Can improved housing provide additional protection against clinical malaria over current best practice? A household-randomised controlled trial

Malaria remains one of the greatest threats to global public health, with 207 million cases of falciparum malaria and 627,000 deaths occurring in 2012, with over 80% of deaths occurring in Africa. More than 80% of malaria is transmitted indoors at night, so the number of malaria mosquitoes which enter a house is critical for getting the disease - with people living in 'leaky' houses being at most risk. We have shown that closing the eaves (the gap between the top of the wall and the roof) and screening a house can reduce dramatically the number of malaria vectors entering a house. Here we propose to find out whether we can protect children against malaria by modifying half the study houses so that they (1) have a metal roof, (2) closed eaves, (3) screened doors and windows and (4) screened-air bricks which allow the warm air to rise out of the house, but not let any mosquitoes indoors. The other study houses will be left with thatched roofs and open eaves and the children in these houses will serve as a comparison group. Over the past thirty years a silent revolution in house design has been happening across Africa. The traditional thatched-roofed houses are being replaced steadily by metal-roofed houses as the continent develops. We hope to ride this wave of cultural change and further improve the design of houses to make them healthier to live in. Improved housing has the potential to improve the lives of millions of people across sub-Saharan Africa.

Malaria remains one of the greatest threats to global public health, with 207 million cases of falciparum malaria and 627,000 deaths occurring in 2012, with over 80% of deaths occurring in Africa. More than 80% of malaria is transmitted indoors at night, so the number of infective mosquitoes which enter a house is critical for getting the disease - with people living in 'leaky' houses being at most risk. We have shown that closing the eaves (the gap between the top of the wall and the roof) and screening a house can reduce dramatically the number of malaria vectors entering a house. Here we propose to determine whether we can reduce the incidence of clinical malaria in children living in well-screened houses, which have a (1) a metal roof, (2) closed eaves, (3) screened doors and windows and (4) screened-air bricks which allow the warm air to rise out of the house, but not let any mosquitoes indoors. The control houses will be left with thatched roofs and open eaves. We will also carry out subsidiary studies to find out whether the interventions are cost effective and develop a strategy for scaling-up housing interventions. Across Africa a silent revolution in house design has been happening for several decades. The traditional thatched-roofed houses are being replaced by metal-roofed houses as the continent develops. We hope to ride this wave of cultural change and further improve the design of houses to make them healthier to live in. Improved housing has the potential to improve the lives of millions of people across sub-Saharan Africa.

To our knowledge this is the first randomised controlled trial against clinical malaria where housing has been used as an intervention against malaria. This research is designed to improve housing and reduce malaria in rural (and urban) communities in The Gambia and other countries in sub-Saharan Africa. Over 144 million rural houses will be built in Africa by 2050, assuming an average family of about 5 people per house, and uninterrupted growth rates. This represents an extraordinary opportunity to help guide building design in rural areas; to modernise and create healthy homes, especially since consumer spending will almost double in Africa in the next decade, creating a markedly improved housing stock, with people investing in their own homes. The results of the proposed trial will help inform the Gambian Medical and Health Department and other African Departments of Health of the potential benefits of improved housing to control malaria. Perhaps more importantly it provides African Governments and the development community with a way of not only improving people's quality of life directly, but also indirectly by providing a healthy home. Thus the research will be of interest to NGOs like DfID and DANIDA, organisations with a special interest in housing such as Archive, Habitat for Humanity, Architects without Borders and UN Habitat, as well as providing the World Health Organisation, Roll Back Malaria and the United Nations Development Programme with valuable information on the benefits of a healthy home.There are also likely to be commercial benefits to this research. The construction of large numbers of houses will help boost the local construction industry in The Gambia, and elsewhere, providing income for builders and suppliers of building materials (air bricks, screening and metal roofing) locally and internationally. There are many commercial companies that produce mosquito screening (e.g. Vestergaard Frandsen, Bug Off Screens).