Outbreak of Kingella kingae skeletal system infections in children in daycare

OBJECTIVE: The objective of this study is to describe the investigation of an outbreak of one culture-proven and two presumptive cases of Kingella kingae osteomyelitis detected within a 15-day period in a daycare center in Israel. METHODS: Surveillance pharyngeal cultures were obtained from all attendees at the index daycare center and from two neighboring facilities. Combined amoxicillin-rifampin prophylaxis was administered to all children aged 6 to 30 months living in the community. K. kingae isolates were typed by pulsed field gel electrophoresis, random amplified polymorphic DNA analysis and sequencing of the rRNA genes. RESULTS: Surveillance cultures showed that four of 11 attendees at the index facility as well as five of 12 and one of 15 attendees at neighboring daycare centers carried K. kingae. Typing of isolates showed that the isolate from a child with osteomyelitis was identical to all other isolates from the same daycare center and different from organisms derived from the other facilities. Administration of prophylactic antibiotics resulted in partial eradication of the organism. CONCLUSIONS: Dissemination of K. kingae in a susceptible pediatric population may result in an outbreak of invasive disease. Our experience suggests the need for increased alertness for clusters of K. kingae infections among children in daycare.