Background: Many studies have shown that Staphylococcus aureus is a leading cause of both community onset and hospital onset bloodstream infections. However, relatively little is known about the occurrence and outcome of S. aureus bacteremia in sub-Saharan Africa. A previous report indicated that S. aureus accounts for 16% of community onset and 6% of hospital onset bloodstream infections at Aga Khan University Hospital Nairobi (AKUHN). Data about the etiology of S. aureus bacteremia in sub-Saharan Africa will help optimize recognition and treatment. This study was performed in order to understand the etiologies and risk factors for S. aureus bacteremia in a sub-Saharan location.
Materials and methods: A review of the electronic record of laboratory results from September 2010 through December 2018 identified 201 patients seen at AKUHN with S. aureus bacteremia. The source and/or focus of infection was identified and in-hospital mortality was determined. Cases with bacteremia after three days of hospitalization were considered hospital acquired. Community onset cases were divided into community acquired and health care associated.
Results: Most cases (71%; 143/201) were community onset, but only 41% (83/201) of these cases were community acquired. The most commonly identified foci of infection for community acquired bacteremia were musculoskeletal (25%; 21/83) and skin and soft tissue (24%; 20/83). The majority of health care associated (70%; 40/57) and hospital acquired cases (74%; 43/58) were associated with invasive vascular devices, with peripheral IVs being the most common for hospital acquired and dialysis catheters being the most common for health care associated infections. In-hospital mortality rates were 23% (19/83) for community acquired, 19% (11/57) for health care associated and 33% (19/58) for hospital acquired infections.
Conclusion: Invasive vascular devices were associated with a substantial portion of cases of S. aureus bacteremia and provide an important target for infection control efforts.