Public Health Importance of Methicillin-Sensitive Staphylococcus aureus (MSSA): Results From Pilot Surveillance in Five Counties, 2014–2015
Year: 2015
Type: article
Study design: Observational Study
Abstract: Background. Strategies for preventing Staphylococcus aureus infections have focused primarily on methicillin-resistant S. aureus (MRSA) rather than methicillin-sensitive S. aureus (MSSA). We conducted a pilot of public health surveillance for invasive MSSA infections to describe the public health impact of MSSA and whether populations at risk for MSSA versus MRSA differed. Methods. Active, population-based and laboratory-based surveillance was performed for invasive MRSA and MSSA in 5 counties from 4 states for 3–6 months during 2014–2015 (surveillance population: 4.0 million). A case was isolation of MRSA or MSSA from a normally sterile body site in a surveillance area resident. Cases were healthcare-associated if occurring on day ≥4 of hospitalization or in a patient with ≥1 healthcare exposure risk factors (hospitalization, long-term care facility [LTCF] residence, surgery, or dialysis in the prior year; or central venous catheter within 2 days prior). Descriptive analyses were performed and multivariate logistic regression used to obtain adjusted odds ratios (aORs) and confidence intervals (CIs) for independent factors more associated with MRSA than MSSA. Results. Complete case reports were obtained for 855 invasive S. aureus cases: 329 (38.5%) MRSA and 526 (61.5%) MSSA. The % MRSA varied across sites (range: 34%–52%). The site with the lowest %MRSA had the highest invasive S. aureus incidence (range: 23.1–49.2 cases/100,000 persons). Most healthcare-associated cases (56.8%) and in-hospital deaths (55.1%) were from MSSA. Patients with MSSA also tended to be younger (median age: 58 [MSSA] versus 63 years [MRSA], P = 0.002) and healthier (16.7% [MSSA] versus 7.6% [MRSA] without underlying medical conditions, P = 0.0001). In multivariable analysis of patient and healthcare risk factors, female gender (aOR 1.40, 95% CI, 1.04–1.89), chronic pulmonary disease (aOR 1.47, 95% CI, 1.02–2.13), decubitus ulcer (aOR 2.81, 95% CI, 1.43–5.52), intravenous drug abuse (aOR 1.81, 95% CI, 1.08–3.03) and prior LTCF residence (aOR 3.81, 95% CI, 2.56–5.69) were associated with MRSA. Notably, 65.3% of cases in previous LTCF residents were MRSA versus 34.1% in other patients (P < 0.0001). Conclusion. Strategies for preventing MSSA infections are needed to reduce the burden of healthcare-associated infections and deaths from S. aureus. MRSA-specific prevention efforts appear to be particularly needed in LTCFs. Disclosures. All authors: No reported disclosures.
Source: Open Forum Infectious Diseases
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $4,053
OpenAlex ID: W2341440887