House modifications using insecticide-treated screening of eave and window as a vector control tool: evidence from a semi-field system in Tanzania and simulated epidemiological impact
8 affiliations
- 1Vector Control Product Testing Unit (VCPTU) Ifakara Health Institute, Environmental Health, and Ecological Sciences, P.O. Box 74, Bagamoyo, Tanzania
- 2Vector Biology Unit, Department of Epidemiology and Public Health, Swiss Tropical & Public Health Institute, Kreuzstrasse 2, Allschwill, 4123 Switzerland
- 3Faculty of Science, University of Basel, Petersplatz 1, Basel, 4001 Switzerland
- 4MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
- 5MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College, London, United Kingdom
- 6School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
- 7Vegro Aps, Copenhagen, Denmark
- 8VectorisIQ SARL, Montpellier, France
Abstract
Background: Gaps in unimproved house structures, especially in eaves and windows, allow mosquito entry, increasing indoor vector-borne disease transmission. Simple modifications to such houses may reduce human exposure, and insecticide treatment may kill mosquitoes, benefiting all community members. This study evaluated insecticide-treated screening (ITS) for eaves and windows, incorporated with deltamethrin and piperonyl butoxide (PBO), compared to a permethrin and PBO-treated bednet in Tanzania.
Method: A randomised Latin-square design (4 × 4) was used in four experimental huts within a large netting cage to allow mosquito recapture inside and outside of huts. Four treatments were evaluated: (1) new (12-month stored) ITS; (2) 12-month naturally-aged ITS; (3) 12-month field-used pyrethroid-PBO bednet (standard of care in Tanzania), and (4) no treatment. The study was performed for 32 nights using 30 mosquitoes per strain, per hut per night. Four laboratory-reared strains were used: malaria vectors (Anopheles arabiensis and An. funestus), dengue vector (Aedes aegypti), and nuisance biting (Culex quinquefasciatus). Recaptured mosquitoes were assessed for mortality at 72 h, blood-feeding, and hut entry. A simulation with a modified mechanistic model tracking Plasmodium falciparum malaria was used to illustrate potential epidemiological impact from these products.
Results: Against all mosquito species compared to 12-month aged pyrethroid-PBO-treated bednet, new ITS induced higher mortality [Odds Ratio:2.25(95%Confidence Interval:1.65–3.06),p < 0.0001], and aged-ITS was similar [OR:0.80(95%CI:0.59–1.08),p = 0.141]. Both new and aged ITS significantly (p < 0.0001) reduced mosquito blood-feeding [new OR:0.02(95% CI:0.01–0.03); aged OR:0.09(95%CI:0.05–0.14)] and hut entry [new IRR:0.10(95%CI:0.08–0.13); aged IRR:0.25(95%CI:0.21–0.31)]. Transmission model estimates indicate epidemiological impacts of ITS may supersede pyrethroid-PBO-treated bednets at the population level. The model results indicate impact potency depends on assumed intervention percentage cover, durability, and mosquito bionomics.
Conclusions: This study introduces a standardised semi-field bioassay to evaluate ITS, generating entomological data that, for the first time, enabled modelling of its potential impact on malaria transmission. ITS is an efficacious tool for public health as it kills substantial proportions of malaria and dengue vectors, and reduces nuisance biting. Given its simplicity, it should be considered an additional or stand-alone tool for screening unimproved houses.
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12889-026-28554-z.
