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Best Practices on Indigenous Knowledge MOST/NUFFIC (IK-Unit)


Control of Chagas’ disease through a Cultural Context Model: Proyecto Britanico Cardenal Maurer in Sucre, Bolivia



Community health, education, housing construction, hygiene, insecticides, insects, medicinal plants, plant products, training


Introducing the practice

The practice has been used among Aymara and Quechua speakers in the Andean regions of Peru, Bolivia, Chile, and Argentina. The aim was to devise a culturally sensitive approach to teaching people how to improve their houses so as to prevent Chagas’ disease. The project reported here, which was based in Sucre, Bolivia, was carried out in the department of Chuquisaca between 1989 and 1997. It involved year-round activities.

Through the project, a method was developed for teaching peasants about how triatomine insects—popularly known in Spanish as vinchucas—carry and transfer the parasite responsible for Chagas’ disease. The peasants are then taught how to build or improve their houses to make them vinchuca-free.

90% of all houses in the region are infested with vinchucas. Between 60 and 80% of all vinchucas carry T. Cruz, the deadly parasite that causes Chagas’ disease. ‘Chagas’ produces a higher rate of DALY (disability-adjusted life years) than any other disease in Latin America. It disables workers in the prime of life, often killing them. Many widows and orphans are thus left behind with no source of income.

The practice is still in use. Since it employs native personnel and resources that are locally available, the practice is sustainable. It is in fact held up as a model for other projects (see Bastien 1998).

The practice did not originate within the community. It began in 1989 when the British Embassy began to collaborate with Ruth Sensano, the director of Proyecto Britanico Cardenal Maurer (PBCM).

The project developed an approach based on existing (global) disease control knowledge (improvement of housing is the most cost-effective way to control the disease) combined with local, indigenous knowledge on construction.


Content and approach

Ruth Sensano worked with a training team consisting of two traveling doctors and a number of technicians (specialized in building, spraying, and epidemiology) and nurses. In the communities, the team worked with local community health workers.

Each community selected a community health worker to be responsible for educating the people, organizing the villagers, and coordinating interaction with the PBCM team. Approximately 80 small communities were involved, each with an estimated 40 to 200 families. Responsibilities were equally divided between men and women. Children were taught about the disease and its causes and prevention through school plays (they portrayed insects and were driven out of houses) and through dances, songs, and educational material. An important element in the project was that schoolchildren passed on to their parents what they had learned about the dangers of the vinchuca. Because housing and housing hygiene are culturally sensitive subjects and vary from one region to the next, it was essential that a culturally sensitive model be used to educate the peasants involved (see Bastien 1998).

The process

PBCM selected four communities to serve as examples. Their success attracted the interest of subsequent communities. The method is as follows:

·           Each community elects from among its adult members someone to be the community health worker. ‘Chagas’ control is one of this person’s responsibilities.

·           The community health workers receive three two-week training courses in applied public health and in how to collaborate with the PBCM team.

·           At joint meetings, the community health workers are taught extensively about parasites, insects, and how houses can harbour disease. They are given posters, comic books, and other educational material that will help them in turn to educate the rest of the community.

·           A member of the PBCM team visits each community for one week, during which time he or she meets with the community health worker and the village leaders, who in turn hold meetings with the adult members of the community until consensus has been reached, the necessary tools and materials have been assembled, and everyone has agreed to do the necessary work.

·           Each village receives matching resources which have been donated by the UK, USAID, and the Chuquisaca Diocese.

·           PBCM sends bricklayers to show the villagers how to make their houses vinchuca-proof.

·           Existing houses are examined before and after improvement. New houses are monitored on a monthly basis.


Housing improvement to reduce infestation

House Improvement Committees (HIC) are the functional units where plans and priorities for housing improvements are decided and where all participatory activities are coordinated. HIC consist of a president and secretary who are responsible for organizing work groups of five to six villagers. The Committees coordinate tasks with members of the community. The groups are assigned different tasks and are supervised by a master craftsman who teaches members basic carpentry, how to lay foundations, tile making, and plastering. Local materials and personnel are used whenever possible. HICs and craftsmen supervise and coordinate the repair and/or construction of houses. They work between the months of May and September, when agricultural work is least demanding and community members are most available.

