Scientists are using weather forecasts to predict the location and scale of impending meningitis outbreaks in sub-Saharan Africa, in order to give health agencies more time to activate emergency response plans.
This approach is being piloted by a collaboration involving researchers and meteorological agencies in Africa and the UK. Partners include the African Centre of Meteorological Applications for Development, the University of Leeds, the National Centre for Atmospheric Science, the UK Centre for Ecology & Hydrology (UKCEH), the University of Reading and the Met Office.
The scientists are using weather forecast data to produce ‘meningitis vigilance’ maps and provide a warning of conditions that are likely to trigger an outbreak up to two weeks’ in advance.
A large area of Africa from Senegal in the west to Ethiopia on the east coast has been described as the continent’s ‘meningitis belt’, with an increased risk of outbreaks during the dry season from November to June. Cases rise dramatically in hot, dry and dusty weather because dust particles irritate people’s airways and allow airborne microorganisms to get into the body and cause meningitis, an infection of the membrane surrounding the brain and spinal column.
Once an outbreak starts, it spreads rapidly from person to person. There are about 30,000 cases in Africa each year, with one in 10 infected people dying and others left with brain damage, epilepsy or deafness.
Dr Joshua Talib, a climate scientist at UKCEH, explains: “While our forecasts cannot stop infections, predicting where and when there could be future outbreaks enables medical services to be made available in these areas to people most likely to be affected by meningitis. This will reduce the severity of symptoms and fatalities.
"At present, predictions are provided at a regional scale of approximately 200km but scientists are working hard to improve the resolution and accuracy of forecasts.”
An intense dust storm in Mali Picture: Françoise Guichard/Laurent Kergoat/CNRS Photo Library
The pilot project is evaluating how well the forecasts predict weather conditions, the link between weather conditions and meningitis cases, and the methods of communication between climate scientists and health organisations. By analysing factors such as humidity, air quality, temperature and wind speed, researchers can map those areas where conditions will be ideal for an outbreak to occur.
The research is part of African SWIFT, an initiative - funded by the UK Government’s Global Challenges Research Fund – which is improving weather forecasting on a continent where sudden and extreme weather events can result in loss of life and livelihoods.
Professor Doug Parker of the University of Leeds, lead scientist of African SWIFT, explains: “Researchers have known about the link between weather conditions and meningitis for decades. But with advances in weather modelling, we can now forecast with a high degree of accuracy one or two weeks ahead whether those conditions will develop.
“We are in the middle of the African meningitis ‘season’ and so can assess how effective the specialised weather forecasts are in helping to better coordinate health action on the ground.”
The World Health Organisation has published guidelines to help health agencies in Africa deal with an outbreak of meningitis. These include having robust surveillance systems to detect early signs of an outbreak and, when it occurs, taking samples from patients to determine the type and strain of pathogen involved and making sure laboratories are ready to deal with an increase in testing.
People who are ill should be given appropriate antibiotics as soon as possible and, if the outbreak turns into an epidemic, health organisations need to consider mass immunisation if there is a vaccine that works against that particular pathogen.
Dr Ado Mpia Bwaka of the WHO’s Regional Office for Africa, says: “Being able to predict the likelihood that atmospheric conditions will cause a meningitis outbreak is a powerful tool that helps countries to strengthen meningitis surveillance. It will also help to make decisions about how best to target resources when an outbreak occurs.”