Estimating the burden of clinically significant Staphylococcus aureus infections and predictors for hospitalization for skin and soft tissue infections, Fulton County, GA, 2017

Abstract Background Incidence estimates of Staphylococcus aureus infections rarely include the full spectrum of clinically relevant disease from both community and healthcare settings. Methods We conducted a prospective study capturing all S. aureus infections in Fulton County, Georgia, during 2017. Medical records of patients with any incident infection (clinical cultures growing S. aureus from any site, without prior positive culture in previous 14 days) were reviewed. Estimates of disease incidence were calculated using age, race, and sex specific population denominators accounting for weighted sampling methods. Multivariable logistic regression models were used to identify risk factors for hospitalization among patients with skin/soft tissue infections (SSTIs). Results The overall incidence of clinically relevant S. aureus infection was 405.7 cases per 100,000 people (SE 5.62, range 400.1 - 411.3). Overall incidence for those of Black race was 500.84 cases per 100,000 people (SE 14.55), while White race patients had overall incidence of 363.67 cases per 100,000 people (SE 13.8). SSTIs were most common infection (2,351; 225.8 cases per 100,000 people, SE 7.1), and 30% required hospitalization. Among SSTI, after adjusting for invasive disease, cellulitis, diabetes, and demographics, independent predictors of hospitalization included MRSA (aOR 1.6; 95% CI 1.0 - 2.7), and homelessness (aOR 4.9; 95% CI 1.1-22) Conclusions The burden of clinically relevant S. aureus infections is high, particularly among the Black population, and risks for hospitalization among SSTI include isolate factors and factors related to patients’ vulnerability.