By way of illustration: in Sucre, Bolivia, for the Proyecto Britanico Cardenal Maurer (PBCM), villagers worked to compensate for roughly half the cost of a house improvement (USD 75.00 per house) and provided supplies worth USD 18.75; PBCM contributed supplies, fumigation, education, and supervision to the value of USD 114.00. Each improved house costs USD 208.00, with villagers providing 45 % and the project the remaining 55 %. Not counting free labour, the project improved a house for USD 114.00 and its total budget was USD 45,614 for 400 houses.

House improvement consists of putting in a solid concrete foundation that does not crack, plastering the internal and external adobe walls to cover existing cracks, whitewashing the walls with lime, installing glass windows and metal screening, tiling the roof, and installing a ceiling in the interior. Bedrooms are first improved, followed by dining and storage rooms. Depending on the condition of their houses, some families may decide to demolish and reconstruct them, sometimes adding additional rooms, especially bedrooms. These improvements eliminate common nesting areas for triatomines. PBCM allotted supplies progressively in order to provide an incentive to complete each task and receive the next supply, thus removing the temptation to misallocate the materials. Households prefer to do the most desirable tasks first and neglect the less desirable, such as improving the surrounding area.

One criticism of PBCM was that, in the first 400 houses, it did not improve peridomicile areas and, when they were evaluated, vinchucas were found in these areas. Subsequently, bug-proofing of peridomicile regions became part of the programme. The better strategy is to start with the peridomicile and, once this is improved, supply materials for the house. This ensures both corrals and house are bug-proofed.

Traditional methods and available resources are used alongside more innovative techniques, tools, and materials whenever possible. Sand, earth, and cow dung are collected locally to make wall plaster. Dung serves as an insecticide when mixed with earth and lime into plaster. Workers prepare the lime by heating locally collected limestone rocks in an open kiln for twenty-four hours and then pulverizing the residue with a hammer. After plastering, they apply a white paste of lime and water to the walls to improve the appearance. Wall plastering substantially reduces vinchuca infestation, but to be successful it has to be done thoroughly, so as to seal all the cracks and crevices in the house walls. The use of slow-release insecticide paints is another preventative measure. Villagers can be taught to make ceramic tile roofs to replace thatched roofs, greatly reducing a popular infestation area for triatomines. One community in Bolivia mastered tile making and began marketing their tiles to neighbouring villages, thus developing a small local industry. Low-cost roofing material is needed in developing countries to provide a substitute for corrugated galvanized iron roofing, which is very noisy when it rains and heats up when it is hot, both common conditions in the tropics. Sheet roofing, with its sharp edges, is also extremely dangerous in windy climates when it becomes stripped from the house and is sent hurtling through the air.

A stable concrete house foundation is necessary for each house to prevent water damage to the base of the walls and floor. Cement is expensive in terms of both price and transport costs, but a durable local substitute material can often be used. Soil stabilization can also be achieved by increasing the cohesion of the soil (this is one area where technical assistance is helpful). As an alternative, the mechanical compaction of adobe mix greatly increases its stability. An adobe press with a long handle used as a lever to compress the mud and clay in molds provides more leverage than chest and arm muscles and results in a much harder adobe.


The role of indigenous knowledge

Indigenous knowledge (IK) played a role in many ways. Importantly, most of the community health workers were also their village’s traditional medical practitioner. Traditional knowledge of building houses served as the basis for the improvements. The local people already knew that applying dung to plaster walls killed vinchucas, for example. IK was also involved in the planning of houses. The local herbalist knew that eucalyptus and certain other plants killed insects. The local people already knew how to mix adobe that would not crack. And finally, indigenous rituals were practised before the houses were built so that Pachamama would not be offended, and prayers were said to keep out vinchucas.

Andeans do not take to the outright spray-and-kill techniques generally used by outsiders. This often involves DDT, and beneficial insects are also killed off indiscriminately. The alternative is to practise housing hygiene, which is a very difficult concept even in European countries. But Andeans took to the idea that vinchucas rob them of sleep and blood, so why not keep them out. User-friendly insecticides were suggested, and a layer of cow dung beneath the plaster helped to keep the insects out. Moreover, the positive effects seen in new houses helped to overcome many obstacles.

