Comparison Study Of Effectiveness Of Long Lasting Insecticidal Nets By Who Cone And Standard Who Tube

Objective: To compare effectiveness of long lasting insecticidal nets by WHO conetest and standard WHO tube testMethods：WHO cones test and standard WHO tube test were employed to evaluatethe used LLINs collected from target villages covered by free distribution ofPermaNet2.0long lasting insecticidal nets from Global Fund malaria project. Thenumber of mosquito Knock down within60min and mosquito death within24hoursand were observed and the mortality were compared.Results: After Anopheles dirus exposure to positive PermaNet2.0, the mortalitywithin24hours was94.20%and89.60%by WHO cones test and standard WHO tubetest. The mean knock rates within60minutes were both100%. The mortality within24hours by WHO cones test is34.95%、27.84%、27.39%、26.06%among washing5,10,15and20times. There are difference statistically （χ2＝239.74，P＜0.05）among4group bednets. The more washing, The lower mortality（chi square for trendχ2＝49.16，P＜0.05）. The mortality within24hours by standard WHO tube test is60.38%、50.09%、36.72%、27.92%among washing5,10,15and20times. There aredifference statistically （χ2＝609.35，P＜0.05）among4group bednets. The morewashing, The lower mortality（chi square for trendχ2＝259.10，P＜0.05）. The meanknock rate within60minutes by WHO cones test is87.57%、88.63%、86.09%、72.52%. The more washing, The lower knock rate（chi square for trendχ2＝26.41，P ＜0.05）. The mean knock rate within60minutes by standard WHO tube test is98.74%、99.12%、96.90%、95.58%. The more washing, The lower knock rate（chisquare for trendχ2＝17.16，P＜0.05）.There is statistically no different mortalitybetween WHO cones test and standard WHO tube test （χ2=0.77，P=0.37）. Theknock rates by WHO cones test and standard WHO tube test are all100%. Themortality and knock rates by WHO cones test and standard WHO tube test amongwashing5,10,15,20are difference statistically.Conclusions: Although the mortality within24hours and knock rates within60minutes by WHO cones test and standard WHO tube test are different amongwashing5,10,15,20times bednet group, Insecticidal effectiveness of PermaNet2.0present the downward trend after more washes.