Review and Current Status of Opisthorchis viverrini Infection at the Community Level in Thailand

Opisthorchis viverrini is remains a public health problem in Thailand, particularly in the northeast andnorth regions which have the highest incidences of chonalgiocarcinoma (CCA). O. viverrini causes the diseaseopithorchiasis, and its has been classified as a group 1 biological carcinogen. Humans, dogs, and cats becomeinfected with O. viverrini by ingesting raw or undercooked fish containing infective metacercariae. The firsthuman cases of O. viverrini infection were reported in Thailand 100 years ago, and it’s still a problem at thecommunity level. Based on data for the year 2009, more than 6 million people were infected with O. viverrini.Associated medical care and loss of wages in Thailand costs about $120 million annually. This review highlightsthe current status of O. viverrini infection in communities of Thailand through active surveillance for the fiveyears period from 2010 and 2015. A total of 17 community-based surveys were conducted, most in the northeastregion. Some 7 surveys demonstrated a high prevalence over 20%, and the highest was 45.7%. Most commonlyinfection was found in age group of 35 years and older, males, and agricultural workers. Although, the nationalprevalence may be decreasing but the results show that the O. viverrini infection is still high in communities ofthe northeast region. Therefore, the focus in populations living in northeast Thailand should be screening ofinfection and changing their eating behavior.