The effect of light and ventilation on house entry by Anopheles arabiensis sampled using light traps in Tanzania: an experimental hut study
Issued Date
2022-12-01
Resource Type
eISSN
14752875
Scopus ID
2-s2.0-85124208296
Pubmed ID
35123497
Journal Title
Malaria Journal
Volume
21
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Malaria Journal Vol.21 No.1 (2022)
Suggested Citation
Mmbando A.S., Bradley J., Kazimbaya D., Kasubiri R., Knudsen J., Siria D., von Seidlein L., Okumu F.O., Lindsay S.W. The effect of light and ventilation on house entry by Anopheles arabiensis sampled using light traps in Tanzania: an experimental hut study. Malaria Journal Vol.21 No.1 (2022). doi:10.1186/s12936-022-04063-3 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/84868
Title
The effect of light and ventilation on house entry by Anopheles arabiensis sampled using light traps in Tanzania: an experimental hut study
Author's Affiliation
Faculty of Tropical Medicine, Mahidol University
Nelson Mandela African Institution of Science and Technology
Ifakara Health Institute
Durham University
Royal Danish Academy – Architecture, Design, Conservation
Medical Research Council
Wits School of Public Health
College of Medical, Veterinary & Life Sciences
Nelson Mandela African Institution of Science and Technology
Ifakara Health Institute
Durham University
Royal Danish Academy – Architecture, Design, Conservation
Medical Research Council
Wits School of Public Health
College of Medical, Veterinary & Life Sciences
Other Contributor(s)
Abstract
Background: In sub-Saharan Africa, house design and ventilation affects the number of malaria mosquito vectors entering houses. This study hypothesized that indoor light from a CDC-light trap, visible from outside a hut, would increase entry of Anopheles arabiensis, an important malaria vector, and examined whether ventilation modifies this effect. Methods: Four inhabited experimental huts, each situated within a large chamber, were used to assess how light and ventilation affect the number of hut-entering mosquitoes in Tanzania. Each night, 300 female laboratory-reared An. arabiensis were released inside each chamber for 72 nights. Nightly mosquito collections were made using light traps placed indoors. Temperature and carbon dioxide concentrations were measured using data loggers. Treatments and sleepers were rotated between huts using a randomized block design. Results: When indoor light was visible outside the huts, there was an 84% increase in the odds of collecting mosquitoes indoors (Odds ratio, OR = 1.84, 95% confidence intervals, 95% CI 1.74–1.95, p < 0.001) compared with when it was not. Although the odds of collecting mosquitoes in huts with closed eaves (OR = 0.54, 95% CI 0.41–0.72, p < 0.001) was less than those with open eaves, few mosquitoes entered either type of well-ventilated hut. The odds of collecting mosquitoes was 99% less in well-ventilated huts, compared with poorly-ventilated traditional huts (OR = 0.01, 95% CI 0.01–0.03, p < 0.001). In well-ventilated huts, indoor temperatures were 1.3 °C (95% CI 0.9–1.7, p < 0.001) cooler, with lower carbon dioxide (CO2) levels (mean difference = 97 ppm, 77.8–116.2, p < 0.001) than in poorly-ventilated huts. Conclusion: Although light visible from outside a hut increased mosquito house entry, good natural ventilation reduces indoor carbon dioxide concentrations, a major mosquito attractant, thereby reducing mosquito-hut entry.