Measles outbreak in Québec
Epidemiological portrait
March 26, 2009
Measles in 2007
As of April 18, 2008, the MADO (notifiable diseases) file showed 99 cases of measles for the year 2007, of which 94 were associated with a provincial outbreak lasting between April 19 and October 1 of that year. For comparison purposes, from 2003 to 2006, the annual number of measles cases varied between 0 (2005) and 3 (2004). No case had yet been reported in Québec in 2008 (period ending April 12, 2008, week 15).
Epidemiological portrait of the 2007 outbreak
A total of 94 cases of measles – either confirmed by laboratory tests (53 %) or with an epidemiological link with a confirmed case (47 %) – were reported to the Bureau de surveillance et de vigie (BSV) of the Ministère de la Santé et des Services sociaux. The first case (or index case) occurred in the Montérégie region on April 19 and the last reported case was in Montréal on October 1, 2007.
Seven regions of Québec were affected. Estrie and Montérégie were the regions that recorded the highest numbers of cases, with 32 and 38 cases respectively, amounting to 64% of total reported cases during the outbreak.
As the epidemic curve shows, numbers of cases began to build up at the end of May through mid-July. Three-quarters of cases (72%) occurred during these seven weeks (from May 27 to July 14). From mid-July, there were between 0 and 3 cases per week until the last reported case (week of September 30).
Distribution of numbers of confirmed cases of measles by week based on start of skin rash
Province of Québec – Period from April 19 to October 6, 2007 (94 cases)
Source: BSV, MSSS based on information taken from surveys conducted by the Montérégie, Montréal, Laurentides, Lanaudière, Estrie, Mauricie-Centre-du-Québec and Bas-Saint-Laurent DSPs (regional public health directorates).
Updated: March 23, 2009
| Socio-health region | Confirmed |
Total |
||
|---|---|---|---|---|
| Laboratory | Clinical + EL | Nomber | % |
|
| Estrie | 6 | 26 | 32 | 34 |
| Montérégie | 19 | 9 | 28 | 30 |
| Mauricie et Centre-du-Québec | 8 | 0 | 8 | 9 |
| Laurentides | 3 | 0 | 3 | 3 |
| Montréal | 10 | 6 | 16 | 17 |
| Lanaudière | 2 | 2 | 4 | 4 |
| Bas-Saint-Laurent | 2 | 1 | 3 | 3 |
| Province of Québec | 50 | 44 | 94 | 100 |
EL = Epidemiological link
Source: BSV, MSSS BSV, MSSS based on information taken from surveys conducted by the Montérégie, Montréal, Laurentides, Lanaudière, Estrie, Mauricie-Centre-du-Québec and Bas-Saint-Laurent DSPs (regional public health directorates).
Updated: March 23, 2009
The age of cases varied between 7 months and 46 years. Close to two-thirds (64%) were children aged between 5 and 14, the average age being 13.6. The great majority of cases (94%, or 88 cases) were deemed non-immunized. Eleven persons were hospitalized, among whom were six children aged between 1 and 14 and five adults aged between 22 and 40. All recovered well. A single region reported a case in a health worker. However, the person concerned did not visit his workplace during the contagious period.
Bureau de surveillance et de vigie
Ministère de la Santé et des Services sociaux
