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International Development Research Centre (IDRC)
and LUDO Contenidos
Presents
Because of periodic dengue outbreaks in Cali,
dengue is on the City’s public and research agenda, and the public is also aware of the disease.
The Chaco region as a whole, not just the Bolivian part,
is considered one of the most endemic regions for Chagas disease.
One of the main problems in Peru is malaria.
Rice cultivation occupies an average of around 350,000 hectares
and the type of rice cultivation that uses flooding techniques encourages the breeding of the Anopheles albimanus mosquito.
Chagas disease in the Amazon behaves differently from the disease as it is classically known in the rest of Latin America.
Originally Chagas disease was a zoonosis, a disease from the forest,
but when the forest was destroyed the bug looked for another place to live.
The highest number of malaria cases
occurred in communities that had high rates of deforestation within a radius of 5 kilometres.
There are mega development projects in the area
that will greatly influence what will happen in the rest of the Amazon in the next 10 or 15 years.
BEYOND THE VECTOR Ecosystem approaches and vector borne diseases in Latin America and the Caribbean
To me, the ecosystem approach, or the holistic approach, means finding equilibrium with nature.
It is an approach that tries to go back to the origins of nature,
and tries to reach equilibrium between the plants, animals and humans that live there.
The traditional approach only gives the same answers.
We already know how transmission occurs, we all know that there is a mosquito.
The question is: Why can’t we control this disease?
Why can’t we use better and more effective strategies to prevent serious disease outbreaks and death?
The entomologist learns more about the socio-cultural aspects of the disease,
and the specialist in the socio-economic aspects learns about entomology
and this way they generate new ideas that go beyond their disciplines.
The integral and holistic logic of ecohealth permits the rational and hierarchical integration
of the different elements that affect the transmission of these diseases.
The information is shared, and already the biologist sounds like an agronomist and the agronomist sounds like a biologist.
Let’s leave aside the disease for a minute to think about health in general.
The consideration of socio-economic, physical-environmental and social organization elements, and the analysis of these spheres,
allows us to define the determinants of health. What determinines health rather than the disease?
This means working with the population, since they are the beneficiaries and users of the knowledge that we provide.
At the same time, the approach has a great capacity to identify which elements invite an intervention
in order to modify the disease’s transmission process.
Although the IDRC project involved various researchers from different areas in different countries,
there was excellent integration among the team.
Vectorial Reinfestation and Chagas Transmission in Rural Communities
The Chaco is an immense plain that extends into Argentina, Bolivia and Paraguay, with a great diversity of climates.
There is a large difference in temperature between the North and the South,
with maximum precipitation in the East, decreasing as you move to the West.
It has a diverse flora and fauna that have adapted to the heat and the little precipitation found in the region
Studies from the 1970s showed that the prevalence of Chagas was higher than 70% in the population.
More recent studies show that 40% of adolescents are infected.
This proves that the disease is not under control in this region.
There are various forms of transmitting the disease.
The transmission we typically study is associated with an insect and happens inside and around the home.
The insect, which feeds on the blood of mammals and birds, defecates on the person during feeding or immediately afterwards
and thus transmits the parasite.
We visited houses every 4 months to look for the insects and to spray the infected households.
Still we continued to encounter a high proportion of infected homes.
The main objective of the project was to find out if this reinfestation process
was due to problems in the application of pesticides and a repopulation of the Triatoma vector in the home
or if the reinfestation was caused by bug populations coming from outside the home and occupying these cracks.
Our work was not to fight against the bugs, but rather to work with the local population to understand and resolve a problem.
The bugs are in the wrong place, they are inside the homes,
and in order to understand this you have to speak with the inhabitants because people know where the bugs come from
and want to know what to do to prevent them from spreading in the house.
It is always important to ask, house by house, if there are any more bugs or if they are gone.
I think the health workers do their job well… I am happy because we are working on the problem.
We studied the entire community, not only each person but also the community’s customs and socio-economic factors
and we have been able to show that reinfestation is more likely in old homes than in new ones.
There are also more bugs in homes that are not plastered.
