Table 1. Demographic and clinical characteristics of cases of Staphylococcus aureus community-acquired pneumonia associated with influenzalike illness, influenza season 2003–04*.
| Characteristic | No. (%), N = 17 |
|---|---|
| Median age, y (range) | 21 (3 mo–62 y) |
| Sex, male | 8 (47) |
| Race | |
| White | 10 (59) |
| Black | 7 (41) |
| Underlying disease† | 5 (29) |
| MRSA risk factors‡ | 4 (24) |
| Documented influenza vaccination | 1 (6) |
| Evidence of influenza infection | |
| Laboratory-confirmed | 12 (71)§ |
| Rapid antigen test | 10 (59) |
| Paired serology | 2 (12) |
| Fluorescent antibody staining | 2 (12) |
| Clinical symptoms | |
| Cough | 14 (82) |
| Myalgias | 9 (53) |
| Sore throat | 6 (35) |
| Headache | 6 (35) |
| Shortness of breath | 5 (29) |
| Rigors | 4 (24) |
| Clinical signs | |
| Temperature >38°C | 12/13 (92) |
| Hypotension (systolic blood pressure <90 mm Hg) | 12/13 (93) |
| Normal or elevated leukocyte count† (>3,500/mm3) | 12/16 (75) |
| Median leukocyte count (range) | 16,500 mm3 (6,000–295,000) |
| Leukopenia (<3,500/mm3) | 4/16 (25) |
| Thrombocytopenia (<150,000/mm3) | 6/16 (38) |
| Radiologic documentation of pneumonia¶# | |
| Lobar | 3/16 (19) |
| Multiple lobe involvement | 4/16 (25) |
| Diffuse/patchy infiltrates | 6/16 (38) |
| Effusions/empyema | 5/16 (31) |
| Cavitation/necrosis | 4/16 (25) |
*MRSA, methicillin-resistant S. aureus. †One each of diabetes, multiple sclerosis, prune belly syndrome, cystic fibrosis, eczema. ‡Hospitalization, dialysis, surgery, or residence in a long-term care facility in the previous year; ever having an MRSA infection; and presence of percutaneous device or catheter at time of culture. §One patient had influenza infection confirmed by all methods. ¶One patient died on arrival at the hospital. #Not mutually exclusive.