Seasonal influenza report
Laboratory confirmed influenza A and B
Table 1: Number of laboratory-confirmed influenza cases* by episode date
Ottawa, September 1, 2012 to April 5, 2013
| Age (years) | 2012-2013 Season to Date |
Proportion of total laboratory-confirmed cases (%) |
|---|---|---|
| Less than 5 | 97 | 18.5 |
| 5 to 19 | 30 | 5.7 |
| 20 to 64 | 110 | 21.0 |
| 65+ | 286 | 54.7 |
| Total influenza cases | 523 |
*The cases in Table 1 represent only those individuals who submitted nasopharyngeal samples that tested positive for influenza A or B. This is estimated to be a small proportion of Ottawa’s population who had influenza and a possible over-representation of influenza incidence in the young and the elderly.
Figure 1: Number of reported laboratory-confirmed influenza cases by episode week and age group, Ottawa, September 1, 2012 to April 5, 2013
Source: Public Health Ontario, integrated Public Health Information System (iPHIS), extracted April 8, 2013
Institutional outbreaks
Ottawa Public Health investigates and reports on respiratory outbreaks in hospitals and long-term care facilities such as nursing homes, homes for the aged, and retirement homes.
There have been 54 institutional influenza outbreaks in Ottawa since the beginning of the influenza season (September 1, 2012).
Table 2: Institutional influenza outbreaks – cases*, mortality, and morbidity
Ottawa, September 1, 2012 to April 5, 2013
| Influenza Type | 2012-2013 Season to Date |
|---|---|
| A | 50 |
| B | 4 |
| A and B | 0 |
| Total | 54 |
| Residents | |
| Cases | 586 |
| Associated pneumonia | 33 |
| Associated hospitalizations | 83 |
| Associated deaths | 31 |
| Staff | |
| Cases | 268 |
Source: Public Health Ontario, integrated Public Health Information System (iPHIS), extracted April 8, 2013.
Please note that the season to date numbers may not total the previous week's numbers due to an on-going validation process.
Cases from institutional outbreaks include laboratory-confirmed cases and individuals with influenza-like illness (ILI)
Figure 2: Institutional Respiratory Outbreaks by Week of Onset Ottawa, September 1, 2012 to April 5, 2013
Source: Public Health Ontario, integrated Public Health Information System (iPHIS), extracted April 8, 2013
Influenza subtypes and strains
The following have been isolated from samples collected in Ottawa: Influenza A:H3N2, H1N1; Influenza B