Risks for Childhood Bone and Joint Infection: A Case Control Study.

AIM: Despite status as a high-income nation, New Zealand (NZ) experiences the second highest rate of childhood bone and joint infection (BJI) globally with a disproportionate burden in Māori and Pacific children. This study aims to identify potentially modifiable risk factors for childhood BJI. METHODS: An age and ethnicity matched case-control design was utilised to compare acute cases of BJI with healthy controls recruited from orthopaedic fracture clinics. Cases were </= 15 years hospitalised because of acute haematogenous osteomyelitis or septic arthritis across multiple centres in the North Island of NZ. A pre-tested questionnaire was used to measure exposures including household income and crowding, healthcare access and eczema and eczema treatment. RESULTS: Ninety-nine cases and 309 controls consented to participate. Median age for cases was 8 years. The odds of having BJI were increased by eczema diagnosis (aOR 2.6, p = 0.0001). Eczema diagnosis posed greater risk for Māori (aOR 3.8, p = 0.01) and Pacific children (3.3, p = 0.004). Children with eczema who received treatment (tablets, creams or other) did not experience greater odds of BJI (aOR 1.05, p = 0.85). Having income in the form of salary or rent was associated with reduced odds of BJI development (aOR 0.44, p = 0.02). Eczema remained independently associated with BJI after adjustment for socioeconomic factors and healthcare access (adjusted OR 2.23, 95% p = 0.02). CONCLUSIONS: This case-control study has shown up to three times higher disease risk with eczema. This risk becomes negligible when eczema is treated, which should inform public health measures to lower disease burden.