Mosquito-Proofing Buildings
Based on their work in developing pilot housing, Gauge was asked to submit proposals for pilot housing which investigated methods discouraging mosquito entry into buildings as a way of reducing malaria transmission. A literature review was carried out and came up with the following interesting findings.
Air movement
Mosquitoes are characterized as poor fliers and are negatively affected by flowing air (Service, 1980) Service (1980) finds that mosquitoes drastically reduce host seeking flights when wind speeds exceed 3km/hr. Résearch by Rogozi et al (2012) on the capturability of adult mosquitoes find that there is an inverse relationship between windspeeds and the number of mosquitoes caught. Hoffmann and Miller (2003) investigate the utility of wind in the suppression of mosquitoes and conclude that ‘fan-generated’ wind can be an effective way of protecting humans from mosquitoes.
Height
Sleeping on a raised structure was a technique used in ancient Egypt to avoid mosquitoes (de Selincourt, 2002). In research in Vietnam, Laderman (1975) found that hill people built their houses on stilts to avoid mosquitoes which seldom flew higher than 2 to 3 meters above ground level. Charlwood et al (2003) found that buildings built on legs off the ground had half the number of mosquitoes in them compared to buildings on ground level. Their research indicated that there could be an 18-fold difference in exposure to malaria vectors between houses built on the ground and on stilts 10m apart.
Plants
Sambali et al (2011) carried out research on the use of live plants as a means of reducing mosquito entry into housing in Tanzania. Their study showed that planting densely foliated Lantana Camara around houses reduced the presence of mosquitoes by 50% compared to houses without planting. They find that there is broad community acceptance of Lantana and that planting sufficient plants to achieve mosquito repellent for one home cost about 30c per person.
Seyoum, et al 2003 investigated the extent to which Ocimum americanum, Lantana camara and Lippia ukambensis repelled mosquitoes in buildings. Plants in pots were placed under eaves in buildings in Kenya and findings indicated that Ocimum americanum reduced mosquitoes in buildings by 37% and that Lantana camara reduced mosquitoes by 27% compared to buildings where there were no plants. Seyoum concludes that the use potted plants are a highly cost-effective means of achieving household protection against mosquitoes in buildings.
Projects based on this investigation have been proposed and involve the construction of simple housing types that can be used to assess the efficacy of different methods of repelling mosquitoes.