Differences in prevalence of community-associated MRSA and MSSA among U.S. and non-U.S. born populations in six New York Community Health Centers

Abstract

Background Staphylococcus aureus is the most common cause of Skin and Soft Tissue Infections (SSTIs) in the community in the United States of America. Community Health Centers (CHC) serve as primary care providers for thousands of immigrants in New York. Methods As part of a research collaborative, 6 New York City-area CHCs recruited patients with SSTIs. Characterization was performed in all S. aureus isolates from wounds and nasal swabs collected from patients. Statistical analysis examined the differences in wound and nasal cultures among immigrant compared to native-born patients. Results Wound and nasal specimens were recovered from 129 patients and tested for antibiotic susceptibility. 40 patients were immigrants from 15 different countries. Although not statistically significant, immigrants had lower rates of MRSA infections (n=15) than did native-born participants, and immigrants showed significantly higher rates of MSSA wound cultures (n=11) (OR=3.5, 95% CI: 1.3, 9.7). Conclusions In our study, immigrants were more likely to present with SSTIs caused by MSSA than US-born patients. This suggests that antibiotic resistance may vary regionally and that immigrants presenting with SSTIs may benefit from a broader range of antibiotics. Immigrants also reported lower frequencies of antibiotic prescription or consumption in the months prior to SSTI infection.

Comparative Effectiveness Study of Home-Based Interventions to Prevent CA-MRSA Infection Recurrence

“…We conducted pre-specified subgroup analyses using logistic regression with treatment assignment and with each subgroup coded as dummy variables. Consistent with previous studies [ 21 ], foreign-born participants were more likely to have MSSA+ than MRSA+ wound cultures. Other HTE subgroup comparisons (wound culture type (MRSA vs. MSSA), birthplace (USA vs. non-USA), household contamination levels (low vs. high), household members colonization (present vs. absent), pets living in the household (present vs. absent), recruitment site (ED vs. FQHC), and baseline I&D treatment (yes vs. no)) revealed no statistically significant differences for EHR-documented SSTI recurrence (data not shown).…”

“…This RCT included practicing clinicians, patients, clinical and laboratory researchers, NY-based Federally Qualified Health Centers (FQHCs) and community hospital Emergency Departments (EDs). The stakeholder research collaborative expands an earlier partnership, the Community-Acquired MRSA Project (CAMP1) which developed research to address CA-MRSA [ 21 , 40 , 41 , 42 ]. The study was approved by Institutional Review Boards at Clinical Directors Network and Rockefeller University.…”

Comparative Effectiveness Study of Home-Based Interventions to Prevent CA-MRSA Infection Recurrence

“…We conducted pre-specified subgroup analyses using logistic regression with treatment assignment and with each subgroup coded as dummy variables. Consistent with previous studies (28), foreign-born participants were more likely to have MSSA+ than MRSA+ wound cultures. Other HTE subgroup comparisons [wound culture type (MRSA vs MSSA), birthplace (USA vs non-USA), household contamination levels (low vs high), household members colonization (present vs absent), pets living in the household (present vs absent), recruitment site (ED vs FQHC), and baseline I&D treatment (yes vs no)] revealed no statistically significant differences for EHR-documented SSTI recurrence (data not shown).…”

“…Although the perceived (or actual) intrusiveness of home visits proved difficult to overcome, the “warm hand-off” strategy facilitated a modest improvement in home visit completion rates (69). The lower-than-expected six-month recurrence rate (10.9% here as compared to our previous observational study of 33.3% (28)) may have limited the power to identify a treatment effect. Multiple well-designed studies conducted in different settings have all converged on similar findings: decolonization and decontamination can be accomplished in the household to varying degrees, but extensive, long-term decontamination may be required to achieve a medically meaningful reduction in disease recurrence.…”

“…Sample size estimation was based on SSTI recurrence rate from CAMP1, where 33.3% experienced an recurrence during the six months following their index SSTI (28); previous studies of HA-MRSA reported reductions between 30% and 55% (39-41) To achieve 80% power at 5% significance level in a two-sided Chi Square/Fisher’s Exact test for recurrence at 6-month follow-up, estimated sample size requirement was 120 participants (60 per group).…”