Antibiotic use in trachoma campaigns: height as proxy to weight in dosing of azithromycin in three Kenyan communities

Abstract

Background: Trachoma is the leading infectious cause of blindness with six out of 32 million Kenyansat risk. It is endemic in 18 of the 73 districts in Kenya, with a total population of 6 million. The worst affected provinces are Rift Valley, Eastern and Northeastern. Current trachoma control activities are limited to some districts in Kenya only, using the SAFE strategy. This study was necessitated by the need to facilitate the implementation of the 'Antibiotic' part of the SAFE strategy to the affected communities during mass treatment. Objective: To determine whether height can be used as an alternative to weight in dosing azithromycin among children aged 1-15 years. Methods: A community based cross sectional operational study was conducted in Kajiado, Baringo and West Pokot districts. Children aged 1-15 years were randomly selected and included in the study. Weight was measured using Salter digital scales and height was determined using a height stick.A 250 mg tablet of azithromycin which could be divided in to half to provide a dose of 125mg and 200mg / 5ml suspension was used to determine the doses of azithromycin. Normal tolerance limit was defined as 15mg - 30 mg / kg body weight. The data was entered into the computer and analyzed using the SPSS software package and regression analysis was done where appropriate. Results: A total of 2020 children were included. Of these 1033 (51.1%) were females and 987(48.9%) were males. Twenty five percent were in the age group ten to twelve. Generally, children from West Pokot were heavier and taller than those from Kajiado and Baringo (P< 0.001) Therewas a close relationship between weight and height and the distribution was near linear withmostpoints clustering near the 45° line. Height explained 92.8% of the variance of weight anddosage within tolerance limits could be predicted from height in 98.9% of the children. A height based dose stick that recommends the use of suspension and 125mg (half tablet) incremental,predicted doses within tolerance limits to 98.8% of children; while a height based dosestick that encompasses suspension for children less than four years and 1 tablet (250mg) incremental,predicted doses of97.5% of the children within tolerance levels. Conclusion A single height based dose stick can be used in the three Kenyan communities for the safe administration of azithromycin during mass campaigns Recommendations Further studies should be carried out in other trachoma endemic districts in order to develop a single model for height based dosage regime for the entire nation of Kenya. Manufacturers of azithromycin should look into the possibility of manufacturing 125 mg tablet for trachoma control purposes.