Effectiveness Of Long-lasting Insecticidal Nets Evaluated By Channel Test

Objective:To evaluate effectiveness of long-lasting insecticidal nets (LLINs) by tunnel test for the protection of vulnerable populations in malaria endemic areas to provide scientific evidences.Methods:Tunnel test was employed to evaluate the used LLINs collected from target villages covered by free distribution of LLINs(PermaNet"2.0) from Global Fund malaria project. The number of death mosquito,30min Knock down,survival mosquito and blood feeding were observed. The mortality and blood-feeding rate were compared.Results:The average crossing rate of Anopheles minimus during 30 minutes exposure to PermaNet(?)2.0 was 3.4%,2.8%,5.3%,4.6% among new nets,0,5,20 washes of LLINs. The average mosquito knockdown rates were 7.8%,7.8%,5.7%, 8.2%during 30 minutes exposure among new nets,0,5,20 washes of LLINs. The mortality rate of Anopheles minimus after exposure was 92.4%, 91.7%,87.2%,89.0% among new nets,0,5,20 washes of LLINs respectively. The blood-feeding rate of Anopheles minimus after exposure was 0.3%, 1.5%,1.3%,2.1%among new nets,0,5,20 washes of LLINs respectively. The survival rate of Anopheles minimus after 24 hours recover was 38.6%,59.2%,62.2%,70.2% among new nets,0,5,20 washes of LLINs, respectively. There was statistical difference among the survival rate of new nets, 0,5,20 washes of LLINs (χ2= 290.52, P<0.05). The total mortality rate of Anopheles minimus was 97.1%,95.1%,92.1%,92.3% among new nets,0,5,20 washes of LLINs, respectively. There was statistical difference among the total mortality of new nets,0,5,20 washes of LLINs (χ2= 2.345, P<0.05). The total mortality was decline among new nets,0,5,20 washes of LLINs (chi square for trendχ2=5.79, P<0.05)Conclusions:Effectiveness of PermaNet(?)2.0 affected by washing during the usage of local resident in malaria endemic areas of Yunnan. Insecticidal effectiveness of PermaNet(?)2.0 present the downward trend after more washes.