Use of local herbs

Local herbs are used in several ways to treat the symptoms of Chagas’ disease. For the treatment of constipation and the accompanying gastric pain, such as that caused by megacolon in Chagas’ disease, or even for congestive heart failure, the Kallawayas of Midwestern Bolivia were using guayusa (Ilex guayusa), a holly-like shrub, and sayre (Tabucum rustica) with an enema syringe to purge patients as early as A.D. 400. Sniffing tobacco and guayusa not only cleanses the passageways by causing sneezing, tobacco also stimulates the cardiovascular system when nicotine enters the bloodstream. Thus some of the debilitating effects of chronic Chagas’ disease are meliorated. Even today, Kallawayas claim that wild tobacco is an effective vermifuge and parasiticide. The Andean pharmacopoeia features potent parasiticides and vermifuges because of selective aspects or uses of certain plants able to kill predatory organisms. Native plants provide insecticides for eliminating vinchuca bugs (Triatoma infestans), carriers of the Chagas parasite (Trypanosoma cruzi). Compounds including ruda (rue, Ruta chalapensis), ajenjo (absinthe, Artemisia absinthum), andres waylla (Cestrum mathewsi), and  jaya pichana (Schurria octoarustica) are experimentally proven insecticides. Bolivians have learned this and use large quantities of these plants. They cut them into small pieces, smash them, and boil them in water. This is then mixed with dirt and used to fill holes in the adobe to kill infesting vinchucas. Another method used is to pound small rocks into the holes of the adobe. Plaster is mixed with coca, an excellent insecticide, and fleshy parts of prickly pear cactus (Penca de Tuna or Opuntia ficus indica) to form glue that helps the plaster stick to the adobe. A compound called el paraiso, made from muña (Satureja boliviana), is used to kill potato worms and has been suggested for vinchucas. Peasants also use spiders and carpinteros (small household lizards) to rid their houses of vinchucas. The plant  floripondio (Datura sanguinea) gives off a nightly fragrance that discourages vinchucas from entering the house around which it is planted. Eucalyptus leaves burned inside the house in the evening have a similar effect. These native remedies and insecticides are all relatively safe and environmentally sound, something that cannot be said for pharmaceutical drugs and commercial insecticides.

Chilean scientists have been testing Kallawaya medicinal plants for the treatment of Chagas’ disease. Several of the plants appear to help in curing Chagas’ disease. Herbalists in Bolivia regularly use plant extracts with indole alkaloids, which suggest the possibility of medicinal effectiveness without excessive toxicity. Various tropical plant species used by tribal groups contain beta-Carboline alkaloids, and scientists at the University of California, Irvine, tested them and found that they reduce population growth of T. cruzi epimastigote forms. Native herbalists can help in identifying potentially effective drugs from natural sources. Using native lore can reduce the number of empirical tests often conducted on natural plant products. Plant products provide an alternative to toxic synthetic drugs and indicate potentially active structures for chemists interested in synthetic molecular modification.

Bolivian herbal doctor Nicolas Carrasco claims to have cured patients of Chagas’ disease with a herbal remedy called  ‘Regenerator’. Carrasco learned a cure from curanderos about the medicinal qualities of a resin from the fruit of the Rotan palm tree (Calamus drago), called Sangre de Drago (Blood of the Dragon). The plant’s seeds are toasted, crushed, added to a small glass of pisco liquor, and drunk daily. This purges the body of toxic fluids, changing cold and wet blood into hot and dry. According to Andean ethnophysiology, it accelerates centrifugal forces in the body. The seeds can be crushed, making a salve that relieves rheumatism. The active ingredients in fresh seeds are acetic acid (like vinegar), butyric acid (like arnica oil), glyceride (like soap), and castor oil, which form a powerful purgative. This is effective against the constipation sometimes caused by the infestation of T. cruzi parasites in the lining of the lower intestine, thus inhibiting sphincter muscles from contracting and expanding to remove faeces.

