Osteomyelitis and septic arthritis due to Citrobacter freundii and Haemophilus influenzae type b

This report describes dual infection with Citrobacter freundii and Haemophilus influenzae type b causing septic arthritis and osteomyelitis of the elbow in a previously healthy 5-year-old boy. The patient was treated successfully with intravenous fosfomycin for 4 weeks. Infections with Citrobacter beyond the neonatal period are rare in paediatric patients. When Citrobacter spp. is isolated, coinfection with other bacterial pathogens should be considered.