First case report of Rahnella bacteremia in a healthy child

Abstract

Background

Rahnella species are environmental Gram-negative bacilli rarely reported as human pathogens, typically in immunocompromised individuals or those with chronic medical conditions. We report the first known case of bacteremia caused by Rahnella species in a paediatric patient without comorbidities or identifiable risk factors.

Case Report

A previously healthy 4-year-old Swiss girl presented with prolonged fever and abdominal pain without a clear infectious focus. Laboratory tests showed leukocytosis and elevated inflammatory markers.

Results

Blood cultures grew Rahnella sp. Empirical treatment with intravenous ceftriaxone, later switched to meropenem due to a mild allergic reaction, led to rapid clinical improvement. The patient completed a 10-day antibiotic course and fully recovered without complications.

Conclusion

This case highlights the capacity of Rahnella sp. to act as a true pathogen even in patients without significant comorbidities. Our findings suggest a need to reconsider the clinical relevance of Rahnella sp., which may cause invasive infections in immunocompetent hosts—not just opportunistic disease in vulnerable populations.