Reduction in hookworm infection after praziquantel treatment among children and young adults in Leyte, the Philippines

Abstract

One small previous study found that praziquantel reduced hookworm infection. In this study, 607 subjects were enrolled in a longitudinal study. At enrollment and every 3 months for 18 months, three stool samples were collected, and the intensity of infection with Schistosoma japonicum and soil-transmitted helminths (STHs) was quantified. All subjects were treated with 60 mg/kg praziquantel at baseline. Three months post-treatment, the percent of subjects who were hookworm-infected decreased to 46.5% from 61% at baseline. The putative cure rate was 23.7%. The 95% confidence interval around the change in hookworm egg counts from baseline to 6 and 12 months post-treatment was negative and did not include zero. The percent reduction in hookworm egg counts from baseline to 3 months post-treatment was 40.8%. Praziquantel treatment did not decrease the infection intensity of STHs. Control programs using praziquantel may have the added benefit of reducing hookworm infection and anemia in areas of coendemnicity.

Figure 1.

Prevalence of hookworm infection by intensity and time point.

Figure 2.

Mean geometric mean egg count at baseline and follow-up time points for hookworm, Ascaris, and Trichuris. Error bars represent 95% confidence intervals. * P < 0.0001 compared with value at month 0 (baseline). ψ P < 0.001 compared with value at month 0 (baseline). This figure appears in color at www.ajtmh.org.

Figure 3.

Mean within-person change in geometric mean egg count from baseline to follow-up time points for hookworm, Ascaris, and Trichuris. Error bars represent 95% confidence intervals. This figure appears in color at www.ajtmh.org.