Follow-up of Ascaris lumbricoides and Trichuris trichiura infections in children living in a community treated with ivermectin at 3-monthly intervals

Ivermectin treatment was administered every 3 months over a 1-year period ( April 1993-April 1994) to the whole eligible population of a village in Sou th Cameroon where both Ascaris lumbricoides and Trichuris trichiura were hy per-endemic. A parasitological stool examination was performed before each treatment. Thirty children, aged 5-15 years, were not only found egg-positi ve for A. lumbricoides and/or T. trichiura before the first treatment but w ere also each treated and examined in each treatment round. Among these chi ldren, the intensity of infection with A. lumbricoides decreased significan tly following the first treatment but thereafter remained steady. In contra st, the repeated ivermectin treatments had no significant impact on the int ensity of the T. trichiura infections or on the prevalence of infection wit h T. trichiura or A. lumbricoides among the 30 children.