The Socioeconomic Burden of Cholangiocarcinoma Associated With Opisthorchis viverrini Sensu Lato Infection in Northeast Thailand: A Preliminary Analysis.

The northeast of Thailand, which is the poorest region of the country, has the highest incidence of cholangiocarcinoma (CCA) worldwide. This is associated with infection with the liver fluke Opisthorchis viverrini. Although an estimated 20,000 people die every year of this disease, the socioeconomic impact of this mortality on the victims' family and the community in which he or she lived remains unknown. Here, we provide background information on the socioeconomic groups most effected by CCA and provide a qualitative estimate of the likely financial burden on the family and community. Most victims of CCA are small-scale farmers. Mortality occurs most commonly in males between the ages of 40 and 65, having either children or grandchildren to support. Costs can be divided between premortality with the family paying for transport and accommodation to the hospital, as well as costs not covered by the Thai Universal Health Coverage scheme. The main costs, however, are likely to be postmortem with loss of income and potentially the loss of a major contributor to farm work. What is urgently required is a quantitative estimate of the costs of CCA and long-term studies of the families and communities affected to determine where and how the burden of CCA falls.

Cost comparison of rapid questionnaire screening for individuals at risk of clonorchiasis in low- and high-prevalence communities in northern Vietnam.

Clonorchiasis is an emerging food-borne trematode infection in Vietnam. Due to the absence of cost-effective preventive measures its control largely relies on morbidity reduction by chemotherapy with praziquantel. We performed a comparative cost estimation of three different diagnostic and intervention approaches in areas of high and low prevalence of clonorchiasis in northern Vietnam in order to select more cost-effective chemotherapy. Our study confirmed that a questionnaire investigating the habit of eating raw, freshwater fish was a rapid, cost-effective and operationally feasible tool for identifying individuals at risk of clonorchiasis in both high-prevalence and low-prevalence areas. The cost of diagnosis and intervention per person and per true positive case was 20-fold higher in low-prevalence areas, regardless of the type of approach. Geographical mapping of high-risk areas prior to screening is, therefore, recommended to maximize the cost-effectiveness of the intervention activities.

Opisthorchis viverrini: an underestimated parasite in world health.

Infection with Opisthorchis viverrini and its associated cholangiocarcinoma (CCA) is an underestimated problem in the Mekong region of Southeast Asia, despite the widespread use of praziquantel and health education measures for parasite control. Although data from Cambodia, Laos and Vietnam are rare, data from Thailand often show wide-ranging variability in epidemiological parameters, including human morbidity and the prevalence and incidence of CCA. The recent discovery of high levels of population genetic variability in O. viverrini in different wetlands in Thailand and Laos, which indicates the presence of sibling species, suggests that we have underestimated the complexity of this epidemiological situation. Future research should determine the relationship between the genetic variability of O. viverrini and patterns of opisthorchiasis-related disease.

Preliminary estimates of economic impact of liver fluke infection in Thailand and the feasibility of irradiation as a control measure.

Liver fluke infection by Opisthorchis viverrini is the leading cause of food-borne parasitic disease in Thailand. Approximately one third of the population in the northeastern region of the country, ie, 6-7 million, are infected by this parasite through the habit of consuming raw or insufficiently cooked freshwater fish, especially those of cyprinoid family. A recent survey showed that 60% of the work force in the Northeast between the age of 15 and 60 is infected. The estimated wage loss of this population may be approximately Baht 1,620 million (US$65 million) per annum. The estimated direct cost of medical care may be as high as Baht 495 million (US$19.4 million) per annum. Thus, the total direct cost of the infected work force is estimated to be Baht 2115 million (US$84.6 million) per annum. Irradiation of fish flesh infected by metacercaria of O. viverrini has been demonstrated as an effective method of control. A minimum dose of 0.1 kGy is effective without changing physiochemical properties of the fish flesh. This technology, therefore, shows promise as a method to control infection by O. viverrini acquired by the habit of consuming raw freshwater fish in the country. Preliminary economic analyses indicate that the public health benefit from preventing infection with this parasite could outweigh the investment cost of irradiation facilities. Detailed economic feasibility studies should be carried out to demonstrate the practical efficacy and cost-effectiveness of the treatment as a public health intervention measure in the country.