Impact and cost-effectiveness of a lethal house lure against malaria transmission in central Côte d'Ivoire: a two-arm, cluster-randomised controlled trial

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.

Section: Discussionsupporting

confidence: 92%

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

Anaele

Varshney

Ugwu

et al. 2021

“…from cluster randomised controlled trials. Other options may be to consider this in the same class as lethal house lures [ 69 ] or spatial repellents [ 70 ], for which epidemiological evidence is either partially available or is underway. Unlike eave tubes, the ribbons can be fitted onto any house type and do not require any additional construction to fill up the eave spaces.…”

Section: Introductionmentioning

confidence: 99%

Insecticide-treated eave ribbons for malaria vector control in low-income communities

Kaindoa

Mmbando

Shirima

et al. 2021

Supplementary tools are required to address the limitations of insecticide-treated nets (ITNs) and indoor residual spraying (IRS), which are currently the core vector control methods against malaria in Africa. The eave ribbons technology exploits the natural house-entry behaviours of major malaria vectors to deliver mosquitocidal or repellent actives around eave spaces through which the Anopheles mosquitoes usually enter human dwellings. They confer protection by preventing biting indoors and in the peri-domestic outdoor spaces, and also killing a significant proportion of the mosquitoes. Current versions of eave ribbons are made of low-cost hessian fabric infused with candidate insecticides and can be easily fitted onto multiple house types without any additional modifications. This article reviews the evidence for efficacy of the technology, and discusses its potential as affordable and versatile supplementary approach for targeted and efficient control of mosquito-borne diseases, particularly malaria. Given their simplicity and demonstrated potential in previous studies, future research should investigate ways to optimize scalability and effectiveness of the ribbons. It is also important to assess whether the ribbons may constitute a less-cumbersome, but more affordable substitute for other interventions, such as IRS, by judiciously using lower quantities of selected insecticides targeted around eave spaces to deliver equivalent or greater suppression of malaria transmission.

“…Housing improvements tend to be implemented as a package and, in line with this, our study found that metal-roof sleeping spaces were more likely to have floors and walls made of finished materials than thatch-roof sleeping spaces. Improving house construction should be a focus for malaria reduction, with increasing evidence in support of screened, self-closing doors, closed eaves, raising buildings off the ground, screened windows on either side of building for ventilation and solid roofs [ 16 , 38 , 39 ]. As well as contributing to the development agenda, there is also evidence that improved housing can reduce risk of other major causes of death in children including diarrhoea, growth failure and anaemia [ 40 ].…”

Section: Discussionmentioning

confidence: 99%

Risk factors associated with house entry of malaria vectors in an area of Burkina Faso with high, persistent malaria transmission and high insecticide resistance

Yaro

Tiono

Sanou

et al. 2021

Self Cite

Background In rural Burkina Faso, the primary malaria vector Anopheles gambiae sensu lato (s.l.) primarily feeds indoors at night. Identification of factors which influence mosquito house entry could lead to development of novel malaria vector control interventions. A study was therefore carried out to identify risk factors associated with house entry of An. gambiae s.l. in south-west Burkina Faso, an area of high insecticide resistance. Methods Mosquitoes were sampled monthly during the malaria transmission season using CDC light traps in 252 houses from 10 villages, each house sleeping at least one child aged five to 15 years old. Potential risk factors for house entry of An. gambiae s.l. were measured, including socio-economic status, caregiver’s education and occupation, number of people sleeping in the same part of the house as the child, use of anti-mosquito measures, house construction and fittings, proximity of anopheline aquatic habitats and presence of animals near the house. Mosquito counts were compared using a generalized linear mixed-effect model with negative binomial and log link function, adjusting for repeated collections. Results 20,929 mosquitoes were caught, of which 16,270 (77.7%) were An. gambiae s.l. Of the 6691 An. gambiae s.l. identified to species, 4101 (61.3%) were An. gambiae sensu stricto and 2590 (38.7%) Anopheles coluzzii. Having a metal-roof on the child’s sleeping space (IRR = 0.55, 95% CI 0.32–0.95, p = 0.03) was associated with fewer malaria vectors inside the home. Conclusion This study demonstrated that the rate of An. gambiae s.l. was 45% lower in sleeping spaces with a metal roof, compared to those with thatch roofs. Improvements in house construction, including installation of metal roofs, should be considered in endemic areas of Africa to reduce the burden of malaria.