Health Argentina , La Rioja, Monday, January 18 of 2016, 11:26

Science and community united against Chagas disease

CONICET scientists work with the communities of Llanos del Sur of La Rioja to prevent infestation of houses by Triatoma infestans, aka “vinchucas” or conenose bugs

CONICET/DICYT David Eladio Gorla, CONICET principal researcher at the Instituto Multidisciplinario de Biología (IMBIV, CONICET-UNC) [Multidisciplinary Plant Biology], leads a research project funded by the Ministry of Science, Technology and Productive Innovation. The aim of the project is to measure the impact of the Programa de Erradicación de Ranchos promoted by the government of La Rioja – although it is linked to a national plan – about the infestation of triatoma infestans in the houses located in Llanos del Sur de La Rioja, an area identified as one of the most problematic ones in the cuyo region. What is new for this region is that with the training provided by the researchers, its inhabitants are in charge of survey tasks.


“In general, the personnel of the Provincial Programme of Chagas assess the houses or their peridomestic structures – corrals with animals or nearby depots adjacent to the family home – and following a series of established methodological guidelines seeks insects to determine if there is infestation of conenose bugs. The technique has low sensitivity, it is currently one of the best, and is standard in all Latin America. This time, we wanted to test a different method resorting to the work of the community, which has the advantage of mobilizing it to counteract health risks. We provided training in all houses; we explained to the inhabitants the objectives of the project and left them a plastic bag. After teaching to recognize the Triatoma infestans, we asked the people to use that bag to put the conenose bugs they found in their homes or in the peridomestic spaces”, Gorla explains.


The training with the families is completed with the scientists’ attendance at schools in the region, where they speak to the teachers and provide students with graphic material.

Two or three weeks after the first visit, the researchers go back to place to collect the bags, and talk to the inhabitants to see what is their perception regarding the problem. “This method allowed us to find conenose bugs in several houses, what would not have been possible with other techniques. This procedure has proved to be very useful”, the researcher states.


So far, 377 houses have been evaluated in San Martín, Rosario V. Peñaloza and Angel V. Peñaloza. Scientists found that 18 per cent of these places had conenose bugs inside the places where people live, even in the new houses and in some cases with established infestations that lasted for more than one year, due to the presence of immature stages of vinchucas. This situation highlights the need to conduct comprehensive community intervention, and not only give people a new home.


The research project led by Gorla has strong bonds with the Provincial Programme of Chagas. All the relevant information regarding the presence of vinchucas in the houses or peridomestic areas is sent to that programme. “We have good communication with the Chagas programme of La Rioja. Everytime we carry out an evaluation, we immediately provide them with the results so as to spray insecticide on the infested houses to prevent the risk of transmission of the parasite”, Gorla comments.


The research team led by Gorla, who was the director of the Centro Regional de Investigaciones Científicas y Transferencia Tecnológica (CRILAR, CONICET) [Regional Centre for Scientific Research and Technology Transference] in la Rioja from 2001 and 2013, works with the Programa Chagas La Rioja.


“We have worked with this programme for many years. Several studies we conducted resulted in developments that were incorporated. For instance, at one time, we promoted a geo-referenced information system that allowed us to twelve thousand geo-referenced rural homes in La Rioja. This is part of a database that helps to make better decisions regarding the way of distributing the resources”, Gorla comments.


For the researchers, although in La Rioja vectorial transmission of Chagas disease through vinchucas is currently suspended – what has promoted the improvement of the houses – is it necessary to implement an organized Entomological surveillance system capable of providing proper answers to avoid the risk of re-infestation of houses, specially in problematic areas such as the one of Llanos del Sur.