Research Summary

Does Long-Term Antimicrobial Suppression Prevent Streptococcal PJI Relapse?

Anthony Calabro, MA

Key Highlights

  • Suppression therapy improved long-term infection-free survival compared with standard treatment.
  • At 7.5 years, infection-free survival was 62% with suppression vs 38% with standard therapy (P = .038).
  • Relapse occurred in 25% of patients after suppression discontinuation.
  • Ongoing suppression prevented streptococcal reinfection, with failures during treatment linked only to gram-negative organisms.

Long-term suppression therapy was found to significantly reduce relapse in patients with streptococcal periprosthetic joint infection (PJI). In this prospective study, infection-free survival was substantially higher among patients who continued antimicrobial suppression compared with those treated with standard therapy alone. The findings suggest that extended suppression not only prevents reinfection during treatment but also confers a meaningful survival benefit over time.

Streptococcal PJI is a clinically challenging condition, often associated with high relapse rates despite conventional antimicrobial courses. Prior evidence indicated that suppression improves short-term outcomes, but its long-term effectiveness remained unclear. Given the morbidity and surgical complexity associated with PJI, clarifying whether ongoing suppression could sustain infection-free survival was a necessary step in guiding optimal treatment strategies.

Investigators conducted a prospective cohort study including consecutive patients with streptococcal PJI. Patients received either standard therapy (12 weeks of antimicrobials) or suppression therapy lasting longer than 6 months. Infection-free survival was analyzed using Kaplan-Meier estimates and compared between groups with the log-rank test. Pathogen distribution, surgical approaches, and failure patterns were also examined.

A total of 63 PJI episodes were analyzed. Thirty-three patients received standard treatment, while 30 underwent suppression therapy, of whom 10 were still receiving suppression and 20 had discontinued by follow-up. The most common pathogens were Streptococcus agalactiae (n = 20) and Streptococcus dysgalactiae (n = 18). Surgical strategies included two-stage exchange in 35 cases and prosthesis retention in 21. At 7.5 years, infection-free survival was markedly higher in the suppression group (62%) compared with the standard therapy group (38%) (P = .038). Streptococci accounted for 52% of all failures. Importantly, suppression prevented streptococcal reinfections during treatment; however, relapse or reinfection occurred in 25% of patients after suppression was discontinued. Failures during active suppression were exclusively attributable to gram-negative organisms, indicating suppression’s specific efficacy against streptococcal relapse.

“Suppression therapy significantly improves long-term outcome in streptococcal PJI,” the authors concluded. “While suppression effectively prevents streptococcal reinfections during treatment, the risk of recurrence reemerges after discontinuation.”

Reference
Dos Santos V, Meller S, Perka C, Trampuz A, Renz N. Ongoing suppression prevents relapse in streptococcal periprosthetic joint infection: A prospective long-term cohort study. J Infect. 2025;90(3):106437. doi:10.1016/j.jinf.2025.106437. Epub 2025 Feb 6.