Table 1.
Characteristics of study population, by single or multiple virus detection
| All collected samples (n = 893) | No viruses detected (n = 327) | Single virus illnesses (n = 463) | Multiple virus illnesses (n = 103) | |
|---|---|---|---|---|
| Male, n (%) | 504 (56) | 181 (55) | 267 (58) | 56 (54) |
| Age at illness, n (%) | ||||
| 0 to <6 months | 257 (29) | 96 (29) | 143 (31) | 18 (17) |
| 6 to <24 months | 301 (32) | 88 (27) | 155 (33) | 58 (56) |
| 24 months and older | 335 (38) | 143 (44) | 165 (36) | 27 (26) |
| Underlying chronic conditions, n (%) | ||||
| Any | 396 (44) | 183 (56) | 179 (39) | 34 (33) |
| Asthma | 164 (18) | 61 (19) | 81 (17) | 22 (21) |
| Neurologic | 58 (6) | 28 (9) | 28 (6) | 2 (2) |
| Cardiac | 79 (9) | 40 (12) | 34 (7) | 5 (5) |
| Respiratory | 44 (5) | 25 (8) | 17 (4) | 2 (2) |
| Renal | 12 (1) | 4 (1) | 7 (2) | 1 (1) |
| Gastrointestinal | 15 (2) | 4 (1) | 9 (2) | 2 (2) |
| Hematologic | 24 (3) | 12 (4) | 7 (2) | 5 (5)* |
| Metabolic | 6 (1) | 2 (1) | 4 (1) | 0 (0) |
| Genetic | 57 (6) | 22 (7) | 31 (7) | 4 (4) |
| Malignancies | 58 (6) | 35 (11) | 21 (5) | 2 (2) |
| Sample collected within 1 day of admission, n (%) | 776 (87) | 251 (77) | 428 (92) | 97 (94) |
*P < 0·05 for difference between multiple virus illnesses and single virus illnesses.