tissues, contaminated needles and other sharp objects that have been in contact with infected blood or mucosal membranes, as well as from mother to child during pregnancy and labour. While asymptomatic in the majority of individuals, HCV infection may cause loss of appetite, nausea and vomiting, stomach pain, extreme fatigue and a yellowing of the skin and eyes (jaundice). About 85% of people infected with HCV may develop chronic infection, which, if left untreated, may progress to liver cirrhosis (scarring) , liver cancer or liver failure. Getting tested is important as the majority of HCV infections in Canada can be treated. Hepatitis, non-A, non-B Hepatitis non-A non-B was the term used for other forms of viral hepatitis before the Hepatitis C virus, and other forms of hepatitis, were identified. Hepatitis, Unspecified When the information on the specific type of hepatitis is not available, provinces and territories have the option of reporting 'unspecified'. Human Immunodeficiency Virus Infection The human immunodeficiency virus (HIV) causes damage to the immune system, resulting in AIDS if left untreated. HIV can be transmitted through sexual contact, sharing needles, receiving blood or blood products, or from an HIV-infected mother to her child (throughout pregnancy, during vaginal birth or through breast feeding). HIV is a life-long infection, but the virus can be controlled by taking a combination of drugs known as highly active antiretroviral therapy (HAART). Influenza, Epidemic Influenza, or the flu, is a respiratory infection caused by the influenza virus. Strains circulate every year, making people sick. Influenza typically starts with a headache, chills and cough, followed rapidly by fever, loss of appetite, muscle aches and fatigue, running nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhea may also occur, especially in children. Most people will recover from influenza within a week or ten days, but some - including those over 65 and adults and children with some chronic conditions, such as diabetes and/or cancer etc - are at greater risk of more severe complications, such as pneumonia. Influenza has been collected under two descriptions in the notifiable disease system: influenza, epidemic from 1924-1959, and influenza, laboratory confirmed from 2000 onwards Influenza, Laboratory Confirmed Influenza, or the flu, is a respiratory infection caused by the influenza virus. Strains circulate every year, making people sick. Influenza typically starts with a headache, chills and cough, followed rapidly by fever, loss of appetite, muscle aches and fatigue, running nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhea may also occur, especially in children. Most people will recover from influenza within a week or ten days, but some - including those over 65 and adults and children with some chronic conditions, such as diabetes and/or cancer etc - are at greater risk of more severe complications, such as pneumonia. Influenza has been collected under two descriptions in the notifiable disease system: influenza, epidemic from 1924-1959, and influenza, laboratory confirmed from 2000 onwards Legionellosis Legionellosis is a respiratory disease caused by the bacterium Legionella. The infection is acquired by inhaling airborne water droplets contaminated with the bacteria. Legionellosis includes two distinct illnesses: Legionnaires' disease and Pontiac Fever. Both illnesses present with loss of appetite, sore muscles, headache and fever. Legionnaires' disease involves the progression of infection to pneumonia while Pontiac Fever is the self limited form of infection with no progression to more serious illness such as pneumonia. Leprosy Leprosy, also called Hansen's disease, is a chronic disease of the skin, peripheral nerves and the mucosa of the upper airway (the nose and throat) caused by the bacterium Mycobacterium leprae. Leprosy has afflicted mankind since ancient times, carrying with it a legacy of mutilation, rejection and exclusion from society. It is estimated that there are 1-2 million people worldwide who have leprosy and who require care by the community in which they live. Leprosy is rare in Canada. Listeriosis Invasive listeriosis is a rare but serious disease caused by the bacteria Listeria monocytogenes. Listeria monocytogenes (commonly called Listeria) is a type of bacteria often found in food and elsewhere in nature. Pregnant women, the elderly and individuals with weakened immune systems are at higher risk than others. The disease can cause meningoencephalitis (an infection of the brain and its surrounding tissues) and/or septicemia (blood poisoning), either of which can result in death. Pregnant women typically experience only a mild, flu-like illness. However, infections during pregnancy can lead to a miscarriage, stillbirth, premature