Volume 16, Number 5—May 2010
Research
Methicillin-Resistant Staphylococcus aureus Carriage and Risk Factors for Skin Infections, Southwestern Alaska, USA
A. Michal Stevens, Thomas W. Hennessy
, Henry C. Baggett, Dana Bruden, Debbie Parks, and Joseph Klejka
, Henry C. Baggett, Dana Bruden, Debbie Parks, and Joseph KlejkaTable 2
Staphylococcus aureus skin infections among study participants, by year, Alaska, 2000–2004*
| Skin infection outcome | MRSA carriers, n = 41 | MSSA carriers, n = 85 | Non–S. aureus carriers, n = 190 | p value |
|
|---|---|---|---|---|---|
| MRSA vs. non–S. aureus | MSSA vs. non–S. aureus | ||||
| Skin infection rate, % | |||||
| Year 1 | 56 | 32 | 30 | 0.001 | 0.77 |
| Year 2 | 37 | 26 | 30 | 0.42 | 0.50 |
| Year 3 |
32 |
21 |
21 |
0.15 |
0.98 |
| Cumulative % with >1 skin infection† | |||||
| Year 1 | 56 | 32 | 30 | 0.001 | 0.69 |
| Year 2 | 61 | 41 | 48 | 0.02 | 0.48 |
| Year 3 |
66 |
52 |
58 |
0.07 |
0.50 |
| 1st year of follow-up | |||||
| Mean no. skin infections‡ | 0.7 | 0.4 | 0.4 | 0.001 | 0.73 |
| No. (%) with >2 infections§ |
6 (15) |
7 (8) |
13 (7) |
0.10 |
0.68 |
| Entire follow-up period, 3.6 y | |||||
| Mean no. skin infections‡ | 1.9 | 1.2 | 1.1 | 0.03 | 0.60 |
| No. (%) with >3 infections§ | 13 (32) | 13 (15) | 24 (13) | 0.02 | 0.72 |
*MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible S. aureus. Skin infection rate per 100 persons in each of the 3 years; 2-sample Poisson test was used to compare skin infection rates.
†Comparisons made by use of Log-Rank statistic in Kaplan-Meier estimation of survival curve.
‡Comparisons made by use of Kruskal-Wallis statistic.
§Chi-square test used for calculation of p value.
