TABLE 1.
Demographic and microbiologic characteristics of patients and S. aureus subtypes
| Subtype | No. of isolates | Mean patient age (yr [SD]) | % female patients | CCIa (mean [median]) | Site of infection (%) |
% community onset infections | |||
|---|---|---|---|---|---|---|---|---|---|
| Blood | Lung | SSI | Other | ||||||
| All S. aureus | 45,707 | 58.8 (18.3) | 41 | 2.8 (2) | 16 | 34 | 28 | 22 | 62 |
| MRSA | 22,799 | 61.5 (18.1) | 42 | 3.0 (2) | 16 | 38 | 25 | 22 | 54 |
| MSSA | 18,154 | 55.6 (18.2) | 40 | 2.4 (2) | 17 | 30 | 31 | 22 | 69 |
| PSSA | 4,754 | 57.8 (18.1) | 40 | 2.6 (2) | 16 | 32 | 29 | 23 | 68 |
| P valueb | |||||||||
| MRSA vs MSSA | <0.0001 | 0.005 | <0.0001 | <0.0001 | <0.0001 | ||||
| MRSA vs PSSA | <0.0001 | 0.12 | <0.0001 | <0.0001 | <0.0001 | ||||
| MSSA vs PSSA | <0.0001 | 0.87 | 0.0005 | 0.0012 | 0.76 | ||||
a
CCI, Charlson comorbidity index; SSI, skin and soft tissue infection.
b
Tests of difference are two-sided and comprised t tests for age, chi-squared tests for sex, site of infection, and onset, and a Mann-Whitney test for CCI.