birth or the birth of an acutely-ill child. Some foods are more likely to carry Listeria than others. Those that present a higher risk include raw or contaminated milk, soft cheeses and ready-to-eat meats such as hot dogs, pÔtÚ and deli meats. Lyme Disease Lyme disease is caused by a bacterium called Borrelia burgdorferi that infects wild animals (mostly rodents and birds) and is transmitted by ticks, which are small spider-like blood feeding parasites that are active from spring through to autumn in some locations in Canada. People can become infected if they live, work or take leisure activities in the woodlands where the ticks live, because the ticks will feed on people as well as animals. Lyme disease is increasing in Canada as the ticks are spreading into southeastern and south central Canada. Risk from Lyme disease also occurs in southern British Columbia. There is no vaccine for Lyme disease but it can be prevented by taking simple precautions. Malaria Malaria is an acute, relapsing or chronic infection caused by one of the four malaria (Plasmodium) parasites. The severity depends on which species of the parasite is responsible for the disease. Of the four species (Plasmodium falciparum, P. vivax, P. ovale and P. malariae), falciparum is the most lethal. Severe falciparum infection can cause cerebral malaria with seizures, coma, kidney failure and death. Mixed infections can occur. Measles Measles is a highly infectious disease caused by the measles virus and is characterized by a red, blotchy rash that begins on the face. It is spread through direct contact with or inhalation of the secretions from an infected person's nose or mouth. Measles affects all age groups and can be prevented by a vaccine. The National Advisory Committee on Immunization (NACI) recommends immunization against measles. Meningitis, Other Bacterial Meningitis is an infection of the three membranes (called meninges) covering the brain and the spinal column. For the notifiable disease category "Meningitis, Other Bacteria", meningitis is caused by bacteria such as Staphylococci, Group B streptococci and enteric bacteria. The definition excludes pneumococcal meningitis (Streptococcus pneumoniae), meningococcal disease (Neisseria meningitidis), Haemophilus influenzae type B infection (Hib) and listeriosis (Listeria monocytogenes). Newborns (whose immune systems are not fully developed) and elderly people, whose immune systems do not fight infections as well as they did, are vulnerable to infection. People with head injury are also susceptible to infection. Meningitis, Pneumococcal Pneumococcal meningitis is an infection of the three membranes (called meninges) covering the brain and spinal column by the bacterium Streptococcus pneumoniae. Cases occur in infants, the elderly and certain high-risk groups. Meningitis, Viral Viral meningitis is an infection of the three membranes (called meninges) covering the brain and the spinal column by several viruses, including enteroviruses, coxsackievirus group A, coxsackievirus group B, echoviruses, arboviruses, herpes simplex viruses, measles and adenoviruses. Meningococcal Disease, Invasive Invasive meningococcal disease is an acute and serious illness caused by the bacterium Neisseria meningitidis. Invasive disease may lead to meningitis, in which the bacteria infect the fluids and membranes (called meninges) covering the brain and the spinal column, or septicemia. The National Advisory Committee on Immunization (NACI) recommends immunization against meningococcal disease. Mumps Mumps is an acute infectious disease caused by the mumps virus (paramyxovirus). It is characterized by swelling of the salivary glands under the jaw and in the cheeks. It is spread by direct contact with or inhalation of the secretions from an infected person's nose or mouth. The National Advisory Committee on Immunization (NACI) recommends immunization against mumps. Norovirus Infection Noroviruses are a group of viruses that cause gastroenteritis, an illness that usually includes diarrhea and/or vomiting. Noroviruses are commonly found throughout North America and are very infectious. Norovirus outbreaks can occur throughout the year but are more common in winter and affect all age groups. Noroviruses are transmitted either by consumption of contaminated food or water, by direct person-to-person spread or contact with contaminated objects. Paralytic Shellfish Poisoning Paralytic Shellfish Poisoning (PSP) is a rare but serious illness caused by eating shellfish that contain high levels of marine biotoxins. Symptoms begin anywhere from a few minutes to 10 hours after eating the contaminated shellfish. Symptoms are generally mild, and begin with numbness or tingling of the face, arms, and legs, followed by headache, dizziness, nausea, and muscular incoordination. In