THE EFFECT OF REPEATED FOUR MONTHLY TREATMENTS ON THE PREVALENCE AND WORM BURDEN OF ASCARIS, TRICHURIS AND HOOKWORM INFECTIONS IN AN ENDEMIC AREA

The effect of repeated 4 monthly treatment of single dose of 400 mg albendazole on the prevalence and worm burden of Ascaris, Trichuris and hookworm was studied in an endemic area. Repeated 4 monthly treatment, had significant effect in reducing the worm burden of Ascaris and not the prevalence. As for hookworm infection repeated 4 monthly treatment had significant impact in reducing both prevalence and worm burden in the community. However, repeated 4 monthly treatments had no significant impact in reducing the prevalence and worm burden of Trichuris infection in the community. Trichuris infection should be considered as a continuing infection rather than reinfection because of poor cure rate of albendazole at the onset of the study. Significant and strong predisposition (p < 0.0001) were detected after single and repeated 4 monthly treatment in Ascaris and Trichuris infection but not in hookworm infection. Stratification of data indicated that significant and strong predisposition was also seen in gender. This study concludes that changes in mean egg count per gram (mean EPG) is a sensitive indicator in measuring effect of treatment in an endemic area, and repeated 4 monthly treatments has successfully reduced the worm burden of Ascaris and hookworm infection. Subjects remained predisposed to Ascaris infection over 2 reinfection periods, and for hookworm infection evidence of predisposition was seen only over 1 reinfection period.