Respiratory Watch: Development of a provincial system for respiratory syncytial virus surveillance in Nova Scotia, 2005-2008.

OBJECTIVE

Respiratory syncytial virus (RSV) is the most common cause of severe lower respiratory tract infection in young children and is increasingly recognized as a cause of influenza-like illness in those older than 65 years of age. A surveillance system to provide timely local information about RSV activity in Nova Scotia (NS) is described.

METHODS

A case report form was developed for weekly reporting of all laboratory isolates of RSV at diagnostic laboratories around the province. Laboratories were asked to send the forms by fax each Friday to the Nova Scotia Department of Health Promotion and Protection. Data were entered in Excel (Microsoft, USA) and aggregate results summarized by age, sex, health district and date of laboratory confirmation for 2005 to 2008.

RESULTS

During three winter seasons (2005-2006, 2006-2007 and 2007-2008), there were 207, 350 and 186 isolates of RSV reported in NS, respectively. The average incidences of RSV in NS varied greatly by age, with the highest rates in infants younger than 24 months of age, and approaching 4000 cases per 100,000 population in infants up to five months of age. The duration of the RSV outbreak was approximately five to six months each year, but the month of onset varied.

CONCLUSIONS

A RSV surveillance system was successfully established in NS that provides weekly data to the public health system, clinicians and infection control practitioners. The time of onset and severity of the RSV season varied over time. These data can be used to plan anti-RSV passive prophylaxis programs and infection control education, and distinguish RSV outbreaks from other viruses in acute care and long-term care settings.