Table 1.
Descriptive Data on Clinical Characteristics, Severity, and Outcomes of 275 Chinese Patients with Confirmed H7N9 or H1N1pdm09 Influenza Infections
| Variable | H7N9 (n = 51) |
H1N1pdm09 (n = 224) |
|---|---|---|
| Age, mean ± SD, years | 56.7 ± 22.7 | 50.8 ± 19.4 |
| Sex, male (%) | 36 (70.6) | 109 (48.7) |
| Major comorbidity (%)a | 16 (34.0) | 86 (38.6) |
| Onset-to-presentation, mean ± SD, days | 7.2 ± 3.3 | 3.0 ± 3.3 |
| Hospitalization (%) | 47 (92.2) | 169 (75.4) |
| Pneumonia, radiographic (%) | 42 (82.4) | 113 (50.7) |
| Supplemental oxygen use (%) | 37 (77.1) | 120 (53.8) |
| Acute respiratory failure (%)b | 26 (55.3) | 57 (25.4) |
| Death (%) | 10 (22.2) | 23 (10.3) |
| NAI treatment within 2 days from onsetc |
5 (10.6) | 135 (60.8) |
All H7N9 cases were enrolled in mainland China institutes (2013, 2014, 2015 outbreaks); H1N1pdm09 cases were from both Hong Kong and mainland China institutes (2011, 2013, 2014 seasonal peaks of H1N1pdm09; low-level circulation in 2012). Vaccines against human H7N9 infection were unavailable; a low (18%) vaccination rate among H1N1pdm09 patients was noted in the available records, consistent with our previous reports [4, 5].
Abbreviations: H1N1pdm09, pandemic influenza virus; H7N9, avian influenza virus; NAI, neuraminidase inhibitor.
aDefined as congestive heart failure; cerebrovascular, neoplastic, or chronic liver or renal diseases; chronic lung diseases; and diabetes mellitus, chronic cardiovascular, autoimmune or neurological diseases; or immunosuppression (not hypertension or hypercholesterolemia alone). Obesity is uncommon in our Chinese cohort [2, 4, 5].
bDefined as acute hypoxemic respiratory failure, requiring mechanical ventilation or noninvasive positive-pressure ventilation, and/or oxygen therapy for vital life support [4, 5].
cAltogether, 258/275 (93.8%) patients had received oseltamivir treatment; 140/275 (50.9%) were treated within 2 days from onset.