are in the MOST Phase I website (1994-2003).
The MOST Phase II website is available at: www.unesco.org/shs/most.
|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
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
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
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).
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
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
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.
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.
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
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
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
The practice is locally manageable.
Community health workers helped to provide local leadership, and local workers
were taught how to construct houses.
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
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
‘Healers of the Andes: Kallawaya Herbalists and their Use of Medicinal
‘The Kiss of Death. Chagas’ disease in the ‘Americas’, 1998.
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
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