Table 1. Characteristics of patients hospitalized with influenza-associated acute lower respiratory infection – Sa Kaeo and Nakhon Phanom, Thailand, January 2009 – December 2010. Values represent n (%) unless otherwise stated.
| A(H1N1)pdm09 (N = 417) | A(H1N1) (N = 59) | A(H3N2) (N = 270) | A, unsubtyped (N = 32) | B (N = 120) | p-value | |
| Age, years, median (range) | 16 (0–92) | 14 (0–82) | 45 (0–95) | 15.5 (0–80) | 15 (0–86) | <0.01a |
| Age group, years | ||||||
| Age <5 | 86 (20.6)* | 8 (13.6) | 60 (22.2) | 5 (15.6) | 31 (25.8) | <0.01¥ |
| 5–17 | 136 (32.6) | 24 (40.7) | 30 (11.1) | 14 (43.8) | 39 (32.5) | |
| 18–49 | 117 (28.1) | 11 (18.6) | 56 (20.7) | 4 (12.5) | 25 (20.8) | |
| 50–64 | 45 (10.8) | 8 (13.6) | 59 (21.8) | 5 (15.6) | 7 (5.8) | |
| ≥65 | 33 (7.9) | 8 (13.6) | 65 (24.1) | 4 (12.5) | 18 (15.0) | |
| Temperature >38°C | 243 (58.4) | 36 (61.0) | 153 (56.7) | 16 (50.0) | 57 (47.5) | 0.17¥ |
| Fever by report | 409 (98.1) | 55 (93.2) | 266 (98.5) | 31 (96.9) | 118 (98.3) | 0.07¥ |
| Days in hospital, median | 3 | 3 | 3 | 3 | 3 | 0.71a |
| Death | 1 (0.2) | 0 | 3 (1.1) | 0 | 0 | 0.29¥ |
| Intubation | 7 (1.7) | 1 (1.7) | 2 (0.8%) | 0 | 1 (1.3) | 0.70¥ |
| Oxygen therapy | 79 (19.0) | 14 (23.7) | 71 (26.4) | 5 (15.6) | 20 (16.7) | 0.07¥ |
| Co-infections | ||||||
| RSV | 30 (7.2)b | 0 | 29 (10.9) | 1 (3.1) | 8 (6.7) | 0.03¥ |
| Adenovirus | 2 (0.48)b | 1 (1.7) | 0 | 0 | 0 | 0.20¥ |
| Streptococcus pneumoniae (urine antigen testing among age ≥18 years)* | 4 (2.1) of 188d | 0 of 27 | 8 (4.7) of 170d | 0 of 13 | 1 (2.1)of 47 | 0.38¥ |
| Blood culture positive of those with culture | 1 of 121c | 0 of 23 | 0 of 92 | 0 of 9 | 0 of 35 | |
| CXR with pneumonia (of those with CXR read) | 68 (33.7) of 202 | 9 (31.0) of 29 | 48 (32.2) of 149 | 5 (33.3) of 15 | 20 (35.1) 57 | 0.97¥ |
¥
Pearson chi-square test for homogeneity, excluding influenza A cases without subtype.
a
Kruskal-Wallis test, excluding influenza A cases without subtype.
*
Among those tested for Streptococcus pneumoniae by the Binax® urine antigen assay.
b
One A(H1N1)pdm09-infected patient was also positive for adenovirus and RSV.
c
One patient with Staphylococcus aureus.
d
One patient positive for both influenza A(H1N1)pdm09 and A(H3N2) tested positive for Streptococcus pneumoniae.
CXR, chest x-ray.