National Program of Opisthorchiasis in Thailand; Situation and Policy Strategy

Abstract

Opisthorchiasisis, a chronic parasitic inflammatory disease of the bile ducts, caused by liver fluke or Opisthorchis viverrini infections is a crucial significant public health problem in Thailand. Most evidence of Opisthorchiasis is reported from national programs. Thus the magnitude of liver fluke infection at the national level required to assess the effectiveness of the national opisthorchiasis control program. In Thailand, infections with Opisthorchis viverrini are associated with a high mortality secondary to Cholangiocarcinoma (CCA). A systematic countrywide national survey in Thailand already reported from the past more than half-century (59 years) in 1957 to date in 2019, revealed the declining trend of the overall helminthiasis infection from 62.9% (in 1957) to 8.13% (in 2009). The National Opisthorchiasis control program managers have initiated and established a national plan to prevent and control these eradicate diseases through the interaction and responses of the provincial public health sectors.  However, the national control program managers need to have information determined by evidence-based needs. These intensive data are representative of all ages of the population of Thailand and are derived from the national household survey. The national prevalence of Opisthorchis viverrini in this study was carried out in 77 provinces.  A total of 9,904 samples of stool specimens were obtained from the population by using a cluster random sampling under WHO guidelines.   The results of this large scale survey showed that the overall prevalence of Opisthorchaisis among Thai people was 4.0%.  The highest prevalence of O. viverrini was 11.9 %, in the health region 5 in the Northeast region. During this national survey of Opisthorchiasis, geographic information is also conducted to investigate the prevalence of O. viverrini. The spatial analysis would be the trends and analyze the risk factors that correlate with infections among rural Thai people. The recommendation that already showed the impact of National program useful for every country especially in Mae King basin for elimination and control for opisthorchiasis.