Patient characteristics and laboratory diagnosis of adults hospitalised with influenza, 2007–2008 (n=754)
| Patient characteristics | n (%) |
| Age ≥70 years | 454 (60.2) |
| Gender, male | 372 (49.3) |
| Nursing home residents | 141 (18.7) |
| Co-morbidity, any* | 456 (60.5) |
| Major co-morbidity (congestive heart failure, cerebrovascular, neoplastic, chronic liver and renal diseases, ischaemic heart diseases, diabetes mellitus and use of immunosuppressants) | 364 (48.3) |
| Chronic lung diseases (COPD, asthma, bronchiectasis and pulmonary fibrosis) | 166 (22.0) |
| Diagnoses | |
| Influenza A | 539 (71.5) |
| Influenza B | 215 (28.5) |
| Rapid diagnosis positive by IFA | 558 (74.0) |
| Rapid diagnosis positive by ICA | 74 (9.8) |
| Rapid diagnosis negative by IFA or ICA | 122 (16.2) |
| Positive virus culture | 667 (88.5) |
| Influenza A, subtype H3 | 414 (76.8) |
| Influenza A, subtype H1 | 56 (10.4) |
| Subtyping results unavailable | 69 (12.8) |
↵* Patients may have ≥1 co-morbid illness19 25 26. Data on influenza vaccination status were only available in 322 patients; among these, 21.4% had received influenza vaccines prior to the ‘flu’ seasons (similar to our previous report).19
COPD, chronic obstructive pulmonary disease; ICA, immunochromatographic assay; IFA immunofluorescence assay.