This study examined the durability and insecticidal efficacy of long-lasting insecticidal nets (LLINs) distributed three years prior in five Afghan provinces. Interviews with 500 households found high LLIN survivorship of 87.7% but 19.6% lacked enough nets. Physical inspections found 65% of nets in good condition and 32% acceptable. However, cone bioassays found the nets did not meet WHO criteria for insecticidal activity and wireball assays just met the 80% threshold. Chemical analysis found the deltamethrin level was only 15.1% of the reference value. The results have implications for future LLIN procurement and replacement strategies in Afghanistan.

1. Durability and Efficacy of Long Lasting Insecticidal Nets
(LLINs) distributed three years ago in five provinces
(Nangarhar, Balkh, Hirat, Kunduz and Khost) of
Afghanistan
Study report
Final version
Date: May 01, 2015

2. HealthNet-TPO – Report Durability/efficacy study of LLINs distributed in 2011 in Afghanistan– 2015
2/2
Summary
Background: Inthe past7 yearsmore than 9 millionLong-LastingInsecticidal Nets(LLINs) have been
distributedinmalariaendemicprovincesinAfghanistan.Onaglobal level,thereislimitedknowledgeabout
the life spanof LLINs infieldconditions.Thisisthe firststudyinAfghanistan,inwhichthe durabilityand
insecticidal activityof LLINsissystematicallyexamined,aftertheyhave beenusedinAfghanhouseholdsfor
a periodof three years.
Methods:500 householdsin5malariaendemicprovincesinAfghanistan(Nangarhar,Khost,Hirat,
Balkhand Kunduz) thathad receivedLLINsthree yearsearlierwere selectedthroughclustersampling.All
householdownerswere interviewedaboutsurvivorship,use andmaintenance of theirLLINsandthe
available LLINswere inspectedforholes.Fromeachhouseholdone LLIN wasrandomlyselectedandthen
transportedtothe Jalalabadentomologylaboratory,where theywere rigorouslyinspectedtocalculate
theirproportionate Hole Index.Fourpiecesfrom200 randomlyselectedLLINs(40per province) also
underwentcone bioassaytestingandwireball assaytestinginthe Jalalabadentomologylab.Five pieces
from40 randomlyselectedLLINs(8perprovince) were senttoanexternal laboratoryforHPLCinsecticide
contenttesting.
Results:Our studyfounda relativelyhighoverallLLIN survivorship(87.7%) of the LLINsdistributedin
2011 and a highLLIN utilizationrate inthe hotseason.AttritioninNangarharprovince wasrelativelylow,
while LLIN utilizationwasrelativelyhighincomparisonwiththe otherprovinces,probablybecause of the
highermalariaburdeninthatprovince.Worryingly,19.6% of the householdshadtoofew LLINsforall
householdmemberstosleepunder.Also,large proportionsof LLIN ownerspractice harmful LLIN washing
procedures.
Physical durabilityof 500 randomlyselectedLLINs(measuredwiththe proportionateHole Index) was
still relativegood,with65%of the LLINsin a goodcondition,32% of the LLINs inan acceptable condition
and 3% of the LLINsbeing‘tootorn’.
Contrarily, our sample of LLINs did not meet the minimum WHOPES criteria for cone bioassay
insecticidal activity testing after three year of usage. Only in the 60 minute wireball assay tests our tested
LLIN sample just scored above the 80% cut-off value. The mean Deltamethrin concentration in the LLIN
sample (0.2711 g/kg netting material) was only 15.1% of the Deltamethrin reference value (1.8 g/kg netting
material).
Conclusions: The implications of our insecticidal activity tests results for future LLIN replacement and
procurement activities in Afghanistan need to be further discussed by (inter)national malaria experts. Next
to that, more attention should be given to proper LLIN washing practices and to alternative channels for
households to get extra LLINsin between LLIN distribution campaigns. Further research needs to be done in
the country on (critical factors affecting) LLIN durability and efficacy and on effective LLIN replacement
strategies.