A rare case of Haemophilus parainfluenzae periprosthetic joint infection: A case report with literature review.

INTRODUCTION

Haemophilus parainfluenzae is a common commensal of the upper respiratory tract and is an extremely rare cause of periprosthetic joint infections (PJI).

CASE PRESENTATION

A 92-year-old male presented with five days of right knee pain, reduced knee range of motion and raised inflammatory markers. He was diagnosed with a right total knee arthroplasty (TKA) PJI caused by Haemophilus parainfluenzae via knee aspiration fluid culture and was treated with debridement, antibiotics and implant retention (DAIR). Surgery was uneventful and he was treated with a six-week course of intravenous antibiotics followed by six months of suppression via oral antibiotics. At the one-year post-operative mark, there was no recurrence of infection.

DISCUSSION

There are only five reported cases of Haemophilus parainfluenzae PJI, of which only one case had no immunocompromised state or prior dental work. Our case is the second case in existing literature that involves PJI from this bacterium in a healthy individual with no identifiable risk factors. Though Haemophilus parainfluenzae is a rare cause of PJI, principles of surgical intervention and treatment in PJI still apply.

CONCLUSION

PJI caused by Haemophilus parainfluenzae is a rare occurrence. Prompt microbiological diagnosis is vital in ensuring favourable outcomes through surgical debridement combined with culture-directed antimicrobial agents in the treatment of rare infections such as this.