Hip joint infection by Prevotella denticola in rheumatoid arthritis : A case diagnosed with metagenomic sequencing.

backgroundInfection, as a complication of rheumatoid arthritis (RA), has attracted increasing attention from rheumatologists. Here, we present the first case of RA with hip joint infection, which was driven by infection with Prevotella denticola. Anaerobic bacterial infection was identified by metagenomic next-generation sequencing (mNGS).

methodsWe describe the case of a 56-year-old woman with a history of RA who was admitted for intense hip joint pain and intermittent fever following long-term oral glucocorticoid (GC) treatment.

resultsAlthough blood and hip joint effusion cultures for aerobic and anaerobic organisms were negative, we considered the possibility of a clinical diagnosis of hip joint infection; therefore, empirical antibiotic treatment was initiated but it was ineffective in this case. Prevotella denticola was identified by mNGS from the hip joint effusion obtained via ultrasound-guided puncture and the organism was resistant to the initial antimicrobial treatment. Finally, the adjustment of antimicrobial treatment led to successful treatment.

conclusionPatients with RA have a significantly greater risk of infections than the general population; however, Prevotella denticola infection of the hip joint has not been previously reported. The combination of ultrasound-guided puncture and mNGS to accurately recognize and treat joint infection in patients with RA in a timely manner is necessary to prevent the development of complications, a strategy worthy of further clinical application.