Abstract
Background: Anopheles gambiae, the major malaria mosquito in sub-Saharan Africa, feed largely indoors at night. Raising a house off the ground with no barriers underneath reduces mosquito-house entry. This experiment tested whether walling off the space under an elevated hut affects mosquito-hut entry. Methods: Four inhabited experimental huts, each of which could be moved up and down, were used in rural Gambia. Nightly collections of mosquitoes were made using light traps and temperature and carbon dioxide levels monitored indoors and outdoors using loggers. Each night, a reference hut was kept at ground level and three huts raised 2 m above the ground; with the space under the hut left open, walled with air-permeable walls or solid walls. Treatments were rotated every four nights using a randomized block design. The experiment was conducted for 32 nights. Primary measurements were mosquito numbers and indoor temperature in each hut. Results: A total of 1,259 female Anopheles gambiae sensu lato were collected in the hut at ground level, 655 in the hut with an open ground floor, 981 in the hut with air-permeable walls underneath and 873 in the hut with solid walls underneath. Multivariate analysis, adjusting for confounders, showed that a raised hut open underneath had 53% fewer mosquitoes (95% CI 47–58%), those with air-permeable walls underneath 24% fewer (95% CI 9–36%) and huts with solid walls underneath 31% fewer (95% CI 24–37%) compared with a hut on the ground. Similar results were found for Mansonia spp. and total number of female mosquitoes, but not for Culex mosquitoes where hut entry was unaffected by height or barriers. Indoor temperature and carbon dioxide levels were similar in all huts. Conclusion: Raising a house 2 m from the ground reduces the entry of An. gambiae and Mansonia mosquitoes, but not Culex species. The protective effect of height is reduced if the space underneath the hut is walled off.
| Original language | English |
|---|---|
| Article number | 100 |
| Journal | Malaria Journal |
| Volume | 23 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2024 |
Bibliographical note
Publisher Copyright:© 2024. The Author(s).
Funding
This work was supported by pump-prime funding from the BOVA Network (Building Out Vector-borne diseases in sub-Saharan Africa). SWL and MCT are supported by the Global Challenges Research Fund for networks in vector borne disease research which is co-funded by BBSRC, MRC and NERC (BB/R00532X/1) and MCT was supported by the Durham Global Challenges Centre for Doctoral Training. The funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. All authors had full access to all data in the studies and had final responsibility for the decision to submit for publication.
| Funders | Funder number |
|---|---|
| BOVA Network | |
| Medical Research Council | |
| Biotechnology and Biological Sciences Research Council | |
| Building Out Vector-borne diseases in sub-Saharan Africa | |
| Natural Environment Research Council | BB/R00532X/1 |
Keywords
- Anopheles gambiae
- Housing
- Malaria
- Mosquitoes
- Sub-Saharan Africa
