Evaluation of a broadly-based control model of fascioliasis (liver fluke) in Central Vietnam

Fascioliasis (liver fluke) is listed as one of the most important parasitic infections in humans and animals in the developing world, posing a considerable burden to human public and veterinary health globally (Mas-Coma, 2005). In Vietnam, the prevalence of fascioliasis has increased rapidly since the beginning of the 21st century and it has become a zoonosis of great public health importance, with Central Vietnam being most severely hit by the disease (Trieu, 2011). The rising prevalence of the disease has been reported in all 15 regional provinces of Vietnam, increasing from 1,500 cases during 2004-2005 to 9,985 cases in 2011 (Nguyen, 2011). To date, comprehensive strategies for fascioliasis control are not in place, and the only control of the disease is reliance on chemotherapy with triclabendazole (TCZ), recommended by the WHO as the drug of choice for the treatment of both acute and chronic fascioliasis in humans (WHO, 2007b). However, TCZ resistance has been reported in animals and in humans (Ortiz, Scarcella, Cerna, Rosales, Cabrera, Guzman, Lamenza and Solana, 2013). Although alternative fascioliasis control measures are recommended elsewhere, no typical example has been proven to be effective in practice (Nithiuthai, Anantaphruti, Waikagul and Gajadhar, 2004; Saba and Korkmaz, 2005). Furthermore, various models of foodborne trematode infection control have been introduced and tested for their effectiveness but none of them are complete and applicable to all situations (Nguyen, Nguyen, Bui and Tran, 2011). In the context of the unavailability of effective control measures of fascioliasis, the study of a broadly-based control model of fascioliasis in Central Vietnam was conducted to address the burden of the disease and promote the community’s health. The model, selectively adapted from the trial control model of fascioliasis by Nguyen et al. (2011) and the intervention model by Molyneux (2006), comprised five main components: vector control, health education, improvement of local health systems, involvement of concerned bodies, and chemotherapy. This study aims to implement and evaluate a broadly-based control model for fascioliasis in a community with high prevalence of fascioliasis in Central Vietnam (1) to determine the seroprevalence of human fascioliasis by laboratory methods prior to the interventions; (2) to describe the risk factors associated with fascioliasis infections by conducting surveys on knowledge, attitudes and practices (KAP), and undertaking household observations and snail counts; (3) to report on the implementation of a broadly-based control model for fascioliasis infection; (4) to evaluate the effectiveness in reducing the seroprevalence of human fascioliasis of the broadly-based control model, comparing its impact with that of a model of treatment of humans and cattle alone, and to treatment of humans only; and (5) to explore the positive and negative factors that motivate or impede the successful implementation of the broadly-based control model for fascioliasis in Central Vietnam