There is less reinfestation in homes where clothes are kept together in a designated space
compared with homes where people hang their clothes anywhere.
But what surprised us most was how few factors could be associated with the number of bugs
and this has to do with their adaptability.
Since the vector is pesticide resistant it can invade any house
without worrying for example about the type of wall, or the presence of clothing.
An Ecohealth Strategy for the Prevention and Control of Dengue in Cali
Cali is the third largest city in Colombia, and the largest city with a population at risk of contracting dengue.
There are currently 4 serotypes of the virus circulating, and 2 mosquito vectors at work.
The Aedes aegypti is the traditional vector and breeds mainly inside homes
but it has adapted well to breeding grounds in public spaces and non-optimal conditions, such as drains.
The city has 50,000 drains and the Secretary of Health applies larvicides throughout the city every 15 days
in order to prevent and control dengue.
At the same time, in the city’s growing unplanned areas where the vegetation and housing conditions are not optimal,
the imported vector, Aedes albopictus, is present and adapting to city conditions.
The risk of dengue, therefore, is understood as a complex systematic risk depending on many factors.
It needs to be approached in a transdisciplinary way
because it cannot be understood as an exclusively biological or immunological phenomenon, or by studying only the mosquitoes.
It is also important to take the urban development context into account,
as well as social and economic factors and the provision of services.
In order to get to know the characteristics of the neighbourhood where we were going to work, we inspected the sewage system.
The role of the social workers who worked on our project was to clarify what social conditions affect the prevention of dengue
and where it was important to intervene to control it.
After a year of research and uncovering information that provides us with an understanding of dengue transmission in Cali,
we created an intervention strategy with 4 main components.
This was coordinated with the community, decision makers and representatives from academia.
The first component has to do with the institutionalization of the dengue program.
The second is the educational component.
A didactic sequence was designed in order to change risk behaviours related to mosquito breeding grounds.
The third component has to do with communications.
And the fourth component is very important since it has to do with inter-sectoral work.
We designed a course in which community members and leaders, and public institution representatives participated.
We worked on 3 environmental problems in the area of Floralia,
where we had identified that possible and current dengue mosquito breeding grounds combined with pollution problems.
We conducted home visits.
This used to be full of debris, and it was impossible to walk down the street because the debris fell down towards the road.
And this is the site which was a dumping ground for debris and garbage only a few days ago.
With the help of the community, the Universidad del Valle and the Secretary of Public Health, it was possible to recover the area.
This does not end here because I want to keep going and see what other spaces can be recovered, not only those in my area.
There are a lot of degraded spaces and we can advise and help mobilize the community.
In the coming years we have to identify what monitoring strategies can be used during the inter-epidemic periods
in order to be able to anticipate these outbreaks.
We need to identify some factors that provide an early warning in order to prepare the services,
to intensify work with the community and, obviously, to be ready with a quick response when the outbreak begins,
rather than always putting out fires”..
Rice Irrigation Technique with Intermittent Dry Periods for Malaria Control
The worry in our country is that this vector, Anopheles albimanus, is now pesticide resistant.
Pesticides have been indiscriminately used in agriculture, and this has made the vector pesticide resistant.
So the country no longer has an alternative to control them.
This strategy specifically interrupts the biological cycle of the vector to allow us to control it and to reduce its density.
We aim to improve the quality of life of the locals because this strategy has other benefits too.
Intermittent irrigation, in Peru in particular, is very common in the entire coastal region.
What we have done is add obligatory dry periods into the process
in order to inhibit the development of the mosquito that transmits malaria.
These dry periods also reduce the number of diseases attacking the rice,
especially some specific plagues that strike during the first phase of crop development.
And at the same time, the use of smaller layers of water promotes greater clustering from the rice crop
which translates into increased yield.
We have promoted the creation of a platform where different institutions linked to this economic activity can participate.
With this type of project, we save water and we also control the malaria vector.
Farmers used to think that rice must have a 20 or 25 cm water layer continually,
so this new idea was a little difficult to understand.
