Application of Climate-Driven Model on the Risk of Opisthorchis viverrini Infection in Thailand

摘要

Opisthorchis viverrini (0. viverrini), known as a small liver fluke, is a parasite that lives in the bile duct of the mammals including humans. Opisthorchiasis caused by O. viverrini infection is a major public health in many countries in Southeast Asia including Thailand and significantly associated with the development of cholangiocarcinoma (bile duct cancer). Environmental factors, particularly climate, significantly influence the life-cycle of O. viverrini as well as its intermediate host snails. The climatic parameters such as soil moisture, temperature, and precipitation may alter the geographical distribution of O. viverrini by affecting the suitability of freshwater bodies for hosting both parasite and snail populations. Thus, opisthorchiasis is expected to respond to the climate change. However, the influences of climate on the incidence and distribution of opisthorchiasis in Thailand has not yet been addressed. This study aimed to investigate the interaction between climate and opisthorchiasis levels in Thailand using the climate-driven disease model. The climate data and the prevalence of O. viverrini infection in 2009 were obtained from the Thai Meteorological Department and Department of Disease Control, Ministry of Public Health, respectively. The risk maps illustrated that the risks of opisthorchiasis in the North and Northeastern regions were found in May, June, July, and September with the highest overall predicted risk being in July. The climate-driven risks of opisthorchiasis in July are consistent with the risks determined from the observed prevalence of O. viverrini infection using hot spot analysis. With that, this model can be used to forecast both area and timeframe of opisthorchiasis at the local scale, which can be used to support health planning for implementation of disease prevention and control strategies.