Resumen

MORENO, Jorge E et al. Preliminary evaluation of the effectiveness of Bacillus sphaericus in an malaria-endemic region in Bolívar state, Venezuela. Bol Mal Salud Amb [online]. 2014, vol.54, n.1, pp.47-57. ISSN 1690-4648.

The Sifontes municipality in Bolivar state is the principal malaria-endemic region in Venezuela. During the five years prior to the study an annual average of 14,000 cases was reported reaching an epidemic level of 19,408 cases in 2009. As part of the search for vector control measures that could be used as alternatives to insecticides, a commercial formulation of Bacillus sphaericus Neide (VectoLex^® CG 7.5%) was evaluated. Between May 2010 and May 2011 monthly dosages of 20-30 kg/ha of Vectolex were sprayed using a motorized backpack (Solo^®) in larval Anopheles darlingi, An. marajoara and An. nuneztovari habitats close to houses in four communities in the parish of San Isidro, Sifontes municipality. In parallel, adult anophelines were captured using human baits, CDC light traps and ultraviolet light traps. After 48 weeks of application there was an 80% reduction in malaria as well as a decrease in larval density demonstrating the effectiveness of B. sphaericus for the control of this disease. Moreover, the results suggest that larval prevalence is good indicator for biolarvicide based malaria control programs whereas the abundance of adults, which does not correlate with larval abundance, is not. This is the first time that the effectiveness of B. sphaericus for malaria control has been evaluated in Venezuela. These results show that spraying larval habitats for malaria control can be effective when integrated with other vector control strategies if the treatment is selective and carried out at the correct frequency and dosage in order to ensure adequate coverage of the larval habitat.

Palabras clave : Malaria; vector control; Anopheles darlingi; An. marajoara; An. nuneztovari; Bacillus sphaericus; Venezuela.

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