I am a specialist in rice cultivation so for my part, I collaborated in the agricultural aspects of the cultivation.
But at the same time, biologists, entomologists, malaria specialists, doctors with malaria specialization,
and communications specialists have all taken part.
We have seen farmers who are not involved in the project
applying the technique after seeing the success of their neighbours.
I operate 24 hectares of land and during my first participation in the intermittent irrigation campaign in 2009- 2010,
we saved in terms of water, fumigations and fertilizers, and production improved by 15%,
while 70% of the mosquito plague was eliminated.
Water is saved, while chemical applications and weeds are reduced.
The mosquito population has declined by at least 70%, there are not as many mosquitoes as in the past.
Every day we visit the farmers and this is what they want,
to have constant support because we are always in competition with the commercial enterprises.
Since the project was run by professionals, I have not been scared, because I know that a professional will run things well.
This project has benefits wherever you look,
not only with regards to malaria but also in terms of improved yields,
and the reduced use of fumigation and chemical pesticides.
We would like this technique to be promoted in other rice regions in our country, and not only in our country
but also in other rice producing countries so they can learn about the results we have achieved.
The idea is that this experience can be extrapolated to other countries, because it has provided good results here.
However, it is necessary to validate the experience in each place
because every location is different and they do not have the same soils, climates,etc..
After testing it will work because with all of these benefits, the farmer will be able to accept, and adopt the technique.
The Ecosystem Approach and Chagas Disease Transmission in Ecuador's Amazon Region
In historically endemic regions, Chagas disease is related to the domestication of a vector
which systematically transmits the parasite within the home.
In the Amazon, we do not have vectors in the home,
but rather wild vectors which invade the home without colonizing it, but which produce continual transmission.
The most deforested areas are also the hottest and driest,
and these are the areas which have much more frequent transmission.
Transmission rate is higher and there is a greater number of cases in the areas with greater landscape degradation.
When we start working, especially in the diagnosis and in the active search for vectors in the homes,
we work with a group of 20 people.
Some biologists came and carried out the vector search in the forest community called Paco Cocha
located 3 hours from here on a difficult road, full of mud where you have to walk half an hour or an hour to reach each house.
Good afternoon, my name is Sara Peña, I work in the Ministry of Health.
The principal transmission factor that we observe is the presence of palm trees close to the homes.
In these deforested areas, there are few individual trees that accumulate a large quantity of mosquitoes.
Due to internal demographic pressure in the colonies, these mosquitoes must emigrate to look for blood,
and the open houses allow these insects to enter.
The community is gathered together to learn first what it is that the project will do and the expected results.
We are here to inform you a little about Chagas disease.
These awareness activities include sharing the research results with the community.
For example, who is infected, what to do in case of infection, how to obtain treatment every so often.
We have been able to show that the transmission of Trypanosoma Cruzi intensified
after petroleum industry activities started in the region.
This shows that the emergence of the disease is linked to the spatial occupation of the Amazon.
Principally, deforestation and the establishment of permeable homes surrounded by grasses
and isolated palms generated more intense transmission.
Malaria and Natural Resource Management in Ecuador's Amazon Region
Health policy in the region was defined at desks,
in the Ministry of Health in Quito, with models that are applied in all parts of the country.
We are therefore interested in learning about the malaria situation in the Amazon.
The State has not been able to integrate these poor people into their social policy.
In order for someone to gain access to a health professional, they have to first walk hours through the mud,
then they must travel by canoe, then they have to take public transportation,
and then many times when they reach the health service centre, the quality of the service is not good.
It is fundamental to reexamine policies on health services access,
including not only physical access but also cultural and economic access.
The objectives of this project are to look for quick malaria research methods:
to establish a malaria transmission model for the Ecuadorian Amazon:
to strengthen the existing research capacity in Ecuador including molecular techniques:
and to contribute to better malaria control techniques based on the results obtained in the research.
Therefore, we monitored 3 communities for a year.
We found that the 3 communities have different transmission models, with different species and different circumstances.
This reinforces the idea that we need to know about these realities
in order to build different control models for the different communities and realities.
