Project Lead(s): Thomas Egwang
Traditionally, malaria control has consisted of chemotherapy using drugs such as chloroquine, sulfadoxine-pyrimethamine (SP, Fansidar) and artemisinin-based combination therapies (ACT); and vector control by indoor residual spraying (IRS) and long-lasting, insecticide-treated bed nets (LLITNs).
These control efforts are hindered by antimalarial drug resistance by malaria parasites, which has rendered practically obsolete chloroquine and SP, and currently threatens the future of ACT in Africa.
IRS is expensive, requires trained staff, does not reach remote areas (due to bad roads) and is often rejected by communities. LLITNs have poor coverage and are often incorrectly or never used by those who own them.
The project investigated the feasibility of a village-driven, village-based malaria eradication program, based on plastering mud walls of village huts with soil mixed with insecticides.
Villagers themselves mix World Health Organization-approved insecticides with local plaster materials (such as coloured soils, which are freely available in the fields and gardens) and apply the insecticide-treated plaster onto mud walls of village huts.
The insecticides are subsidized by the government.
The most significant project-related achievement included a demonstration that locally and freely available soil, when mixed with insecticides and used as plaster on hut mud walls, has insecticidal activity similar to the Indoor Residual Spraying gold standard.
Wall surfaces plastered with insecticide-treated soil had a definite adverse effect on mosquitoes: 65 % of mosquitoes were knocked down after 60 minutes’ exposure versus 100% of mosquitoes exposed to IRS-treated walls.
All mosquitoes exposed to wall surfaces covered with insecticide-treated soil were dead after 24 hours, similar to the 100% mortality rate observed with IRS-treated walls.
The cost of the low-tech approach of plastering a hut is significantly less than the cost of IRS in spraying the same hut, because IRS involves the cost of insecticide, spray pumps, repair kits, sprayers, drivers, team leaders and training.
By contrast, the low-tech factors in only the cost of insecticides and a small amount for transport from government stores and distribution to villagers.
The most important changes that resulted from the project were that community members and their leaders were sensitized to the role of mosquitoes in malaria transmission, and how to reduce mosquito/human contacts.
This resulted in behaviour practices that contributed to malaria mosquito vector control, as measured by the number of homes in which puddles and tire ruts were filled with murram to eliminate mosquito breeding sites.
The plan is to scale the project by executing key field studies to confirm the efficacy of the low-tech approach against malaria transmission.
Sustainability will also be ensured by combining the low-tech approach with another community-based control effort (e.g., mass ivermectin treatment) for malaria eradication.