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BibTeX
@article{odufuwa2026house,
title = {{House modifications using insecticide-treated screening of eave and window as a vector control tool: evidence from a semi-field system in Tanzania and simulated epidemiological impact}},
author = {Olukayode G. Odufuwa and Richard J. Sheppard and Safina Ngonyani and Ahmadi Bakari Mpelepele and Dickson Kobe and Agathus Njohole and Jason Moore and Jastin Lusoli Lusoli and Joseph B. Muganga and Rune Bosselmann and Ole Skovmand and Zawadi Mageni Mboma and Emmanuel Mbuba and Rose Philipo and Jennifer C Stevenson and Ellie Sherrard-Smith and John Bradley and Sarah Jane Moore},
journal = {BMC Public Health},
year = {2026},
month = jul,
doi = {10.1186/s12889-026-28554-z},
url = {https://doi.org/10.1186/s12889-026-28554-z},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - House modifications using insecticide-treated screening of eave and window as a vector control tool: evidence from a semi-field system in Tanzania and simulated epidemiological impact
AU - Olukayode G. Odufuwa
AU - Richard J. Sheppard
AU - Safina Ngonyani
AU - Ahmadi Bakari Mpelepele
AU - Dickson Kobe
AU - Agathus Njohole
AU - Jason Moore
AU - Jastin Lusoli Lusoli
AU - Joseph B. Muganga
AU - Rune Bosselmann
AU - Ole Skovmand
AU - Zawadi Mageni Mboma
AU - Emmanuel Mbuba
AU - Rose Philipo
AU - Jennifer C Stevenson
AU - Ellie Sherrard-Smith
AU - John Bradley
AU - Sarah Jane Moore
PY - 2026
DA - 2026/07/17
JO - BMC Public Health
DO - 10.1186/s12889-026-28554-z
UR - https://doi.org/10.1186/s12889-026-28554-z
AB - Background: Gaps in unimproved house structures, especially in eaves and windows, allow mosquito entry, increasing indoor vector-borne disease transmission. Simple modifications to such houses may reduce human exposure, and insecticide treatment may kill mosquitoes, benefiting all community members. This study evaluated insecticide-treated screening (ITS) for eaves and windows, incorporated with deltamethrin and piperonyl butoxide (PBO), compared to a permethrin and PBO-treated bednet in Tanzania. Method: A randomised Latin-square design (4 × 4) was used in four experimental huts within a large netting cage to allow mosquito recapture inside and outside of huts. Four treatments were evaluated: (1) new (12-month stored) ITS; (2) 12-month naturally-aged ITS; (3) 12-month field-used pyrethroid-PBO bednet (standard of care in Tanzania), and (4) no treatment. The study was performed for 32 nights using 30 mosquitoes per strain, per hut per night. Four laboratory-reared strains were used: malaria vectors (Anopheles arabiensis and An. funestus), dengue vector (Aedes aegypti), and nuisance biting (Culex quinquefasciatus). Recaptured mosquitoes were assessed for mortality at 72 h, blood-feeding, and hut entry. A simulation with a modified mechanistic model tracking Plasmodium falciparum malaria was used to illustrate potential epidemiological impact from these products. Results: Against all mosquito species compared to 12-month aged pyrethroid-PBO-treated bednet, new ITS induced higher mortality [Odds Ratio:2.25(95%Confidence Interval:1.65–3.06),p < 0.0001], and aged-ITS was similar [OR:0.80(95%CI:0.59–1.08),p = 0.141]. Both new and aged ITS significantly (p < 0.0001) reduced mosquito blood-feeding [new OR:0.02(95% CI:0.01–0.03); aged OR:0.09(95%CI:0.05–0.14)] and hut entry [new IRR:0.10(95%CI:0.08–0.13); aged IRR:0.25(95%CI:0.21–0.31)]. Transmission model estimates indicate epidemiological impacts of ITS may supersede pyrethroid-PBO-treated bednets at the population level. The model results indicate impact potency depends on assumed intervention percentage cover, durability, and mosquito bionomics. Conclusions: This study introduces a standardised semi-field bioassay to evaluate ITS, generating entomological data that, for the first time, enabled modelling of its potential impact on malaria transmission. ITS is an efficacious tool for public health as it kills substantial proportions of malaria and dengue vectors, and reduces nuisance biting. Given its simplicity, it should be considered an additional or stand-alone tool for screening unimproved houses. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12889-026-28554-z.
SN - 1471-2458
ER -