Unlike in the rest of the country, the parasites in the region do not appear to be resistant to the medication
which means we can use medications which are much less expensive and more accessible.
It is interesting to see how the use of and closeness to the land
affect transmission in the mainly farming communities in the Amazon.
In Cofan Dureno, where there is no intensive use of the land, we encounter fewer cases of malaria.
The other important factor in transmission appears to be the working conditions in the petroleum wells.
The security guards go and spend hours upon hours in an uncovered area without any protection.
The other element that appears related is migration.
We are in a border area where there is an important conflict that causes a lot of migration.
It is fundamental to be able to work in a participative way.
The openness of local organizations and communities for health research is impressive.
The research process is a repetitive spiral.
So we have to go back to the beginning with these new hypotheses to prove if these really are the fundamental elements.
Malaria, Deforestation and Land Use Changes in the Guayana
The indigenous people told us that malaria was a health problem for them.
In April, in one week there were more than 1000 cases of malaria compared to an annual average of 250 cases.
This was because a new mining operation started in the area,
one of the last and most pristine corners of Venezuela, a practically untouched ecosystem.
People come from other malaria infected areas, such as Brazil and other mining areas in Venezuela.
They brought along the seeds for malaria to a place that had little or no malaria.
So we have had a huge explosion of the disease.
We chose 3 localities that are representative of the region and the region’s ethnicities – Criollos, Zanema and Yecuana -
and by studying the case history of the area,
we were able to see that only 6 communities contribute more than 54% of the malaria in the region.
One of the findings was that the main malaria vector, Anopheles darlingi, was found in all the communities where we worked,
as well as a high diversity of species, with 9 different species of Anopheles collected in total,
of which 3 have been involved in the transmission of malaria in Venezuela.
And of these we found the Anopheles darlingi to be positively infected with the malaria parasite.
What we have seen is that deforestation around communities introduces heterogeneity into the environment,
which invites different mosquitoes to colonize these sites,
so you are going to find more and a wider variety of mosquitoes.
We are creating an entomological monitoring network.
We have trained people to identify the mosquitoes and to collect them throughout the year,
so that these sites will be in some way strengthening the health system of the State of Bolivar.
- I am going to leave the battery, but I am only going to connect one side.
- And you connect the other at 6 pm.
We have been working with indigenous people in the region whom we have trained to prepare a weekly malaria report,
where, in addition to the parameters used by the Ministry of Health we include ethnicity,
because we noticed that the Zanema have more malaria cases than the Yecuana.
For us this strategic alliance with the communities is fundamental,
since there has to be total integration of what we do with their perception and their worldview of malaria.
Malaria is a perfectly preventable and controllable disease,
but achieving its elimination, will be very difficult in these remote areas.
We have the tools but we lack knowledge transfer and sufficient resources
to reach these poor, isolated and forgotten communities in very remote areas.
Vector Reinfestation Risk Management and Prevention of Chagas Disease
Guatemala was the first country to be declared free from Chagas transmitted by one of the vectors, Rodnius prolixus.
It has been very difficult for countries to eliminate this species.
Still, it can be eliminated with insecticides because it doesn’t live in the forest.
But our bug (Triatoma dimidiata) lives in the forest, it lives in caves and under rocks,
and every year it migrates to houses, attracted by the lights, and if conditions are adequate it reproduces there.
This means that if we continue spraying, we need to spray every year, and this is not what we want.
We want to prevent the bug from reproducing in the houses, even if it gets in.
The village of La Brea was selected because it had already been fumigated several times
and there have always been bugs inside the homes.
- Good afternoon. - Excuse me.
- Please come in. - How are you?
- Fine. - Nice to see you. How have you been?
The traditional construction model here is adobe, or mud,
and in general people build without windows so it is very dark inside the home.
The bugs love this darkness, the humidity, the lack of ventilation
and this is what we are trying to change, although without changing local culture.
If people do not want a window, there will be no window.
We want the house without cracks so that the bug cannot reproduce.
