Permethrin-impregnated mosqulito-nets effectiveness tested on experimental henhouses: preliminar study for prevention of Cutaneous Leishmaniasis in NE Argentina

MANTECA ACOSTA, M; ANDREA MASTRANGELO; NILSO MOLINA; OSCAR DANIEL SALOMÓN

Porto de Galinhas

Congreso; WorldLeish5; 2013

The use of insecticide-impregnated fabrics as preventive tools has become a relevant topic for research and control of vector borne diseases due to its effect decreasing vector-human contact, and the possibility to be applied at the local level with the active participation of communities. In this work we used non-commercial curtains since our objective is to find a participative control strategy where the own community can make and use the curtains. We impregnated them with permethrin because of its moderate volatility and toxicity in mammals, and for its high insecticide and repellent activity. The project is being developed in a rural area of Puerto Iguazú (Misiones, Argentina) where epidemic outbreaks of Cutaneous Leishmaniasis were reported in 2004-2005 with Nyssomya whitmani as incriminated vector. The objective of this work was to evaluate the changes of phlebotomine abundance in presence of 10% permethrine-impregnated mosquito-nets in semi-field conditions. We installed three experimental henhouses as phlebotomine capture stations in the border of the forest, leaving 50 meters between them. The treatment (impregnated curtain, IC) and controls (non-impregnated curtain, NIC; without curtain, WC) were assigned randomly. To simulate incomplete obstruction conditions of houses, curtains were set as to cover only two sides of the henhouse. During two consecutive nights, a light trap was set from 17 pm to 9 am to measure phlebotomine abundance. This design was repeated once per month from February 2012 to January 2013. In this preliminary analysis we used data from November, December and February analyzed with an ANOVA including ?night? as blocking factor. Autumn and winter months (April-June) were excluded because of low abundances registered in past studies.In the warm months sampled up to now we observed a significant difference in phlebotomine/trap/night abundance between treatments (F2,30=13.15, p=0.0001). Abundance in IC henhouses (25.65, SD 39.29) was lower than NIC (238.82, SD 476.21) and WC (453.43, SD 578.13). In these months, abundance decreased 89.26% in presence of an impregnated curtain compared to abundance in absence of curtain. In the remaining months (March, August, September, October) we found a similar trend but with greater variance of mean abundance within treatments. In the future we expect to build more complex models so as to evaluate the effectiveness of treatments considering daily and annual variation in phlebotomine abundance.