Predictors of hookworm and Opisthorchis viverrini infection among adolescents in urban Laos: a cross-sectional study.

Purpose: Infection with hookworm and Opisthorchis viverrini are serious health problems among children and adolescents in Laos. In this study, we demonstrated the factors related to hookworm and O. viverrini infection, including primary school health programs, among secondary school students in Vientiane city of Laos. Material and methods: A cross-sectional survey and stool examination were conducted among secondary school students in Vientiane. One stool sample from each participant was examined using two Kato-Katz smears. Data of 164 participants were analyzed and the associations among parasitic infections, sociodemographic characteristics, and the school health program in primary school were assessed in a univariate logistic regression analysis. Predictors with p<0.25 were retained in a multivariate logistic regression model. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. The significance level was set at p<0.05. Results: The infection rates of O. viverrini and hookworm were 39.0% and 36.0%, respectively. Older students (OR=1.55, 95% CI: 1.01-2.37, p=0.046) and those whose father had irregular income (OR=0.47, 95% CI: 0.13-0.93, p=0.036) had a higher risk for hookworm infection. Students whose mother had irregular income (OR=0.30, 95% CI: 0.13-0.69, p=0.005) had a higher risk for O. viverrini infection. Higher primary school health program scores were associated with a lower risk for hookworm infection in the univariate model but not in the multivariate model. Conclusion: Sociodemographic factors have a strong influence on infections with both hookworm and O. viverrini. Current school health programs in Laos may be insufficient to reduce O. viverrini infections. Other approaches, such as supporting parents in finding employment with regular income, may be needed.