Bio-efficacy of field aged novel class of long-lasting insecticidal nets, against pyrethroid-resistant malaria vectors in Tanzania: A series of experimental hut trials
Bibliographic record
Abstract
Abstract New classes of long-lasting insecticidal nets (LLINs) incorporating two insecticides, or an insecticide and a synergist, are recommended by the World Health Organization (WHO) to prevent malaria transmitted by mosquito vectors resistant to pyrethroid and other common insecticide classes. This study was nested in a large-scale cluster-randomized controlled trial conducted in Tanzania. A series of experimental hut trials (EHTs) aimed to evaluate the bio-efficacy of trial LLINs on the mosquito indicators most pertinent to malaria transmission over 3 years of use in the community. The aim was to evaluate nets subjected to a broader range of household factors than WHO standardized washing. The following field collected LLINs were assessed: 1/Olyset TM Plus (combining piperonyl butoxide synergist and permethrin), 2/Interceptor ® G2 (chlorfenapyr and alpha-cypermethrin), 3/Royal Guard ® (pyriproxyfen and alpha-cypermethrin), 4/Interceptor ® (alpha-cypermethrin only), 5/a new Interceptor ® , and 6/an untreated net. Thirty nets of each type were withdrawn from the community at 12, 24 and 36 months after distribution and used for the EHTs. Pre-specified outcomes were 72-hour mortality for Interceptor ® G2, 24-hour mortality for Olyset TM Plus, and fertility based on egg development stage for Royal Guard ® . Overall; Interceptor ® G2 LLINs induced higher 72-hour mortality compared to standard LLINs of the same age up to 12 months (44% vs 21%), OR: 3.5, 95% CI: 1.9 – 6.6, p-value < 0.001 and 24-hour mortality was only significantly higher in Olyset TM Plus when new (OR: 13.6, 95%CI: 4.4 – 41.3, p-value < 0.001) compared to standard LLINs but not at 12 months (17% vs 13%; OR: 2.1, 95% CI: 1.0 – 4.3; p-value = 0.112). A small non-significant effect of pyriproxyfen on Anopheles fertility was observed for Royal Guard ® up to 12 months (75% vs 98%, OR: 1.1, 95% CI: 0.0 – 24.9, p-value = 0.951). There was no evidence of a difference in the main outcomes for any of the new class of LLINs at 24 and 36 months compared to standard LLINs. Interceptor ® G2 LLINs showed superior bio-efficacy compared to standard LLINs for only up to 12 months and the effect of Olyset TM Plus was observed when new for all species and 12 months for An. gambiae s.l. only. The pyriproxyfen component of Royal Guard ® had a short and limited effect on fertility
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.011 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".