cases of severe poisoning, muscle paralysis and respiratory failure occur, and can be fatal. Paratyphoid Paratyphoid is a gastrointestinal illness caused by the bacteria, Salmonella paratyphi. The clinical picture is similar to, but milder than, typhoid fever. Paratyphoid occurs less frequently than typhoid fever. Paratyphoid is common in the developing world, and most cases in Canada are acquired during travel in endemic areas. The disease is most commonly transmitted by food and water contaminated with the feces of infected persons. Pertussis Pertussis (whooping cough) is a highly contagious infection of the respiratory tract caused by the bacterium Bordetella pertussis. It is easily transmitted from one person to another through the discharges or droplets from an infected person's nose or mouth. The illness is characterized by severe coughing spasms, which may or may not be associated with the classic inspiratory whoop made when breathing in (hence the popular name "whooping cough"). Pertussis can be prevented by a vaccine. The National Advisory Committee on Immunization (NACI) recommends immunization against pertussis Plague The plague is an infectious disease caused by a bacterium called Yersinia pestis that can affect both animals and humans. At the present time, it is extremely rare for humans to contract plague. The plague is transmitted between animals and humans by the bite of infected fleas, direct contact with infected rodents, inhalation and rarely, ingestion of infective materials. Symptoms begin with flu-like complaints like fever, chills, muscle pain, weakness and headache, and can include nausea, vomiting, diarrhea and abdominal pain. Effective treatment methods enable almost all plague patients to be cured if diagnosed in time. Several antibiotics can effectively treat plague. Pneumococcal Disease, Invasive Invasive pneumococcal disease is an acute and serious illness caused by the bacterium Streptococcus pneumoniae. Invasive disease may lead to several syndromes including bacteremia, meningitis, and/or bacterial pneumonia. The National Advisory Committee on Immunization (NACI) recommends routine use of pneumococcal vaccine for all infants as part of the routine immunization schedule. Poliomyelitis Poliomyelitis (polio) is caused by a virus that enters the body through the mouth mainly by fecal-oral contamination. Polio infections are more common in children less than five years of age; however, any person who is not immune to poliovirus, regardless of age, can become infected. Polio is most often recognized by the sudden onset of muscle paralysis but the majority of infected persons do not look or feel sick. There is no cure for polio but it can be prevented through immunization. Rabies Rabies is a serious infection of the brain and spinal cord that is caused by a virus. It is primarily a disease of animals, but can be transmitted to humans by way of a bite or a scratch from an infected animal. Without medical intervention death occurs in over 50% of cases.Treatment of rabies includes rabies immune globulin and/or vaccine, as indicated. Rubella Rubella is an infectious disease that results in a transient erythematous rash, lymphadenopathy, arthralgia and low-grade fever. Although a mild illness in most people, in a pregnant woman, the virus can cause a miscarriage or cause infection in the fetus that can result in fetal malformations. The disease is easily preventable with vaccination. The National Advisory Committee on Immunization (NACI) recommends immunization against rubella. Salmonellosis Salmonellosis is an acute gastrointestinal illness caused by bacteria belonging to the family of Salmonella. Symptoms include fever, abdominal cramps, vomiting and diarrhea about 6-72 hours after eating contaminated food or beverages. Outbreak investigations have implicated foods such as meat, poultry, uncooked or lightly cooked eggs and egg products, unpasteurized milk and dairy products and raw fruits and vegetables. Scarlet Fever and Streptococcal Sore Throat Scarlet fever, also called ôscarlatinaö, is caused by Group A streptococcus (group A strep), a bacterium commonly found in the throat and on the skin. These bacteria also cause strep throat. Scarlet fever often appears as a rash and is accompanied by a high fever and a strawberry-like appearance of the tongue. The illness is most common among children aged 5 to 18 years, but adults can also become infected. Severe Acute Respiratory Syndrome Severe Acute Respiratory Syndrome, or SARS, is a respiratory infection caused by the SARS coronavirus. People affected by SARS develop a fever, followed by respiratory symptoms, such as a cough, shortness of breath or difficulty breathing. In some cases, the symptoms become increasingly severe, and patients may require oxygen support and mechanical