A contemporaneous Bolivian herbalist, Jaime Zalles treats chagasic heart disease with three flowers of retama (Spartum junceum) in a maté (steeped in hot water), with two leaves of cedron (Lippia triphylla). The ingredients serve as a tranquilliser for heart attack victims. Toronjil Melissa officinalis L. is also used for heart problems associated with ‘Chagas’. Carrasco’s and Zalles’ cures have not been validated by biomedicine.

Andean traditional medicine provides treatments for Chagas’ disease as well as insecticides that may even be better than the present products produced by pharmaceutical and chemical companies. Western biomedicine does not have an effective cure for chronic Chagas’ disease. Presently, the two prescription drugs used for treating it are nifurtimox (produced by Bayer, recently discontinued) and benznidazole (Roche), used for acute and chronic phases. Bolivians find both costly, unsatisfactory, and painful, and many prefer to go to native herbalists for a cure.

The complexity of Chagas’ disease has been addressed by Andean culture in a number of ways. Andeans deal with its symptoms through rituals, community concern, and herbal medicines. Curanderos have combined forces with doctors to combat or adapt to T. cruzi. They appear to have dealt with Chagas’ disease as adequately as biomedicine. Even if this is not so, the possibility necessitates much closer examination of ethnomedical systems for solutions to endemic disease throughout the world. Andean rituals also provide a great service to medical science by indicating the interrelatedness of Chagas’ disease and the environment, showing the reciprocal relationship between the human body and the earth and its organisms.

Transmission of new knowledge

At the start of the project, the community members did all the construction work themselves, but they turned out to be insufficiently skilled. Eventually trained builders were brought in and the villagers provided unskilled labour, carrying sacks, preparing materials and cleaning up. But in all cases one or two community members learned the skills, thus ensuring the project’s sustainability. One community learned how to make roof tiles and eventually sold tiles to other communities.

Community health workers from all over the province met every month. Whenever a project was completed, the local community health worker invited the others to come and see. Word about the new houses spread. The knowledge has also been documented (see for instance Bastien 1998), and video films and posters about the project have been produced.

Community participation

Project success and sustainability are a function of community participation and indigenous knowledge. As illustrated above, peasants have many adaptive and effective ways to solve their problems. It is important that they take primary responsibility for resolving their problems with the assistance and expertise of NGOs and government workers. Community participation is more cost-effective than purely structured programmes. Housing projects are more readily integrated into other programmes if there is community participation: active rather than passive involvement, with people making their own decisions and carrying them out. Community participation involves community members making decisions about, accepting, and complying with certain behavioural changes necessary for combating Chagas’ disease. These include plastering cracks in the walls, keeping animals outside, and storing objects in containers to keep vinchucas from infesting the house.

Problems relating to community participation include the absence of skilled local labour for some tasks. There may be limited cooperation among households because of their distance from each other. Some peasants refuse to cooperate for one reason or another. Certain adults refuse to work with other adults. Poor sanitary conditions persist in many areas. Peasants also have other tasks they consider more necessary, such as planting and harvesting crops. These problems in part indicate a lack of understanding of sociocultural issues and limited skills in cross-cultural communication from project works and NGOs. NGOs sometimes confuse the idea of community participation when they imply that they have the solution to the problem. Technicians should endeavour to educate and activate peasants to participate in finding a solution. They should esteem their indigenous knowledge and use it to remove vinchucas and to treat Chagas’ disease, for which there is no known biomedical cure. Cross-cultural community participation (CCCP) involves lengthy discussions with all members of the community (including women and children). CCCP has no have simple answers for the prevention of Chagas’ disease; it allows people to arrive at solutions after they have been presented with the facts in terms that are meaningful to them. It involves serious discussion as to why peasants behave as they do. Why, for example, do they keep animals in the house? If this is not seriously considered, they will continue to do so no matter how nice their new house. This has been the experience of the housing project in Tarija. CCCP demands that technicians negotiate change only after extensive discussion has taken place and understanding has been achieved about values and why people do what they do. CCCP is a pedagogy based upon an epistemology of exchange: knowledge is mutually arrived at between interested parties. This is essential in the case of Chagas’ disease, principally because of its social and cultural complexity that affords no unilineal or vertical approach.


