Fabric integrity, net type and risk index predicts attrition of insecticide-treated nets: evidence from a community durability trial of piperonyl butoxide (PBO) nets in Tanzania
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Date
2025-11-26
Journal Title
Journal ISSN
Volume Title
Publisher
Malaria Journal
Abstract
The fabric integrity of insecticide-treated nets (ITNs) deteriorates over time during household use,
often leading households to discard or stop using damaged nets. This study quantified the extent
to which net loss from households is attributable to declining fabric integrity, accounting for
variation in user behaviour and environmental conditions.
Methods
This secondary analysis used data from an ITN durability trial in Bagamoyo, Tanzania. A total of
2,514 ITNs (three pyrethroid-PBO and one pyrethroid-only) distributed among 1,509 households
were included because they had the outcome of interest (attrition). Fabric integrity was classified
as good, damaged, or too-torn according to WHO ITN guidelines and assessed at 12-month
intervals. The association between fabric integrity and net attrition over the subsequent 12 months
was evaluated using an adjusted logistic regression model, accounting for net type, household risk
index, household size, and age of the household head as fixed effects, with household as a random
effect.
Results
Attrition increased over time, from 20% at one year to 53% at two years, and 83% at three years
post-distribution, and it was associated with net type, household risk index, household size, and
age of the household head. Damaged ITNs at one year were more likely to be lost by year two.
Compared to nets in good condition, damaged nets had higher odds of attrition (OR: 1.73, 95%
CI: 1.06-2.82), and too-torn nets were at greater risk (OR: 9.82, 95% CI: 5.87-16.4). Similar
patterns were observed between years two and three (damaged: OR =1.55, 95% CI: 0.83-2.90; too-
torn: OR=11.7, 95% CI: 6.16-22.3).ACCEPTED MANUSCRIPTARTICLE IN PRESS
ARTICLE IN PRESSConclusion
Fabric integrity was the main driver of rapid ITN attrition and the strongest predictor of loss.
Damaged nets were approximately twice as likely to be discarded after one year and at least ten
times more likely to be lost in years two and three. These findings highlight the importance of
promoting proper net care practices and procuring durable nets that withstand harsh household
conditions, ensuring sustained population coverage.
Sustainable Development Goals
2: Zero Hunger
3: Good Health and Well-being
11: Sustainable Cities and Communities
Keywords
Insecticide-treated nets: ITN: fabric integrity: attrition: piperonyl butoxide: household risk index: Tanzania