Outcome of group B streptococcal prosthetic hip infections compared to that of other bacterial infections

BackgroundOutcome of streptococcal prosthetic hip infection is often thought to be better than that caused by other pathogens. That supposition was not confirmed in our experience with group B streptococcal prosthetic joint infection.ObjectiveWe compared outcomes of group B streptococcal and other-pathogen prosthetic hip infections.MethodsOne hundred and thirty nine patients, 24 with group B streptococcal and 115 other-pathogen prosthetic hip infections, were included. The primary outcome was the time from surgical treatment to treatment failure, defined as relapse, infection- or treatment-related death. Secondary outcomes were the times from surgical treatment to relapse or any event (event-free survival). The cumulative incidence estimator was used to model primary and secondary outcomes. Multivariable regression analysis was used to determine a set of independent predictors of treatment failure.ResultsWith a median follow-up of 22 months, treatment failed more frequently in patients with group B streptococcal prosthetic hip infections (hazard ratio, 4.88 [95% CI, 1.4–17], P = .012). Multivariable analysis retained the American Society of Anesthesiologist score and group B streptococcal infection as independent risk factors of treatment failure; event-free survival was lower for these patients (hazard ratio, 2.64 [95% CI, 1.2–6], P = .02).ConclusionDespite high antibiotic susceptibility, outcomes of group B streptococcal and other-pathogen prosthetic hip infection differ.