The Public Health Agency of Canada (PHAC) is committed to sharing information about H1N1 flu virus cases with Canadians. Confirmed cases are posted Monday, Wednesday and Friday at 4 p.m. EDT.
As of May 22 2009, a total of 805 laboratory-confirmed cases of H1N1 flu virus have been reported in 9 provinces and 1 territory in Canada (see Table 1 below).
As of May 20, 2009, half the cases are 21 years of age or younger (median: 21 years; range: %lt;1 – 86 years). To date, 21 cases have been hospitalized and one death has been reported. The most recent date of symptom onset is May 15, 2009.
The following graph, also known as an epidemic curve, is up to date as of May 20, 2009. The graph illustrates the course of the current H1N1 flu virus outbreak in Canada. It shows the date when symptoms of H1N1 flu virus began for each of the laboratory-confirmed cases.
Figure 1. Number of Laboratory-Confirmed H1N1 flu virus Cases in Canada by Date of Onset as reported to the Public Health Agency of Canada of May 20, 2009 15:00 EDT (N=539).
Source: Provincial/Territorial Ministries of Health
When interpreting the graph, it should be noted that:
- The graph is prepared retrospectively and is updated daily using the information available at that time. It is not as current as Table 1 that contains the summary of laboratory-confirmed cases, as information about the date of onset of symptoms takes more time to compile.
- There is always a delay from the date that an illness starts to the date the case is reported to public health authorities. This delay is the result of the time required for patients to see their physicians, laboratory testing to be completed, and results to be communicated to public health authorities.
