Working group: social, epidemiological, and control determinants of Chagas disease in American Southern Cone

Abstract

Discussion was opened with the aim to contributewith the ALCUEH net work in preparation of a basis fortraining, divulgation, and definition of national policiesconcerning neglected diseases, in the context of South-ern Cone Initiative for Chagas Disease (INCOSUR).The first presentation (Joao Carlos Pinto Dias) sum-marized the most important historical and political an-tecedents of the initiative, as well as its most recent ad-vances and principal challenges in the new millennium.JR Coura - Starts the discussion asking the partici-pants to focus their interventions in the three main pur-poses of the meeting, such as: (a) the neglected and oremergent aspects of the disease, requiring additionalinformation to improve the pertinent political action; (b)the main projects for control qualifying and technologi-cal transfer; and (c) the regional details for each par-ticular project. As an specific question, ask the partici-pants their opinion about what to do with the othertriatominae species in the Region, following the elimi-nation of Triatoma infestans.A Rojas de Arias - Giving her thanks for the invita-tion and nomination, she remembers that INCOSUR –besides its general and epidemiological purposes, hasadditionally the task for being an example and a modelfor similar initiatives in the whole region.AC Silveira - Remembers that the secondary and na-tive species cannot be eliminated, so obliging us to livetogether with them, looking for a situation of low den-sity and no colonization. The strategy will be a continu-ous and strict surveillance, in all endemic areas, focusedin the determination of the main risk factors for thevectoral Chagas disease transmission, such as the infes-tation degree, the colonization capacity, and the antro-pophilic characteristic of each species. Finally, pointsout that, in Brazil, the most important species in the ar-eas where T. infestans has been eliminated areT. brasiliensis, T. pseudomaculata, T. sordida, and Pans-trongylus megistus.R Zeledon - Agreeing with JC Pinto Dias exposition,reinforces its political aspects and launches two generaland one technical questions: (a) since the vector elimi-nation represents a political question and consideringthat in general political actions are discontinuous andnot stable, is it really the elimination an attainable goal?(b) What can be made to reinforce the political decisionof national governments, so avoiding the loosing of theprimary objectives? (c) Is it possible that residual Tri-atominae populations recover the initial scenery of hous-ing infestation?AC Silveira (answering Dr Zeledon) - It is very dif-ficult the recovery of controlled Triatominae popula-tions, specially in the case of T. infestans and after theconclusion of chemical attack phase. This recovery isgenerally too slow and the regular surveillance actionsgenerally avoid indoors reinfestation. In Southern Conemost of T. infestans residual foci are peridomestic andthe few and scarce sylvatic foci of this species seem torepresent no significant danger for housing colonization.To sustain an effective surveillance it is required a goodand fast feed back capacity in a local and decentralizedhealth system, monitored and supported by national andregional health unities. A very frequent and preoccupantgap in such an approach consists in the insufficient and fewtrained local teams, with the lack of regional supervision.AR Prata - Three main questions arise from this sub-ject: (a) the need to insist in the elimination of otherspecies strictly domiciliated, as the case of P. megistusin great part of Bahia, Brazil; (b) to maintain the regularepidemiological surveillance against the peridomesticspecies, looking for their withdrawal of indoors spaceas great as possible; (c) the need to keep in mind that thepresent success of control programs will certainly to befollowed by several difficulties to maintain the priorityfor the control action.Prof. Prata still considered that the priorities in Cha-gas disease tend to go down. Nevertheless, epidemio-logical surveillance will be required for a long time, be-ing necessary to maintain it, as it has been done for thecases of the plague and yellow fever. He remembers thatin the past several rationalities were invoked to impedethe starting of regular programs, including in Brazil. Forinstance, interminable academic discussions were car-ried on, concerning the options between housing im-provement and chemical fight for vector control. By an-other angle, chiefly in situations of decentralization,other priorities and problems of the local communitiesuse to result in governmental deviations from the Chagasdisease program objectives. It is the case, for instance,of several epidemics of dengue fever in Brazil, requir-ing human resources and even insecticides which fre-