Increased influenza activity in Sudbury & District Health Unit area

Advisory Alert

January 7, 2015

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Dear Colleagues:

Re: Increased Influenza Activity in Sudbury & District Health Unit Area

The Sudbury & District Health Unit is advising of increasing influenza activity in its catchment area which includes the City of Greater Sudbury and the districts of Sudbury and Manitoulin. This notice of influenza activity level serves as a signal to health care partners to enact policies and strategies to prepare for and control the further spread of influenza.

Currently, the influenza activity level is localized which means that there is sporadically occurring influenza like illness (ILI) and lab-confirmed influenza together with at least one ongoing laboratory-confirmed influenza outbreak in an institution.1 Local surveillance of influenza indicates that there has been an increased number of visits to local hospital emergency departments for fever/ILI symptoms (averaging approximately 7 visits per day) and respiratory syndromes (averaging 40 visits per day) over the past two to three weeks. In addition, there are currently 4 ongoing confirmed influenza A outbreaks occurring in local long-term care facilities.

According to FluWatch, Canada’s national influenza surveillance system, influenza A (H3N2) is the most common type of influenza currently affecting Canadians. In both laboratory detections and hospitalizations the majority of cases have been among seniors 65 years of age or older. The majority of H3N2 influenza specimens are not optimally matched to the vaccine strain which may result in reduced vaccine effectiveness against the H3N2 influenza virus. However, the vaccine can still provide some protection against H3N2 and can offer protection against other strains such as A (H1N1) and B. Please continue to offer vaccine to eligible persons six months of age and older who have not yet received an influenza vaccine this season.

Please also consider the timely administration of antivirals (e.g. oseltamivir or zanamivir) to recommended recipients presenting with influenza symptoms, regardless of immunization status in accordance with current AMMI guidelines available at: http://www.ammi.ca/guidelines. Laboratory confirmation of influenza in these individuals is not required prior to administering antiviral medication.

Antivirals are recommended for the following individuals outside of an institutional setting:

• those with influenza-like illness severe enough to require hospitalization; AND
• individuals with influenza-like illness at higher risk of complications from influenza infection as follows:
  • children aged younger than 5 years;
  • adults 65 years of age and older;
  • persons with chronic pulmonary (including asthma), cardiovascular (except hypertension alone), renal, hepatic, hematological (including sickle cell disease) or metabolic disorders (including diabetes mellitus), or neurologic and neurodevelopment conditions;
  • persons with immunosuppression, including that caused by medications or by HIV infection;
  • women who are pregnant or postpartum (within 4 weeks after delivery);
  • Indigenous people;
  • persons aged younger than 18 years who are receiving long-term aspirin therapy; 0 persons who are morbidly obese (i.e., body-mass index is equal to or greater than 40).

Antiviral recommendations for institutional settings

General practice in the management of influenza outbreaks in long-term care homes is to provide antivirals to all residents during an influenza outbreak, regardless of immunization status, as well as to unimmunized staff. In addition, when the circulating strain is not well-matched to the vaccine, antiviral prophylaxis should be offered to all staff, regardless of vaccination status, until the outbreak is declared over.
In light of the potential vaccine mismatch, it is currently recommended that during long-term care home outbreaks of influenza A, antivirals be offered to all staff, including those who have been immunized. All influenza A/H3N2 isolates tested to-date by the National Microbiology Laboratory have been found to be susceptible to oseltamivir and zanamivir. Oseltamivir is generally the preferred drug for outbreak management.

In contrast to exclusion policies recommended for unvaccinated staff members, it is not recommended that vaccinated staff members who refuse antiviral medication be excluded from work.

Further information on these recommendations, including appropriate infection prevention and control measures, are contained within the document entitled A Guide to the Control of Respiratory Infection Outbreaks in Long-Term Care Homes, 2014.

Please contact my office should you have any questions or comments.

For all reporting, inquiries or comments, please contact the Sudbury & District Health Unit at 705.522.9200, ext. 301.

Sincerely,
P. Sutcliffe, MD, MHSc, FRCPC
Medical Officer of Health

This item was last modified on September 9, 2016