6.4 Low-carbon housing measures and vector-borne disease control 6.4.1 Home improvements to reduce Chagas disease Housing improvements have long been used as a preventive strategy against Chagas disease in southern Latin America. The disease is spread by triatomine bugs that traditionally lived primarily in forests, but over the past century have become a much more serious problem in rural and urban dwellings as a result of urbanization, deforestation and increased rural/peri-urban development. Housing improvements shown to reduce triatomine vector infestation include concrete floors, plaster, brick walls and tiled roofs.5 A more recent study in Jutiapa, Guatemala, evaluated seventeen variables as possible risk factors for infestation with Triatoma dimidiata. During 2004, 644 houses were assessed for vector presence and evaluated for hygiene, cluttering, material comfort, construction conditions and number of inhabitants, among other factors. The study showed a greater chance of vector presence when walls lacked plaster (3.85 times) or had low-quality incomplete plastering (4.56 times) compared with walls that were completely plastered, as well in houses with poor sanitation and other construction conditions.6
6.4.2 Dengue control through water storage container management The most productive larval habitats for Aedes mosquito reproduction typically are water storage containers in and around houses where piped water is unavailable, and debris (e.g. old tires) which accumulate rainwater and thus provide breeding grounds. Systematic reviews and field studies have identified methods to identify the most “productive” larval habitats and then target these habitats with vector control interventions. These control measures can include many environmentally friendly interventions such as water storage, sanitation and waste cleanup measures that can in turn reduce reliance on chemical spraying. Covering water containers and larviciding water containers, including with biological predators or agents, have been found to be particularly effective, dependent on the local eco-epidemiological setting.7–12 The WHO/UNDP/UNICEF/ World Bank Special Programme for Research and Training in Tropical Diseases (WHO/ TDR) is carrying out a series of field studies on improved eco-bio-social management of dengue and Chagas in nine Latin American and six South-East Asian communities in order to fine-tune intervention strategies based on good environmental management.
6.4.3 Lime-plastering of walls in visceral leishmaniasis control Typically, sand fly vector control in India is carried out with indoor residual spraying (IRS), often with DDT, a use of persistent organic pollutants (POPs) that is permitted under the Stockholm Convention on vector borne-disease control. One recent intervention study carried out under the auspices of WHO/TDR found that traditional lime-plastering of walls, while not quite as effective as DDT, still had excellent efficacy in reducing sand fly vector densities over a five-month period in two Indian and Nepalese study sites.13 Further exploration of low-carbon housing improvements that promote visceral leishmaniasis vector control, in conjunction with long-lasting 108 Health co-benefits of climate change mitigation – Housing sector