Control of geohelminths by delivery of targeted chemotherapy through schools

This study describes the age-targeted chemotherapeutic control of geohelminthiasis in the total population (n = 11,500) of the island of Montserrat, West Indies. The intervention programme involved the treatment with single dose albendazole of all children aged 2-15 years (approximately 2500) in 4 sequential cycles at intervals of 4 months. Infection status was monitored by an initial coprological survey of an age-stratified sample (11.5%) of the population, and by surveys of smaller samples (4-5%) after 2 and 4 cycles of treatment (7 and 15 months respectively). The programme delivered treatment to greater than 90% of the target population in each cycle, and reduced the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiura infection in the target age-class. A decline in infection was also observed in the 16-25 year age-class, even though less than 4% of adults received treatment. The study demonstrates that chemotherapy targeted only at children can be implemented within an existing health infrastructure, and can achieve an overall reduction in the prevalence and intensity of geohelminth infection.