Background: Soil-transmitted helminthiases (STH), which remain one of the most prevalent health problems in the world, are also present in a remote area of Thailand.
Objective: The present study aimed to determine the prevalence and risk factors of STH among Thai hill-tribe preschool-age children (PSAC) in a remote area of Thailand.
Materials and Methods: A cross-sectional study was conducted between November and December, 2013 in the Omkoi District of Chiang Mai province. The Thai hill-tribe PSAC were selected by a simple random sampling technique. A stool survey of children was conducted in nine child development centers using the formalin-ether concentration technique, and caregivers were interviewed regarding risk factors. A multiple logistic regression analysis was used to identify risk factors of STH among the Thai hill-tribe PSAC.
Results: A total of 282 children provided complete data. The study showed that 18.4% Thai hill-tribe PSAC were infected with one or more species of STH. Ascaris lumbricoides was the most prevalent STH (15.9%) followed by Trichuris trichiura (1.8%) and hookworm (1.1%), respectively. The significant protective factor of STH among Thai hill-tribe PSAC was ownership of a latrine (AOR = 0.3, p = 0.04).
Conclusion: The present study showed that STH is a public health problem among Thai hill-tribe PSAC in the study area. Deworming of preschool children is warranted. Preventive measures should address important factor, and a health educational programme regarding the construction of latrines is an essential elements to prevent re-infection.

Keywords: Soil-transmitted helminthiases, Ascaris lumbricoides, Preschool-age children, Hill-tribe group, Risk factors