Chagas' Disease: Prevention, Southern Cone Initiative

In 1991-92 the "Southern Cone Initiative" project was launched by Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay, with the objective of stopping the transmission of Chagas’ disease. In 1997 Peru joined the project. After an initial phase for preparation (charting the foci, programming the activities, calculating the costs), there was an attack phase with insecticides, repeated after 3 to 6 months. Insecticide-containing paint is cheaper than the traditional insecticides which are applied by spraying. Insecticides dispersed by fumigant canisters were also used. These are locally produced, e.g. in Argentina, are cheap, effective and also active against Aedes aegypti, the important dengue vector. At present there are effective colourless long acting insecticides. The fact that people see the bugs, cockroaches, etc. lying dead after spraying, is a bonus which makes it easier to accept the spraying procedure. In the Southern Cone Initiative, 1,800,000 houses were treated with pyrethroids (deltametrine, lambda-cyhalotrine, cyflutrine) by the year 2000.




Since then there has been further selective treatment of the houses which still exhibited infestation with triatomes. Simple "sensor boxes" of cardboard (traps for the bugs) were placed in the rooms and the occupants themselves could simply ascertain the presence of triatomes. The last phase is surveillance for the detection of residual foci. This is decentralised and involves the population. The effectiveness of the control programme has been demonstrated by the very pronounced drop in seropositivity among young children. The surveillance phase has been reached in 6 countries of the Southern Cone. At present there are several South American countries (Colombia, Ecuador, Venezuela) which have a national control programme. Similar programmes were begun in Central America in 1997: Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Mexico and Panama. These programmes can only be successful if there is participation of the population and if they can be continued for long enough. The latter is a political decision.

Category: Medicine Notes