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The following is a summary of “Frequency of haematogenous periprosthetic joint infection due to bacteraemia caused by gram-positive cocci,” published in the March 2025 issue of Infectious Diseases by Thompson et al. 

A prosthetic joint carries a lifelong risk of hematogenous periprosthetic joint infection (hPJI) during bacteraemia, with reported frequencies varying widely, reaching up to 40% for Staphylococcus aureus and 20% for streptococci.  

Researchers conducted a retrospective study to examine the frequency of hPJI from bacteraemia caused by virulent gram-positive cocci in individuals with hip and/or knee prostheses.  

They used a population- and register-based approach, cross-matching blood cultures positive for virulent gram-positive cocci with data from the Swedish Arthroplasty Register. Individuals with at least 1 prosthesis during bacteraemia were identified. Medical records were reviewed for concordant microbiological cultures in blood, synovial fluid, tissue, or bone to confirm hPJI. Absence of concordant cultures was considered absence of hPJI.  

The results showed that among 2,392 bacteraemia episodes, 143 (6%) led to at least 1 hPJI. The highest hPJI rates were observed with S. aureus (9.6%) and Streptococcus agalactiae (9.3%). A higher number of prostheses, male sex, and younger age were independently linked to hPJI. Bacteraemia from species other than S. aureus or S. agalactiae had a lower hPJI risk.  

Investigators concluded that the observed risk of hPJI following bacteraemia with virulent gram-positive cocci was significantly lower than previously reported, specifically showing a 9.6% frequency for S. aureus. 

Source: tandfonline.com/doi/full/10.1080/23744235.2025.2476530