Severe community-acquired pneumonia due to Staphylococcus aureus, 2003-04 influenza season

Abstract

During the 2003-04 influenza season, 17 cases of Staphylococcus aureus community-acquired pneumonia (CAP) were reported from 9 states; 15 (88%) were associated with methicillin-resistant S. aureus (MRSA). The median age of patients was 21 years; 5 (29%) had underlying diseases, and 4 (24%) had risk factors for MRSA. Twelve (71%) had laboratory evidence of influenza virus infection. All but 1 patient, who died on arrival, were hospitalized. Death occurred in 5 (4 with MRSA). S. aureus isolates were available from 13 (76%) patients (11 MRSA). Toxin genes were detected in all isolates; 11 (85%) had only genes for Panton-Valentine leukocidin. All isolates had community-associated pulsed-field gel electrophoresis patterns; all MRSA isolates had the staphylococcal cassette chromosome mec type IVa. In communities with a high prevalence of MRSA, empiric therapy of severe CAP during periods of high influenza activity should include consideration for MRSA.

Figure

Dendrogram of Staphylococcus aureus isolates determined by using SmaI–digested DNA recovered from patients with community-acquired pneumonia associated with influenzalike illness, influenza season, 2003–04. NA, not applicable (methicillin-susceptible); SE, staphylococcal enterotoxin A, B, C, H; REF, reference strain; PVL, Panton-Valentine leukocidin; TSST, toxin shock syndrome toxin; CHL, chloramphenicol; CLI, clindamycin; ERY, erythromycin; GM, gentamicin; LEV, levofloxacin; OX, oxacillin; PEN, penicillin; TET, tetracycline. *Inducible clindamycin resistance.