Evidence map›Paper›PMID 41972098›Full record

ArticleGates open research2026

The mini chamber test: a novel bioassay for bioefficacy testing of chlorfenapyr treated nets used in malaria control.

Amy Lewis, Rowan Jones-Brown, Gemma Harvey, Giorgio Praulins, Emma Reid, Aidi Galus Lugenge, Frank Mechan, Katherine Gleave, Rosemary Susan Lees

Abstract read
In one paragraph

Article in Gates open research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Amy LewisLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.ORCID https://orcid.org/0009-0003-4846-2335
Rowan Jones-BrownLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.
Gemma HarveyLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.
Giorgio PraulinsLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.ORCID https://orcid.org/0000-0003-2601-2598
Emma ReidLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.
Aidi Galus LugengeIfakara Health Institute, Bagamoyo, P.O Box 74, Tanzania.
Frank MechanLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.
Katherine GleaveLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.
Rosemary Susan LeesLiverpool School of Tropical Medicine, Liverpool, England, L3 5QA, UK.ORCID https://orcid.org/0000-0002-4232-9125

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Dual-active-ingredient insecticide-treated nets (Dual-AI ITNs) combining pyrethroids with chlorfenapyr are increasingly being deployed across malaria-endemic areas. Laboratory evaluation of chlorfenapyr ITNs is challenging due to chlorfenapyr's requirement for metabolic activation. Inspired by the tunnel test, the mini chamber test is smaller, has higher throughput, and is animal-free. We optimised the primary parameters using pyrethroid-susceptible and -resistant mosquito strains exposed to new pyrethroid-chlorfenapyr ITNs versus controls. With parameters defined, we used a draft standard operating procedure (SOP) to evaluate the mini chamber against the gold standard tunnel test in a comparator study. The generated data were used to finalise an SOP. The number of mosquitoes per bioassay had no effect on 72 hour mortality on exposure to the pyrethroid-chlorfenapyr net (10, 20, or 30 mosquitoes per mini chamber: 98% vs. 99% vs. 99%, p = 0.46), nor did the chamber orientation (horizontal vs. vertical: 70% vs. 74%, p = 0.35). Mean 72-hour mortality reduced with the length of exposure: 99% with overnight exposure, 74% with 4 hours and 35% with 2 hour exposure. In direct comparisons, the mini chamber gave 95% 72 hour mortality and the tunnel test 70% with overnight exposure. A trend was observed between chemical content (measured by high performance liquid chromatography (HPLC)) and mortality in ITN samples that had been washed 20 times or used in experimental hut trials, compared to unused comparators, when a 6 hour exposure length was used, showing potential for application to durability monitoring. A mini chamber SOP is shared ( https://github.com/i2i-Data-Repository/Mini-Chamber-Test-paper-data-R-code-and-SOP), and further improvements may come from internal and multi-site validation and review of data generated. The method shows promise as an effective bioassay for use where tunnel tests are not available, for measuring the biological activity of chlorfenapyr in ITNs when measuring regeneration times, wash resistance, residual efficacy, and other studies.

Indexed as

Biological AssayInsecticidesInsecticide-Treated BednetsMalariaMosquito ControlPyrethrinsAnimalsAnophelesFemaleHumansInsecticide ResistancechlorfenapyrInsecticidesPyrethrinsAnophelesBioassaysbioefficacychlorfenapyrinsecticide treated netsmosquitovector control

Identifiers

PMID41972098
PMCPMC13062344

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.