Table 2.
Viral agents identified for outbreak-associated viral respiratory infections in Ontario, Canada, 2014–19
| Resident infections, n (n per 100 resident-years) | Resident deaths, n (n per 100 resident-years) | Case fatality, % | Outbreak frequency, n (n per home per year) | Mean outbreak size, n (mean % of home residents) | ||
|---|---|---|---|---|---|---|
| Overall | 64 829 (17·2) | 1969 (0·52) | 3·04% | 4921 (1·7) | 13·2 (11·5%) | |
| Single pathogens | ||||||
| Coronavirus* | 2385 (0·6) | 25 (0·01) | 1·05% | 197 (0·1) | 12·1 (10·8%) | |
| Human metapneumovirus | 1969 (0·5) | 59 (0·02) | 3·00% | 162 (0·1) | 12·2 (12·1%) | |
| Human parainfluenza virus† | 2829 (0·8) | 80 (0·02) | 2·83% | 232 (0·1) | 12·2 (10·8%) | |
| Influenza A | 22 159 (5·9) | 937 (0·25) | 4·23% | 1414 (0·5) | 15·7 (12·8%) | |
| Influenza B | 5289 (1·4) | 233 (0·06) | 4·41% | 391 (0·1) | 13·5 (11·8%) | |
| Respiratory syncytial virus | 3954 (1·0) | 116 (0·03) | 2·93% | 309 (0·1) | 12·8 (11·7%) | |
| Rhinovirus or enterovirus | 7316 (1·9) | 108 (0·03) | 1·48% | 591 (0·2) | 12·4 (10·9%) | |
| Other | 772 (0·2) | 36 (0·01) | 4·66% | 57 (0·0) | 13·5 (13·6%) | |
| Multiple pathogens | 4501 (1·2) | 162 (0·04) | 3·60% | 280 (0·1) | 16·1 (13·6%) | |
| Unidentified | 13 655 (3·6) | 213 (0·06) | 1·56% | 1288 (0·4) | 10·6 (9·8%) | |
*
Coronavirus strains OC43, 229E, NL63, and HKU1 were tested.
†
Human parainfluenza strains 1–4 were tested.