Helminth infections and associated risk factors among adults in the Lao People’s Democratic Republic

Abstract Background Helminthiases are highly endemic in Southeast Asia including the Lao People's Democratic Republic (Lao PDR). This study aimed to assess the current helminth infections prevalence among adults across Lao PDR and the associated risk factors. Methods A cross-sectional survey was conducted in 165 villages across 17 provinces and the Vientiane Capital, Lao PDR. A multi-stage sampling method was employed to select the adult study participants (≥ 18 years). Data collection followed the World Health Organization’s stepwise approach, which includes (i) the interview of the study participants, (ii) the physical assessments, and (iii) the stool sample collection. Analysis included the description of socio-demographic characteristics and infection status of helminth infections. Logistic regressions were applied to test the association between helminth infections and individual risk factors. A P-value below 0.05 was considered statistically significant. Results From 2,800 enrolled study participants, 57.8% were female. Average age was 45.4 years. Fecal analysis detected Opisthorchis viverrini in 18.8%, hookworm in 21.6% Strongyloides in 4.8%, Ascaris lumbricoides in 2.3%, Trichuris trichiura in 1.5% of and Taenia sp. in 3.3% of study participants. O. viverrini was of high prevalence in the southern (28.8%) and central (21.3%), while hookworm (26.3%), A. lumbricoides (7.3%), T. trichiura (3.1%), and Taenia spp. (4.2%) were prevalent in the northern provinces. Multiple logistic regression analysis showed that males were more likely to be infected with hookworm (adjusted odds ratio [aOR] = 1.2; 95% confidence interval [CI]: 1.1–1.4). The Lao-Tai ethnic group had a 5.2-times (95% CI: 4.6–5.8) higher chance of having O. viverrini infections than the minorities. Possession of the toilet facility at home prevented helminth infections, e.g., O. viverrini (aOR = 0.4, 95% CI: 0.3–0.5), hookworm (aOR = 0.6, 95% CI: 0.5–0.7), S. stercoralis (aOR = 0.6, 95% CI: 0.5–0.7), A. lumbricoides (aOR = 0.7, 95% CI: 0.6–0.8), T. trichiura (aOR = 0.7, 95% CI: 0.6–0.8), and Taenia spp. (aOR = 0.5, 95% CI: 0.4–0.7). Conclusions Our study provides the first nationwide assessment of intestinal helminth infection among adults in Lao PDR. It provides critical information for guidance to the national helminth control program in Lao PDR.