Unresolved fever in methicillin-sensitive Staphylococcus aureus bacteremia: Insights from a case without an identifiable source

Background

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a serious infection that requires timely diagnosis and treatment to prevent complications. Persistent fever after clearing bacteremia is uncommon, especially with normal inflammatory markers and no clear source of infection. This presents a significant diagnostic and management challenge.

Case presentation

A 36-year-old man presented with a three-day history of intermittent fever and was diagnosed with MSSA bacteremia. Initial investigations revealed mild splenomegaly. Despite treatment with intravenous flucloxacillin and negative repeat blood cultures, the fever persisted, prompting further evaluation. Advanced imaging did not reveal the source of infection. After completing a 14-day course of flucloxacillin, the fever resolved, and the patient recovered completely.

Conclusion

This case highlights the challenges in managing MSSA with persistent fever and no clear source of infection. This emphasizes the importance of adhering to evidence-based therapy and thorough evaluations, even when clinical presentations deviate from the typical course.