In recent years, there have been several epidemics of dengue in El Salvador. Control strategies have consisted mainly of blanket spraying neighborhoods with chemicals, which is costly and does not prevent the spread of dengue. The CHANGE Project has focused on developing cost-effective and community-oriented solutions for dengue control.

The CHANGE Project approach called Untadita [literally "a little dab"], supplied chlorine bleach treatment of water storage containers to control the dengue mosquito. By dabbing, mosquito eggs are killed before they hatch. The Untadita approach is based on the "NEPRAM" method (Negotiation of Improved Practices), which involves communities and health planners working together to develop effective and feasible behavior change interventions.

More than 3.5 million mosquito breeding sites were destroyed through the Untadita campaign. To reach this goal, radio spots, posters and stickers promoting the approach were produced. In addition, community volunteers, the army, national police, university and secondary students made house-to-house visits to negotiate the practice of the Untadita dengue control intervention.

Other alternatives to chemical control strategies are still being
investigated. In partnership with the Ministry of Health in El
Salvador, Cendepesca and the University of El Salvador, a study was done to determine whether a type of fish called Poecilia Sp. could feed on the larvae of the Aedes aegypti mosquito, the vector of the dengue virus in El Salvador. This type of fish was selected because it presents no ecological risk and because its predatory habits include a preference for the larvae of Aedes aegypti mosquitos.

Results of the study indicated, however, that if chlorine levels are at or above 0.6 mgL, there is 100% chance of mortality of the fish. This concentration of chlorine was average among water storage containers in urban homes. The study also found that the fish are sensitive to changes in temperature and that educating urban families about maintaining the fish would be difficult. Based on the research results, this option is no longer being considered for dengue control. The study is available in Spanish.