Measles Outbreak in British Columbia
As of 4/21/2010, total of 54 cases* of measles have been reported in BC since the second week of March 2010; 51 (94%) are laboratory confirmed and 3 are epidemiologically linked to laboratory confirmed cases. This is the highest number reported since the year 2000 when 42 cases were reported. From 2002 through 2009, fewer than 5 cases were reported each year, with no cases reported in 0 to 4 cases were reported annually in BC.
Cases have occurred in all regions of BC, with the majority in Vancouver Coastal and Fraser health regions, the southern parts of which are known as ‘the lower mainland’. Three First Nations communities have been affected, including one of the index clusters. They range in age from 5 months to 64 years with a mean of 22 years. About half are male. The most recent date of rash onset was April 11th. Several are linked to recognized clusters including one large household based cluster with connections to several communities outside of the lower mainland area. Four cases have become infected in hospital emergency rooms including one health care worker. 17 cases (31%) have had unknown vaccination history, 19 (35%) are unimmunized, 8 (15%) likely had one dose of MMR, 2 (4%) had documentation of one dose of MMR and 4 (7%) were 2-dose recipients.
Half of the cases attended emergency rooms, and 11 (20%) have been hospitalized. One case was seriously ill and required ventilatory support in ICU.
The outbreak is thought to have started after importation of measles to Vancouver in two separate events in late February through early March. Two distinct measles virus genotypes have been identified from early Vancouver based cases. One had onset on March 9th with genotype H1 identified and the other with onset March 17th had a D8 genotype. A separate importation occurred to the interior outbreak of BC in late February in a traveler returning from India, also a D8 genotype, but not known to be associated with subsequent transmissions.
One British Columbia resident with measles traveled to visit family members living in Seattle over the Easter weekend (April 3 & 4th) while contagious. This visit resulted in the potential for measles exposure at the Seattle Aquarium on Saturday April 3rd between 3pm and 7pm, and at a MacDonald’s on Samish Way in Bellingham between 2 and 5 pm on Sunday April 4th.
*as of 4/23/2010, the total case count is 70 cases.
Source: WA Dept of Health, 4/21/2010 and British Columbia Centre for Disease Control, 4/23/2010
Latest updates from the WA Dept of Health
British Columbia CDC Measles Outbreak Link: http://www.bccdc.ca/resourcematerials/newsandalerts/healthalerts/MeaslesMarch30.htm
Press release: Whatcom County - 4/23/2010
Press release: Whatcom County - 4/16/2010
Press release Seattle-King County
PAO IHS Guidance:
Idaho: MEASLES ALERT for Providers - ID Measles Outbreak (ID)
Oregon: MEASLES ALERT for Providers - OR Measles Outbreak (OR)
Washington: MEASLES ALERT for Providers - WA Measles Outbreak (WA)
