The efficacy of insecticide-treated window screens and eaves against Anopheles mosquitoes: a scoping review

Abstract

Background Female mosquitoes serve as vectors for a host of illnesses, including malaria, spread by the Plasmodium parasite. Despite monumental strides to reduce this disease burden through tools such as bed nets, the rate of these gains is slowing. Ongoing disruptions related to the COVID-19 pandemic may also negatively impact gains. The following scoping review was conducted to examine novel means of reversing this trend by exploring the efficacy of insecticide-treated window screens or eaves to reduce Anopheles mosquito bites, mosquito house entry, and density. Methods Two reviewers independently searched PubMed, Scopus, and ProQuest databases on 10 July, 2020 for peer-reviewed studies using insecticide-treated screens or eaves in malaria-endemic countries. These articles were published in English between the years 2000–2020. Upon collection, the reports were stratified into categories of biting incidence and protective efficacy, mosquito entry and density, and mosquito mortality. Results Thirteen out of 2180 articles were included in the final review. Eaves treated with beta-cyfluthrin, transfluthrin or bendiocarb insecticides were found to produce vast drops in blood-feeding, biting or mosquito prevalence. Transfluthrin-treated eaves were reported to have greater efficacy at reducing mosquito biting: Rates dropped by 100% both indoors and outdoors under eave ribbon treatments of 0.2% transfluthrin (95% CI 0.00–0.00; p < 0.001). Additionally, co-treating window screens and eaves with polyacrylate-binding agents and with pirimiphos-methyl has been shown to retain insecticidal potency after several washes, with a mosquito mortality rate of 94% after 20 washes (95% CI 0.74–0.98; p < 0.001). Conclusions The results from this scoping review suggest that there is value in implementing treated eave tubes or window screens. More data are needed to study the longevity of screens and household attitudes toward these interventions.

Participatory development of practical, affordable, insecticide-treated mosquito proofing for a range of housing designs in rural southern Tanzania

“…Consistent with dozens of previous reports, this study confirms that screening of houses reduces indoor mosquito densities, even without any insecticide [ 8 , 9 , 54 ]. Furthermore, the observations confirm that house screening has a far greater impact upon indoor densities of Anopheles , in this case An.…”

“…Further studies that extend such approaches across much larger populations, and which include formal costing and social science investigations, are clearly merited to more rigorously assess their scalability. Consistent with dozens of previous reports, this study confirms that screening of houses reduces indoor mosquito densities, even without any insecticide [8,9,54]. Furthermore, the observations confirm that house screening has a far greater impact upon indoor densities of Anopheles, in this case An.…”

Semi-field evaluation of a volatile transfluthrin-based intervention reveals efficacy as a spatial repellent and evidence of other modes of action

“…Prior studies of transfluthrin have utilized proxy measurements for blood feeding such as HLC [ 45 ], or allowed mosquitoes to freely bite to measure reductions in blood feeding [ 28 ]. It has been suggested in Aedes mosquitoes that landing and biting inhibition might differ [ 46 ], and separating these endpoints allows for host-seeking and probing behaviors to be considered separately.…”

Semi-field evaluation of electrocuting eave tubes for the control of endophagic mosquitoes in south-east Tanzania

“…Examples are screens treated with biological control agent (e.g. entomopathogenic fungi) [45], insecticidal eave curtains [46,47],…”