Patterns may be shaped by biology and gender-related care Bloodstream infections From diagnosis to antibiotic exposure and survival.
Sex differences in bloodstream infections
Bloodstream infections remain a major global cause of mortality, with management complicated by antimicrobial resistance, comorbidities, immunosuppression, and deep infections involving medical devices. A new review highlights gender as an under-reported factor that may influence the epidemiology, management and outcomes of bloodstream infections.
Current evidence suggests that the incidence of bloodstream infections is generally higher in males. A large group from the United States reported that the infection rate was higher among males than females, at 237 versus 156 per 100,000 people per year, and the gap was more pronounced among older males. Similar results from Norwegian and Swiss surveillance data showed a higher overall incidence of bloodstream infections in males, although E. coli bloodstream infections occurred more often in females. An increased risk of S. aureus bloodstream infection appears to be the main driver of the higher infection rate in males.
Biology, description and diagnosis
Sex-related immune differences may affect how bloodstream infections develop and progress. Females tend to show a lower susceptibility to severe bacterial infections and faster clearance of pathogens, which may reflect the immune-boosting effects associated with estrogen and the immunosuppressive properties of testosterone. However, the review emphasizes that immune differences are complex and also include genetics, immune cell function, and host-pathogen interactions.
Sex-related differences also extend to antimicrobial therapy. Females are more likely to receive antibiotics, and these prescriptions are often inappropriate, including for viral infections. In severe infections, several studies have reported that antibiotic administration takes longer in females with sepsis, as well as decreased adherence to sepsis bundle protocols.
Diagnostic gaps may also impact care. In S. aureus bloodstream infections, female patients were less likely to undergo echocardiography and receive shorter courses of antibiotics. In a European intensive care group of patients with pneumonia, females were less likely than males to undergo bronchoscopy.
Toward individualized care for infections
Pharmacokinetic and pharmacodynamic differences may further influence the treatment of bloodstream infections. Gender can influence absorption, distribution, metabolism and excretion, while adverse drug reactions occur more frequently in females across many drug classes, including antibiotics. Reported examples include an increased risk of hypokalemia with high-dose flucloxacillin and increased QT interval prolongation with moxifloxacin.
Results vary depending on the pathogen. Mortality appears to be higher in females with S. aureus bacteremia, while mortality differences due to Gram-negative bloodstream infections may be partly explained by the source of infection. These findings suggest a complex interplay between sex, pathogen, source, diagnostic intensity, and therapeutic decisions.
The review concluded that sex and gender influence nearly every aspect of bloodstream infections, yet sex-disaggregated data are still inconsistently reported. More sex-responsive study designs, better reporting, and increased awareness could support more individualized treatment strategies for all patients with bloodstream infections.
reference
Westgest AC et al. The influence of gender on treatment, epidemiology, and outcomes of bloodstream infections. Expert review of anti-infective therapy. 2026;doi:10.1080/14787210.2026.2692486.
Featured Image: NanSan on Adobe Stock.