help to breathe. Other symptoms of SARS may include muscle aches, headaches, sore throat and diarrhea. Shigellosis Shigellosis is an acute gastrointestinal illness caused by a group of bacteria called Shigella. The illness is characterized by diarrhea accompanied by fever, nausea, vomiting, and cramps. The infection is spread by the fecal-oral route. Infection then passes either by person-to-person contact or indirectly by contaminated food or water. Outbreaks have occurred under conditions of crowding, in circumstances where hygiene practices are poor and among men who have sex with men. Smallpox Smallpox is caused by variola virus, a member of the orthopox virus genus, which also includes cowpox (vaccinia) and monkeypox viruses. Variola virus can only infect humans and has no animal reservoir. It is transmitted from person-to-person, mainly through respiratory droplets. It can also be transmitted through aerosols and contact with clothing or bedding. Cases are most infectious during the first week of illness, but the period of infectiousness extends from the development of fever (when the first bucco-pharyngeal lesions appear) until all skin lesions have scabbed over. There have been no naturally acquired cases of smallpox since 1977. In 1980, the World Health Organization confirmed the global eradication of smallpox. On 26 October, 2001, the WHO reaffirmed its recommendation against immunization of the general population. National Advisory Committee on Immunization (NACI) also believes that there is currently no evidence to support routine smallpox immunization of the general Canadian population. Syphilis Syphilis is a sexually transmitted infection caused by Treponema pallidum. If left untreated, the infection progresses through primary, secondary, latent and tertiary stages. Untreated syphilis can result in serious complications causing damage to the central nervous system, cardiovascular system, eyes, skin and other internal organs, sometimes causing death. Syphilis infection may increase the risk of contracting or transmitting HIV. Syphilis in pregnant women can be transmitted to their infants, which may result in serious or fatal complications. Individuals co-infected with syphilis and HIV require special considerations for the treatment and management of both infections. Syphilis, Congenital Congenital Syphilis is caused by the vertical transmission of Treponema pallidum from an infected mother to her fetus. The majority of infants with congenital syphilis are infected in utero, but they can also be infected by contact with an active genital lesion at the time of delivery. Syphilis can result in serious complications in pregnancy, such as spontaneous abortion, stillbirth or perinatal death. Live-born infected children can suffer serious consequences, usually within the first three months of life. Consequences include cerebral palsy, hydrocephalus, sensor neural hearing loss and musculoskeletal deformity, all of which may be prevented with timely treatment during pregnancy. However, some manifestations develop much later. Only early congenital syphilis cases (diagnosed in infants less than two years of age) are currently reported nationally. Tetanus Tetanus is a vaccine preventable disease caused by a bacterial spore which can be found in the intestines of animals and in the soil. It is an often fatal disease which affects all age groups. A person infected with the tetanus bacterium experiences painful muscle contractions that begin in the neck (hence the popular name "lockjaw") and then continue down to involve the muscles of the torso. The National Advisory Committee on Immunization (NACI) recommends immunization against tetanus. Trichinosis Trichinosis is a gastrointestinal illness caused by the intestinal roundworm, Trichinella spiralis. Persons become infected with Trichinella by eating raw or undercooked meat, especially pork, pork products and "beef products", such as hamburger, which may be mixed with pork. Trichinosis is prevented by cooking all pork and pork products at a temperature and for a sufficient amount of time to allow all parts to reach 71? C. Tuberculosis Tuberculosis, or TB, is an infectious disease caused by bacteria belonging to the Mycobacterium tuberculosis complex. Most people who become infected with the TB bacilli will never develop active TB disease. In 5 to 10 percent of people infected with TB bacilli and who have a normal functioning immune system, however, the TB bacillus will start to grow and replicate, leading to active TB disease. For people with weakened immune systems, the risk of developing TB disease is much higher. TB bacteria can attack any part of the body such as the kidney, spine, and brain, but in the majority of cases TB bacteria attack the lungs; this is known as pulmonary TB. Tularemia Tularemia is a