Despite evidence that housing plays an important role in the eradication of malaria, it is often overlooked.
As World Malaria Day gets closer each year, organizations release an increasing number of reports on the progress achieved and what needs to be done to eliminate the disease. Despite vast evidence that housing can play an important role in the eradication of malaria in many regions in the world, many of these reports fail to mention the importance of housing in malaria reduction. Today’s reality of growing slums and deteriorating health conditions calls for a joint approach of two often-considered separate sectors – housing and health. Many of the biggest urban centers in the world are now located in sub-Saharan Africa, where 72 percent of its urban population live in slum conditions. As 90 percent of malaria cases occur in sub-Saharan Africa, we must look into the links between housing and malaria if we are to eradicate this disease.
For the past decades, key health and funding organizations aimed at eliminating malaria have been targeting the reduction of Anopheles mosquitoes, the main malaria vector, through indoor residual insecticide spraying (IRS), and insecticide-treated bed nets (ITNs). The World Bank, one of the three largest sources of funds in the fight against malaria, has recently committed $200 million to provide people in sub-Saharan Africa with 25 million insecticide treated bednets. UNITAID has also provided 109 million to UNICEF to buy and distribute 20 million bednets in eight high-burden countries in 2009-2010. The World Health Organization estimates that nearly all sub-Saharan African countries had adopted the policy of providing bednets to children and pregnant women by the end of 2006.
Despite the results achieved through these strategies, mosquitoes are becoming increasingly resistant to insecticides, including pyrethroids, which are present in bed nets and sprays, particularly in Africa. While insecticides can be effective in controlling malaria, such as DDT, they also represent a major threat to human health and the environment. Regarding bed nets and antimalarials, it has been observed that in all sub-Saharan African countries there is a strong relationship between household wealth and the use of bednets and anti-malarials by children. Children in rich households are 60 percent more likely to sleep underbed nets and receive medication when they have a fever when compared to children in poor households.
This means that malaria affects human populations unevenly. Malaria treatment and preventive measures can cost poor households 25% of their total available income (AMREF, 2006). Although many corporations continue to invest heavily in this strategy, failure to address the disparities in bed-net usage and treatment may likely mean a loss in the effectiveness of donor funds. Perhaps it might be time to broaden the scope of strategies deployed – to include improvement in living/housing conditions.
Studies done in several sub-Saharan African countries have proved that simple, low-cost improvements in traditional houses, which prevent mosquitoes from entering the home and reaching humans, contribute to reducing the number of malaria cases. Screening windows, closing eaves and upgrading the materials of ceilings are some of the efficient strategies that can contribute to decrease the number of people affected by malaria – through limiting vector entry.
Housing as a strategy against malaria includes not only the physical houses per se but also the immediate surroundings around the home, which can represent excellent sites for mosquito breeding. Studies show that malaria transmission is strongly associated with the location of mosquito breeding. The Anopheles mosquito likes to breed in fresh water or brackish water close to human settlements as they rarely fly more than 1km to find a blood meal. The lack of adequate waste management systems and awareness in many urban and peri-urban areas contributes to the expansion of malaria vector breeding sites near human settlements. Buckets, old tires, open tanks and ponds are some of the attractive sources for mosquitoes to breed and pose a major health risk to residents. Simple measures such as clearing ponds, closing water containers and eliminating other potential breeding sites can substantially decrease the population of malaria vectors and reduce the risk of malaria transmission.
Poor households are again the most vulnerable to malaria since they live in houses that are frequently built with materials that deplete quickly and are located in areas with no waste management system in place. According to a study carried out in Sri Lanka, the risk of getting malaria was greater for residents of the poorest type of house construction (incomplete, mud, or palm walls, and thatched roofs) compared to houses with complete brick and plaster walls and tiled roofs.
The combination of larval control methods with simple housing improvements can drastically reduce people’s exposure to mosquitoes infected with the malaria parasite and consequently to disease. As mosquitoes are becoming resistant to insecticides and anti-malarial drugs, we urgently need new methods for controlling mosquitoes and treatments for infection. It’s time for us to consider housing and the elimination of vector-breeding sites near the home as a viable and effective strategy to help end malaria.
Alexandra Valerio is a project coordinator at Architecture for Health In Vulnerable Environments.