Neglected tropical diseases

Thailand uses integrated ecosystems health approach to beat cancer-causing disease

15 December 2017 | Geneva –– The pain grew from worse to intense. At one point it became so bad that Surawat, a fisherman and head of a family of four, could hardly lift a straw broom. After protracted episodes of acute abdominal pain, Surawat’s wife decided to take him to the nearest health clinic of the village in Chonnabot District (Khon Kaen Province) – although distance always deterred Surawat.

Health clinic in Chonnabot District (Khon Kaen Province)

On examination, the doctor ordered stool tests and imaging of the abdomen. The diagnosis was clear: Surawat was suffering from a foodborne infection caused by the parasite Opisthorchiasis viverrini1 (opisthorchiasis) - adult flukes that live in the bile ducts. The infection, if left untreated, can cause cancer of the liver.

Surawat was lucky. His condition was treatable. He was prescribed 25 milligram-praziquantel tablets and had to take them three times a day for three consecutive days. The doctor explained to Surawat and his wife that eating traditional raw fish (koi pla2) could be one of the major reasons for his infection.

Opisthorchiasis in Thailand was widespread about 60 years ago. With the implementation of a national programme and along with rapid industrialization and urbanization, including changes in life-style and food habits, the prevalence of O. viverrini infection decreased considerably.

But the scenario remains different in rural north-eastern Thailand, where many people still live off traditional agriculture and fisheries and where opisthorchiasis remains an important public health problem. For the government, it was clear that previous control strategies had sustainably decreased the level of infection in this part of the country.

Ecosystems approach

In 2008 the WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian liver fluke disease) at Khon Kaen University in discussion with Thai authorities introduced the EcoHealth/One Health approach – known as the Lawa Lake Project – an integrated eco-systems approach3 involving a multi-sectoral, multi-disciplinary, community-based control model, with a focus on school children and education for awareness. Among other materials, local health officials have also introduced a school curriculum of colourful cartoons that aim to teach children about the risks of consuming raw foods.

The approach is innovative and rests on active participation and community action,” said Professor Banchob Sripa of the WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian liver fluke disease). “It is integrative and transdisciplinary and uses an ecosystem approach to health, including human behaviour and the social ecological aspects of food processing, preparation and eating fish preparations”.

The approach has contrasted with past conventional “top-down” medical and public health interventions programmes which Thailand carried in the past, focusing on treatment alone.

There have been a number of different initiatives over the years that focused on health promotion, awareness campaigns, and education campaigns on “safe cooking”, among others, with support from different organizations besides the Ministry of Health: the United States Agency for International Development (USAID), the German Society for International Cooperation (GTZ) and Mahidol University of Thailand.

Results

The results of the Lawa Lake project have been outstanding: the prevalence of liver fluke infection in Lawa village declined from 67% to 16% over three years with minimal re-infection (Sripa et al, 20154).

The success was a result of not only access to medicines, treatments and ecosystem monitoring but most importantly of innovative education methods and tools to generate awareness about transmission of liver fluke and on sustainable and eco-friendly tools to prevent infection in the communities.

The strength of the Lawa project, which makes this initiative worth implementing in other areas and countries, is its multiple components to control foodborne diseases:

  • Manual of liver fluke control strategies: Development of a manual on liver fluke control, to guide the community-based activities and school initiatives, as well as the hospital awareness campaigns.
  • Technical training for liver fluke control: Development of specific training on liver fluke for hospital staff and volunteers. These trainings prepare them to monitor and report cases and prepare health recommendations accordingly to the communities.
  • Community-based treatment and intensive education: Special treatment programmes with intensive education, targeting different age groups including not only children but also adults, and utilizing media and technological tools to get better reach and engage communities.
  • School-based information, education and communication and science curriculum: Liver fluke disease was incorporated in the science curriculum at local schools to expand the impact of the awareness campaigns through children.
  • Disease surveillance and environmental monitoring: Programmes that strengthen surveillance and monitoring are crucial to measure and help estimate the prevalence and burden of liver fluke disease, as well as contributing to research in which environmental conditions favour the infection or presence of the trematode.
©Prof Banchob Sripa of the WHO Collaborating Centre for Research and Control of Opisthorchiasis

Success and hope

The success of the project has gone beyond the initially selected villages and has now expanded to the whole country with a focus on rural and high prevalence areas, and internationally to neighbouring countries.

The Lawa project has also become a model of how to address foodborne disease control activities and programmes. It harmonizes efforts of different stakeholders to avoid duplication and provides a bottom-up approach with a focus on disease awareness and education. Part of the education campaign focuses on getting people to use proper toilets, and avoid defecating in the lake, which reduces the number of fluke eggs.

The burden of opisthorchiasis has decreased in the past few years in Thailand as a result of the collective efforts of the Lawa Project, public initiatives and other activities, but significant efforts are still required.

As he suffered from opisthorchiasis, Surawat knows that more knowledge and awareness of this liver fluke infection and its link with liver cancer should be disseminated.

Today, he and his wife volunteer with health workers and regularly go around talking to fellow villagers of his rice-growing neighbourhood, mainly to get people to change their eating habits, by cooking koi pla to kill the flukes before they eat it.

Surawat hopes this will make a difference in a country well known for and proud of its cherished local dishes and recipes that have been passed down through generations.

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1O. viverrini has been classified as a Group 1 carcinogen (metazoan parasites that are carcinogenic to humans) by the International Agency for Research on Cancer, WHO. It is considered the major etiological agent of bile duct cancer, cholangiocarcinoma.
2Koi pla is a traditional dish of raw fish, ground with spices and lime. It is eaten by millions of Thais, especially in the north-east of the country.
3Integrated control methods involving a combination of technologies and expertise from different fields beyond biomedicine or conventional public health, including those from social, environmental and ecological sciences.
4Sripa B et al. Toward Integrated opisthorchiasis control in northeast Thailand: the Lawa Project. Acta Trop. 2015; 141(Pt B):361–7. doi:10.1016/j.actatropica.2014.07.017.


Contact:
Ashok Moloo
WHO/HTM/NTD
Telephone: +41 22 791 16 37
Mobile phone: +41 79 540 50 86
molooa@who.int
@ntdworld

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