Height as proxy for weight in mass azithromycin dosing of Kenyan children with active trachoma

Abstract

Objectives: To determine whether height can be used as an alternative to weight in mass treatment of children aged 1-15 years with active trachoma using azithromycin and propose a height-based dose stick for Kenyan children. Design: community based operational research Subjects: A total of 2,020 children were included: 987(48.9%) male and 1033 (51.1%) female. 369 (18.3%) were from Kajiado, 772 (38.2%) from West Pokot and 879 (43.5%) from Baringo. Settings: The study was carried out in three trachoma endemic districts: West Pokot, Baringo and Kajiado. A baseline trachoma survey had been conducted in the three districts in preparation for the implementation of SAFE. Results: Children from West Pokot were heavier and taller than those from Kajiado and Baringo (P < 0.001). The body mass index (BMI) of the children in the three study areas was comparable. There was a close relationship between weight and height and the distribution was near linear. Height explained 92.8% of the variance of weight. A height based dose stick that recommends the use of 40mg/ml suspension and 125mg (half tablet) incremental dosage predicted doses within tolerance limits (15-30mg/kg) to 98.8% of children and 100% with extended dose range (13 -35 mg/kg). If 40mg/ml suspension and 1 tablet (250mg) incremental dosage were to be used, the height stick would predict doses within tolerance limits to 97.5% of the children and 99.9% with extended dose range (13 -35 mg/kg). Conclusions: The theoretical model based on the use of 40mg/ml suspension and 125mg (half tablet) incremental offers better dosing ranges to all the children of West Pokot, Baringo and Kajiado districts when the extended dosage range (13-35mgs/kg) is applied. Recommendations: Similar studies should be conducted in other trachoma endemic communities in Kenya to determine whether a single height-based dose stick can be used in the entire country. The manufacturer should look into the possibility of producing 125mg tablet for mass treatment.