Women were found more likely than men to die following Staphylococcus aureus bacteremia in both a national cohort study and a meta-analysis.
More women than men were found to die from sepsis following Staphylococcus aureus bacteremia (SAB) in a large-population cohort studythat corroborated a systematic review and meta-analysis finding of sex disparity in all-cause mortality after SAB.1-2
"The findings from our cohort study reaffirms the observed increased mortality among female patients with SAB. Furthermore, our data suggest that sepsis-related mortality in particular was the underlying cause of this disparity," report Bethan Carter, MB, BCh, Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK, and colleagues.
Carter and colleagues had identified 7,515 adult patients (2760 female) with SAB between April 2010 and March 2022 in health-record data from Wales. Analyses of all-cause mortality within 30 and 90 days were adjusted for multiple variables, including age, hospital or community onset, methicillin sensitivity, and comorbidities. In addition, the investigators approximated individuals' resources and access to healthcare by application of the Welsh Index of Multiple Deprivation; and applied an index of frailty composed of 36 variables such as symptoms, signs, diseases, disabilities and laboratory results.
The investigators reported a 27% overall mortality at 30 days after SAB; with 29% mortality in women and 27% in men. Overall mortality at 90 days was 36%; with 37% in women and 36% in men.The higher all-cause mortality in women was statistically significant in unadjusted models at 30 days; and at both 30 and 90 days in the adjusted models.A regression analysis model of competing risks for 30-day mortality attributed the higher mortality in women to sepsis (hazard ratio, 1.21 [95% CI 1.02-1.44).
Women experienced significantly higher sepsis-related mortality following Staphylococcus aureus bacteremia (SAB) than men.
The study highlights potential sex-based differences in immune response and health care delivery.
The findings underscore the importance of researching sex differences across diseases, particularly in outcomes of bacterial infections like SAB.
"Greater sepsis-related mortality and higher C-reactive protein in females may be indicative of sex-based differences in immune response to SAB, potentially influenced by X-chromosome genetic polymorphisms and variations in Toll-like receptor expression and signaling," Carter and colleagues posited.
In invited commentary,3 Judith Regensteiner, PhD, Ludeman Family Center for Women's Health Research, Department of Medicine, University of Colorado Anschutz Medical Campus School of Medicine, Aurora, CO, and colleagues suggested other possible contributing factors, including sex differences in sources of SAB or in health care delivery.
"Importantly, the finding of greater mortality from SAB in women than men affirms that sex differences may exist in surprising and unexpected areas of health and leads to the question of how many such differences exist," Regensteiner and colleagues observe.
Regensteiner and colleagues point to the presence of sex differences across a broad range of diseases and note, as in heart disease, that the difference can be in presentation as well as outcome.
"SAB is one little-known but highly relevant example, and there are surely many more," they indicate."For example, it might be fertile ground to review other serious bacteremia infections for sex differences as a possible insight into the mechanisms."
Carter and colleagues agree on the need for, and potential benefit of research into sex differences."Further research is necessary to investigate underlying pathophysiological, social, and health-care-related factors that underpin sex-related mortality differences in SAB," they indicate.
"Addressing these disparities could lead to more targeted therapies, improved survival rates, and more equitable health care outcomes for both sexes," Carter and colleagues conclude.
