Controlling parasites, understanding practices: The biosocial complexity of a One Health intervention for neglected zoonotic helminths in northern Lao PDR

Abstract

A parasitological survey in northern Lao PDR showed a remote ethnic minority village to be hyper-endemic for Taenia solium, a Neglected Tropical Disease (NTD) that impacts human and pig health. An intervention combining human Mass Drug Administration (MDA) with porcine vaccination and antihelmintic treatment was then implemented, targeting both T. solium and other soil-transmitted helminths. To understand the biosocial complexity of this integrated One Health intervention, we conducted a rapid ethnographic study exploring the transmission dynamics of T. solium and locally acceptable long-term control options. Informed by two years of project work in the village, this included six focus group discussions, 35 semi-structured interviews, a latrine survey, a school-based education meeting, participant observation and many unstructured interviews conducted over two weeks in October 2013. We found that risk behaviours were mediated by various social determinants including limited market access, interrelationships between alcohol, ancestral sacrifices and the consumption of raw pork, seasonal variations and poor latrine coverage. Only sixteen percent of households had latrines, attributed to the unacceptability of dry latrines, lack of water access, poor building techniques and poverty. Whilst women could explain T. solium transmission, most men and children could not, revealing that distributed posters/leaflets relied too heavily on text and ambiguous images. Compliance with MDA was high due to trust between project staff and village leaders. However understandings of pharmacology, minor side effects, human migration and children's fear of worms may lead to resistance in future programmes. Our research highlights the complexities of controlling T. solium and other soil-transmitted helminths in a remote ethnic minority village and the need to integrate biomedical and participatory approaches. Although we showcase the heuristic value of using rapid ethnography to inform intervention strategies as part of a One Health/NTD agenda, we also identify several possible paradoxes and conundrums in embedding locally-grounded biosocial analysis into NTD programmes. These need to be acknowledged and negotiated by multidisciplinary teams.

Controlling Taenia solium and soil transmitted helminths in a northern Lao PDR village: Impact of a triple dose albendazole regime

“…[25,28]. These studies found that a single dose of albendazole 400mg had a cure rate of approximately 50% against Taenia with the relatively low levels of hygiene and sanitation as described by Bardosh et al [19], the potential for cysticercosis in this close living community is considered to be extremely high, further validating the suspicion that a large number of residents currently suffer from cysticercosis [18].…”

“…The village is homogenous for the Tai Dam ethnic group, an animistic culture which practises the consumption of raw pork associated with ancestral sacrificial ceremonies throughout the year [19]. Approximately 300 people (298 and 295 at the times of MDA) are dispersed amongst 60 households.…”

“…This research paper examines the impact of two albendazole triple dose regimes, undertaken five months apart, on the prevalences of T. solium and STHs within the target community, as determined by microscopy and PCR. The concurrent pig intervention is still ongoing and therefore not the focus of this paper, with the findings from the sociocultural work reported elsewhere [19].…”

Taenia solium Taeniasis and Cysticercosis in Southeast Asia

“…These include poor hygiene and sanitation practices such as open defecation, lack of health hardware such as functioning latrines, lack of access to clean water, lack of basic education and knowledge on disease transmission, feeding human waste to pigs, ancestral sacrifices and consumption of raw pork, and lack of meat inspection practices at slaughter houses. 14,29,33,34 In addition, household contacts may acquire the infection through direct or indirect contact with carrier's feces, and clustering of neurocysticercosis cases around carriers has been further identified. 14,35 There have also been reports suggesting a link between cysticercosis and the use of human feces and "wastewater" for fertilizing crops.…”

“…29,34,72 In addition, poverty and religious beliefs prevail people's unwillingness to discard or cook cyst-infected meat, particularly during sacrificial ceremonies in certain communities. 33 Moreover, instead of interrupting the disease transmission, meat inspection practices may counterintuitively produce a negative impact by contributing to further economic losses in pig farmers through stigmatization, thereby forcing them to avoid the regulated markets and sell at a cheaper price directly to the lowest income earners.…”