- In week 2, influenza activity levels decreased slightly from the previous week with fewer regions reporting widespread activity. Many regions continue to report localized and sporadic influenza activity.
- Several indicators (number of laboratory detections, outbreaks and hospitalizations, and the ILI consultation rate) declined from the previous week, indicating that peak of the influenza season in Canada may have passed.
- RSV is the second most frequently detected virus after influenza and since week 38 detections of RSV have been higher than in the previous season.
- A(H3N2) continues to be the most common type of influenza affecting Canadians. In both laboratory detections, hospitalizations and deaths, the majority of cases have been among seniors ≥65 years of age.
- To date, the NML has found that the majority of A(H3N2) influenza specimens are not optimally matched to the vaccine strain. This may result in reduced vaccine effectiveness against the A(H3N2) virus. However, the vaccine can still provide some protection against A(H3N2) influenza illness and can offer protection against other influenza strains such as A(H1N1) and B. Data from the NML suggests that the circulating A(H1N1) and B strains are a good match for this year’s vaccine and will continue to provide protection for the rest of the flu season.
Are you a primary health care practitioner (General Practitioner, Nurse Practitioner or Registered Nurse) interested in becoming a FluWatch sentinel for the 2014-15 influenza season? Contact us at FluWatch@phac-aspc.gc.ca
FluWatch is Canada's national surveillance system that monitors the spread of flu and flu-like illnesses on an on-going basis. FluWatch reports, posted every Friday, contain specific information for health professionals on flu viruses circulating in Canada.
The FluWatch program consists of a network of labs, hospitals, doctor's offices and provincial and territorial ministries of health. Program objectives include to:
- Detect flu outbreaks across the country as early as possible
- Provide timely up-to-date information on flu activity in Canada and abroad to health professionals [and interested Canadians]
- Monitor circulating strains of the flu virus (like H1N1) and assess their sensitivity to antiviral medications, [such as Tamiflu and Relenza]. Antivirals, when used by doctors to treat flu, can help reduce the severity of the illness and the recovery time for a patient
- Provide information that the World Health Organization can use to make its recommendations on the best vaccine to use for seasonal flu shots.
The Summary Box above covers the main findings from the current week's FluWatch report.