Durability of the deltamethrin-treated polypropylene long-lasting net LifeNet® in a pyrethroid resistance area in south western Benin: A phase III trial

• Published in: PloS one Vol. 18; no. 9; p. e0291755
• Main Authors: Djènontin, Armel, Alfa, Daleb, Bouraima, Aziz, Soares, Christophe, Dahounto, Amal, Cornélie, Sylvie, Egrot, Marc, Damien, Georgia, Remoué, Franck, Sagna, André Barembaye, Moiroux, Nicolas, Pennetier, Cédric
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 20.09.2023; Public Library of Science (PLoS)
• Subjects: Bioassays; Biology and Life Sciences; Censuses; Clinical trials; Collaboration; Communication; Community; Criteria; Deltamethrin; Durability; Effectiveness; Global positioning systems; GPS; Households; Human health and pathology; Infectious diseases; Insecticide resistance; Insecticides; Life Sciences; Longitudinal studies; Malaria; Medicine and Health Sciences; Mortality; Performance assessment; Pesticides; Physical Sciences; Polyethylene; Polypropylene; Pyrethroids; Questionnaires; Rural areas; Santé publique et épidémiologie; Seasons; Side effects; Sociodemographics; Survival; Tunnels; Vector-borne diseases; Benin
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0291755

Background Long-lasting insecticidal bed nets (LLINs) are a key measure for preventing malaria and their evaluation is coordinated by the World Health Organization Pesticide Evaluation Scheme (WHOPES). LifeNet ® was granted WHOPES time-limited interim recommendation in 2011 after successful Phase I and Phase II evaluations. Here, we evaluated the durability and community acceptance of LifeNet ® in a Phase III trial from June 2014 to June 2017 in Benin rural area. Methods A prospective longitudinal, cluster-randomized, controlled trial with households as the unit of observation was designed to assess the performance of LifeNet® over a three-year period, using a WHOPES fully recommended LLIN (PermaNet ® 2.0) as a positive control. The primary outcomes were the bioassay performance using WHO cone assays and tunnel tests, the insecticide content and physical integrity. Results At baseline, 100% of LLINs were within the tolerance limits of their target deltamethrin concentrations. By 36 months only 17.3% of LifeNet ® and 8.5% of PermaNet ® LLINs still were within their target deltamethrin concentrations. Despite these low rates, 100% of both LLINs meet WHO efficacy criteria (≥ 80% mortality or ≥ 95% knockdown or tunnel test criteria of ≥ 80% mortality or ≥ 90% blood-feeding inhibition) after 36 months using WHO cone bio-assays and tunnel tests. The proportion of LLINs in good physical condition was 33% for LifeNet ® and 29% for PermaNet ® after 36 months. After 36 M the survivorship was 21% and 26% for LifeNet® and PermaNet® respectively. Although both LLINs were well accepted by the population, complaints of side effects were significantly higher among LifeNet ® users than PermaNet ® ones. Conclusion LifeNet ® LLINs did meet WHO criteria for bio-efficacy throughout the study period and were well accepted by the population. This is an important step towards getting a full WHO recommendation for use in malaria endemic countries.