RESUMO
In December 2014, the first detection in Canada of a highly pathogenic avian influenza A (HPAI) virus was reported in poultry within the Fraser Health Authority of British Columbia. It was the second outbreak of HPAI from Eurasian H5 reassortment viruses in North America. The Fraser Health Authority provided the lead public health coordination for this response as well as consultation and support to the occupational health response. The public health response focused on contact tracing, monitoring and follow-up for household, farm worker and other community contacts exposed on the affected farms. A total of 50 contacts were identified. Contacts received daily active monitoring by public health nurses for seven days from their last exposure and were advised to self-monitor until day 10. All contacts and other household members were recommended seasonal influenza vaccination to protect against further possible reassortment with human influenza viruses circulating within the community at the time. A total of 26 (52%) contacts were recommended chemoprophylaxis for ongoing exposure to the affected barns and flocks, of whom only 11 (42%) initiated this. During the seven-day active surveillance period, four contacts developed acute respiratory symptoms and influenza B was identified in one individual. Local area health care providers and acute care facilities were alerted to the outbreak and public messaging was provided regarding the human health risks from avian influenza. Collaboration between health and agriculture at the local, regional, provincial and federal levels was key to a rapid response to this outbreak.
RESUMO
BACKGROUND: Although Canada eliminated endemic measles in 1998, outbreaks are expected to occur periodically through import-related transmission in geographically clustered unvaccinated communities. In the spring of 2014, in association with an outbreak in the Netherlands, a large measles outbreak occurred in British Columbia in a community unvaccinated for religious reasons. METHODS: Case finding with assistance of the local community, its school and religious leaders and local health care providers was conducted to identify confirmed, probable and suspect cases. Measles control guidelines were implemented with limited uptake of measles-containing vaccine (MCV) but higher adherence with infection control measures and travel restrictions. RESULTS: A total of 433 cases (325 confirmed and 108 probable) were identified. Rash onset ranged from February 22 to June 9, with 98% during March and April. Fifty-seven percent of cases were students of one school. The median age of cases was 11 years and 68% of cases were aged five to 19 years. Ninety-nine percent of cases were unvaccinated. One case had encephalitis and recovered. Only five cases occurred outside of the affected community. Genotyping results were consistent with importation from the Netherlands outbreak. CONCLUSION: This outbreak in a community with low-vaccination rates affected largely the pediatric-age population, compatible with acquisition of measles immunity by adult members due to prior wild-type measles infection. Although vaccine hesitancy persisted in this population, containment of the outbreak was facilitated by a high degree of community cooperation with infection control measures and restriction of movement.
