Public Health Importance of Invasive Methicillin-sensitive Staphylococcus aureus Infections: Surveillance in 8 US Counties, 2016

Abstract

Background Public health and infection control prevention and surveillance efforts in the United States have primarily focused on methicillin-resistant Staphylococcus aureus (MRSA). We describe the public health importance of methicillin-susceptible S. aureus (MSSA) in selected communities. Methods We analyzed Emerging Infections Program surveillance data for invasive S. aureus (SA) infections (isolated from a normally sterile body site) in 8 counties in 5 states during 2016. Cases were considered healthcare-associated if culture was obtained >3 days after hospital admission; if associated with dialysis, hospitalization, surgery, or long-term care facility (LTCF) residence within 1 year prior; or if a central venous catheter was present ≤2 days prior. Incidence per 100 000 census population was calculated, and a multivariate logistic regression model with random intercepts was used to compare MSSA risk factors with those of MRSA. Results Invasive MSSA incidence (31.3/100 000) was 1.8 times higher than MRSA (17.5/100 000). Persons with MSSA were more likely than those with MRSA to have no underlying medical conditions (adjusted odds ratio [aOR], 2.06; 95% confidence interval [CI], 1.26–3.39) and less likely to have prior hospitalization (aOR, 0.70; 95% CI, 0.60–0.82) or LTCF residence (aOR, 0.37; 95% CI, 0.29–0.47). MSSA accounted for 59.7% of healthcare-associated cases and 60.1% of deaths. Conclusions Although MRSA tended to be more closely associated with healthcare exposures, invasive MSSA is a substantial public health problem in the areas studied. Public health and infection control prevention efforts should consider MSSA prevention in addition to MRSA.

Environmental Surveillance and Characterization of Antibiotic Resistant Staphylococcus aureus at Coastal Beaches and Rivers on the Island of Hawaiʻi

“…The MSSA all belong to well-known clones, such as ST398 MSSA, which is human-associated unlike the MRSA ST398 [ 32 ] and carries the erm (T) gene, which are not typically found in livestock-associated strains [ 33 ]. Furthermore, future in-depth studies should also focus on the epidemiology of MSSA, as these strains account for the majority of invasive S. aureus infections in the United States resulting in considerable morbidity and mortality, [ 34 ] and may also pose a health risk for beachgoers.…”

Clinical Characteristics and Outcome of Staphylococcus aureus Prostate Abscess From Ten Years of Experience at a Tertiary Care Center

“…Methicillin-resistant S. aureus was originally considered a hospital-associated infection, but infection in previously healthy individuals in the community emerged in the 1990s and, so, it now is referred to as community-associated MRSA (CA-MRSA) [6]. The incidence of invasive S. aureus infection has increased in recent years, with similar frequently reported infections irrespective of the methicillin-resistant status (except for the association of methicillin-susceptible S. aureus (MSSA) with septic arthritis), although smaller studies have reported more pneumonia, bacteremia or sepsis, and endocarditis among MRSA patients [7, 8].…”

Genomic Epidemiology and Global Population Structure of Exfoliative Toxin A-Producing Staphylococcus aureus Strains Associated With Staphylococcal Scalded Skin Syndrome

“…Genomic studies of S. aureus have historically focused on methicillin-resistant S. aureus (MRSA) due to challenges in treatment and poorer clinical outcomes ( Dasenbrook et al, 2010 ; Harkins et al, 2018 ; Kanjilal et al, 2018 ). Yet methicillin-susceptible S. aureus (MSSA) strains continue to cause significant morbidity and mortality ( Jackson et al, 2019 ). In particular, some S. aureus strains produce epidermolytic staphylococcal exfoliative toxins (ETs), extracellular proteins that cause separation of the epidermal layer of the skin.…”