The engineers, who formed part of our multi-disciplinary group,
found that by mixing soil with sand in a certain proportion for plastering the wall, cracks can be avoided.
This is the most effective intervention because we know that spraying a house involves investing human resources, logistics,
and insecticides at a cost of approximately 1000 Quetzales per house.
Meanwhile a house improved like the one behind me, is an investment of roughly 250 Quetzales.
In this community we are working in a tripartite team: the Municipality’s health sector,
the University of San Carlos, and the community itself which contributes labour.
First we mix this earth with sand and then we soak it in the mud and we stick it on like this…
…with the hand.
The community itself does the work, and their job is to rework the walls and improve the floor.
What we do in collaboration with the Municipality is to find local materials and transport them to the communities.
First they wanted to see results so we made a model house.
When they saw the model house, and how easy it was to do, they wanted to replicate it.
As President of the community development council, in order to provide an example, I am doing my house over there,
in order to be an example for the community so that other people follow my lead.
The team members from the University guaranteed us that this floor has already been tested and it does not crack.
In order to plaster the wall, first we had to find out who did it, when they did it and why,
we had to do an anthropological study.
We found that it was the women who plastered, and it was done when there was little farm work
or when their family members were coming to visit. It is done for cosmetic reasons
but it is done every year. With the mixes that we are studying at the university, they will not have to replaster even after 5 years.
We are going to make the plaster, we are going to make 2 tins, and we are going to add one in of soil.
The engineers were in charge of studying the local materials in order to prepare a suitable formula to be used.
Then they taught the whole project team, the Ministry of Health representatives, the vector control specialists
and finally the community.
We try and prepare the community for when we will not be here so they can continue the work without us,
and so we look for people who can do this.
This is one of the rooms of my house, the walls are adobe.
Before the project, the walls were not improved in any way and there were many cracks where the bugs could hide.
When we came to this village there was a 35% rate of intra-domicile infestation and this rate has now dropped to 5%.
Women in Central America are very marginalized.
In general, they do not have an income and thus they are susceptible to a lot of manipulation,
and we try to free women a bit from this situation.
In one of the villages, the women themselves proposed building coffee nurseries,
and selling the coffee plants and managing the money themselves.
We only helped a little bit at the beginning by providing seed bags,
and now they are totally independent and sell the coffee special bags to be used as seedbags each year.
The chickens that used to be inside the house, are now kept in a chicken coop.
Keeping them in better conditions improves their production, and not only do community members eat more meat
but they can sell any surplus and this is money that the women earn.
Another aspect of keeping the animals outside is that Tripanosoma Cruzi does not reproduce in birds,
even though the bug is eating the birds’ blood,
it is not going to get infected with the Tripanosoma Cruzi which is the cause of Chagas disease.
The ecosystem approach means trying to live with the bug without getting sick.
Originally, the animals lived in the forest, the people in their villages
and transmission did not take place because we had good forests.
What we have to teach the people is to maintain an ecosystem like this, and to take good care of it,
so they can use it to collect wood, and so the animals can live there and bugs can live there,
so that they do not reach the houses.
The bug is in the forest and the people in their clean, well built homes.
We want people to live better. This is the holistic approach, development for health.
In June 2010 the intergovernmental initiative to control Chagas in Central America declared its support for the Ecohealth approach in the combat against the Triatoma Dimidiata, currently the most important Chagas vector in Central America.
In Peru, the Ministries of Agriculture and of Health have incorporated the irrigation with intermittent dry periods technique into their official policies.
In 2010, the new research teams continued their joint work with authorities and communities in order to facilitate the use of results in interventions and policies.
The initiative made an impact on the capacities of various researchers, professionals, technical staff and politicians. More than 30 students have developed their graduate thesis around the initiative, and 200 people have been trained in workshops and research techniques.
Twenty five scientific publications have been published or are being published and the results have been presented at more than 50 international events.
Research using innovative approaches contributed to improvements in the living conditions Latin America and the Caribbean’s vulnerable and poor populations.
This initiative received the technical cooperation of the Panamerican Health Organization, PAHO.