Review highlights the latest research in Kingella kingae and stresses that molecular tests are required for diagnosis

Aim: The aim of this study was to provide an update on paediatric Kingella kingae infections. Methods: We used the PubMed database to identify studies published in English, French and Spanish up to 15 November 2020. Results: Kingella kingae colonised the oropharynx after the age of 6 months, and the mucosal surface was the portal of entry of the organism to the bloodstream and the source of child-to-child spread. Attending day care centres was associated with increased carriage rate and transmission and disease outbreaks were detected in day care facilities. Skeletal system infections were usually characterised by mild symptoms and moderately elevated inflammation markers, requiring a high clinical suspicion index. The organism was difficult to recover in cultures and molecular tests significantly improve its detection. Kingella kingae was generally susceptible to beta-lactam antibiotics, and skeletal diseases and bacteraemia responded to antimicrobial, leaving no long-term sequelae. However, patients with endocarditis frequently experienced life-threatening complications and the case fatality rate exceeded 10%. Conclusion: Kingella kingae was the prime aetiology of skeletal system infections in children aged 6–48 months. Paediatricians should be aware of the peculiar features of this infection and the need to use molecular tests for diagnosis.