bacterial disease that can affect animals and is found in wild animals in North America. Wild animals most often affected include rodents, rabbits, muskrats and beavers. Tularemia can be spread from animals to humans, although this is not known to occur commonly. Tularemia can be successfully treated with antibiotics. Tularemia is usually transmitted by contact with infected animals or their cages/immediate environment. Tularemia is not known to spread from person to person. Symptoms of tularemia may include ulcers on the skin or mouth, swollen glands and painful lymph glands, sudden fever, chills, headache, diarrhea, muscle aches, dry cough, sore throat, progressive weakness, joint pain, and swollen and painful eyes. Typhoid Typhoid is a serious illness caused by the bacteria called Salmonella typhi. Typhoid fever is common in the developing world, and most cases in Canada are acquired during travel in endemic areas. The disease is most commonly transmitted by food and water contaminated with the feces of infected persons. Important vehicles of spread include shellfish that have been harvested from sewage-contaminated water, raw vegetables and milk and milk products that have been contaminated by infected cattle or by the hands of an infected person. Typhoid and Paratyphoid Typhoid and paratyphoid are gastrointestinal illnesses caused by two different species of the Salmonella bacteria. Typhoid fever is more common and more serious than paratyphoid. Most cases of both of the diseases are acquired during travel to endemic areas. The diseases are most commonly transmitted by food and water contaminated with the feces of infected persons. Verotoxigenic Escherichia coli Infection Verotoxigenic (VTEC) Escherichia coli infection is an acute gastrointestinal illness caused by verotoxin producing E.coli bacteria. Escherichia coli O157:H7 is the most common cause of both outbreaks and sporadic cases, however both E.coli O157 and non-O157 VTEC are nationally notifiable. Clinical illness is characterized by diarrhea (often bloody), abdominal cramps (fever is often absent) and can be complicated by hemolytic uremic syndrome (HUS) in children under five years old. VTEC infections are generally caused by eating contaminated food, drinking contaminated water, or coming into direct contact with someone who is sick or with animals that carry the bacteria. Food-borne infections can be caused by improperly cooked beef, raw fruits and uncooked vegetables, including sprouts; unpasteurized (raw) milk and (raw) milk products, including raw milk cheese and unpasteurized apple juice/cider. Viral Haemorrhagic Fever Viral Haemorrhagic Fevers (VHFs) are a group of diseases caused by viruses. A VHF is a highly infectious, and often fatal, disease caused by one of the several different viruses. Ebola, Marburg, Lassa, Rift Valley Fever and Crimean-Congo are all different types of viruses that can cause viral haemorrhagic fevers in animals and humans. Symptoms include the sudden onset of fever, malaise, headache, sore throat, abdominal pain, vomiting, diarrhea and haemorrhaging. These are followed by collapse, shock associated with multi-organ failure and bleeding. For most VHFs there is no specific cure or vaccine. Treatment options include hospitalization, aggressive supportive care in an intensive care unit, strict isolation to prevent spread of infection, maintenance of fluid levels and electrolytes. For some patients, antiviral medication has been used. Infections and outbreaks occur sporadically in many developing areas of the world. West Nile Virus Infection West Nile virus belongs to a family of viruses called ôflaviviridaeö that can infect humans, birds, horses and mosquitoes. West Nile virus is closely related to the viruses that cause dengue fever, yellow fever and St. Louis encephalitis. The evidence shows that most people infected with West Nile virus got it from the bite of an infected mosquito. While persons of any age or health status can be at risk of developing serious health effects from West Nile virus, the overall risk of serious health effects increases with age. People with weaker immune systems are also considered to be at greater risk for serious health effects. West Nile Virus is usually acquired in an outdoor setting during mosquito season which in Canada can be from Mid-April to October. Yellow Fever Yellow fever is a zoonotic hemorrhagic fever caused by a flavivirus transmitted by Aedes aegypti mosquitoes. Yellow Fever evolves though a spectrum of three periods of illness, from fever with headache, weakness, nausea and vomiting, through a brief period of remission, to a hemorrhagic fever with vomiting blood, jaundice, generalized bleeding, shock and multi-organ failure. A very effective vaccine that induces long-lasting (10 years) immunity is commonly available.