Achievements and results

The project produced significant results. PBCM improved 452 houses between 1987 and 1991, another 400 in 1992, and by 1997 it had improved 2,600 houses. PBCM improved the first 453 houses with a budget of USD 83,256. The community itself had contributed almost half of this amount (USD 37,642). Ruth Sensano predicts that by the year 2005 the project will have improved another 2500 houses—provided, that is, that it receives assistance from the municipalities. Since new laws were enacted in Bolivia in 1994, the municipalities receive tax revenue for the purpose of regional improvement.

The practice of training peasants to rid their houses of the insects that transmit Chagas’ disease is sustainable. Sustainability is guaranteed because an epidemiologist periodically checks the vinchuca infestation rate within each community, and then helps to determine what needs to be done. The community health workers play a crucial role by coordinating activity between community members and the PBCM team. Proyecto Britanico is no longer involved in the practice but Cardinal Maurer and Ruth Sensano still are.

The practice is cost-effective. PBCM started out with modest funding before USAID entered the picture. Houses were built for a little over USD 100 each. This meant substantial housing improvement at very low cost. USAID saw this as a successful project, well worth a large contribution. This had some drawbacks because USAID wanted fast results that it could present in its reports. Cultural sensitivity declined as the concern for accountability increased.

The practice is locally manageable. Community health workers helped to provide local leadership, and local workers were taught how to construct houses.

Strengths, weaknesses, and room for improvement

One strength lies in the fact that the community health workers are elected for terms of only two years, and they may be re-elected only once. This prevents anyone from holding on to the office and removing it from the bi-annual electoral process. The community takes responsibility for this person. The community health workers organized themselves as groups of practitioners independent of the biomedical profession. This gave them the autonomy to administer their own medicines and traditional forms of treatment while at the same time acting as liaisons with practitioners of biomedicine.

The biggest weakness was that the community health workers sometimes left the group of traditional practitioners to become doctors and nurses. Or they remained in office too long and thus became members of the establishment themselves—either the community establishment or the Ministry of Rural Health. This meant that the community lost control over them. Another weakness was that some of the community health workers began giving injections haphazardly. Andeans have become addicted to the ‘magic bullet’. This would not have happened if the diagram for a Culture Context Model had been followed. (See Bastien 1998, which also offers suggestions for improving the PBCM project.)

The practice could be improved by blending it with other indigenous knowledge. There should be more supplies of medicinal plants in the regional pharmacies. In addition to the herbal manuals already published, there is a need for study of Kallawaya medicinal plants and their pharmacological uses.

Community health workers should be given more recognition for the work they do as midwives, yatiris, and curanderos in clinics and hospitals. The significant role they play in public health should be properly recompensed.


Source of inspiration

The practice can be replicated anywhere in the world where people are living in unhealthy houses. As long as the Culture Context Model is used (see Bastien 1998: 134-157), the practice could easily be transferred to other groups, cultures and land-use systems.

The community health worker project has already been replicated throughout Bolivia, and communities all over Bolivia, Chile and Peru have adopted similar programmes. The suggestions offered in ‘The Kiss of Death’ (Bastien 1998) have been incorporated into projects throughout Latin America. A community health worker project in the Department of Oruro, Bolivia, is just one example.

The project offers a model for how other regions or countries could tackle the disease in an economic, cost-efficient and effective way. The case certainly provides input for policy-making processes.

If you think that this case could be useful in a different context than the one described here, please get in touch first with the contact person listed below (Administrative data). Intellectual property rights could be an issue.


Additional remarks and information

Bastien, J.W.

·           ‘Healers of the Andes: Kallawaya Herbalists and their Use of Medicinal Plants’, 1987.

·           ‘The Kiss of Death. Chagas’ disease in the ‘Americas’, 1998.


Administrative data

Person(s) who have described this Best Practice

Joseph Bastien, Ph.D.

Director of Anthropology

Department of Anthropology and Sociology

Box 19599 University of Texas at Arlington

Arlington, Texas 76019

E-mail: bastien@uta.edu



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