PREVALENCE AND ASSOCIATED RISK FACTORS OF INTESTINAL PARASITES IN HUMANS AND DOMESTIC ANIMALS ACROSS BORDERS OF THAILAND AND LAO PDR: FOCUS ON HOOKWORM AND THREADWORM.

Hookworm and threadworm infections are major public health problems in developing countries. A cross sectional study comprising 843 participants (346 males and 497 females) was conducted in three populations: i) Thai residents (TR) of Ubon Ratchathani Province, Thailand; ii) Laotian immigrant workers (LI) in the same province; and iii) Laotian residents (LR) in Champasak Province, Lao PDR. Participants were interviewed based on a structured questionnaire regarding their health status. Stool samples from participants and 300 samples from domestic animals (277 dogs and 23 cats) living in the participants households were collected and examined for parasitic infection using a formalin-ether concentration and a Harada-Mori filter paper culture techniques. Approximately one-third of TR and LI populations and domestic animals in Thailand were positive for parasitic infections, while almost half of LR population and domestic animals were positive. We confirmed by PCR and DNA sequencing a case of Ancylostoma ceylanicum infection in a Thai man. We also observed infections of other parasites, such as Taenia spp and Opisthorchis viverrini. Multivariate analysis indicated that risk factors for hookworm infection were population group and walking barefoot. Factors associated with threadworm infection were population group, adult male, lack of previous antiparasitic treatment and of knowledge of parasitic infection, and failure to wash hands after contact with domestic animals. Our results highlight the high prevalence of both hookworm and threadworm infections especially among LI population and domestic animals in both countries. Our findings emphasize the need for public health intervention to control the spread of parasitic infections in Thailand and Lao PDR.