Indranil Acharya and Jayanti P Acharya
Malaria causes a lot of morbidity and mortality each year, esp. among troops operating in uncongenial Malarial areas. Personal protection by use of bed nets is one of the main methods of protection against the Anopheles and other species of mosquitoes, besides the anti-larval and anti-adult sprays. Insecticide-treated bed nets (ITNs) are already in use, but these involve periodic retreatment with costly chemicals. Long-lasting Insecticide-treated nets (LLINs) which do not require re-treatment, could therefore prove to be good substitutes for ITNs. A study was thus planned and undertaken to compare the efficacy of LLINs with ITNs, in an endemic area. The knock-down, effect after washes and repellant action of the LLINs were studied and analyzed. The results showed that LLINs were more effective in knocking down/killing mosquitoes as compared to the ITNs. Even after washes, the LLINs retained their initial level of effectiveness. In addition, they were more effective in reducing the Manhour Density (MHD) of the mosquitoes as compared to ITNs. The future of mosquito control largely depends on effective distribution, usage and retention of LLINs. More research and bio-efficacy evaluations are required especially to deal with factors like insecticide resistance.