Global experts unite to fight the scourge of meningitis in Africa
The London School of Hygiene & Tropical Medicine (LSTHM) is to lead a global consortium aimed at better understanding how meningococcal meningitis is transmitted, and to document the impact of a new meningitis vaccine on reducing transmission of the disease.
The initiative has been made possible by grants of almost $7 million (£5 million) from the Bill & Melinda Gates Foundation and $3.7m (£2.25 million) from the Wellcome Trust.
The African Meningococcal Carriage Consortium (MenAfriCar) will be the largest, most concerted effort to date to understand how meningococcal meningitis is spread in Africa. This disease which, in 2008 alone, affected almost 30,000 people in Africa regularly causes major epidemics in the Sahel and sub-Sahelian regions of Africa. A truly global initiative, the consortium will combine the expertise of leading scientists from 12 centres in developed countries and 8 African partners. The consortium will work closely with WHO and the Meningitis Vaccine Project (MVP), a partnership between WHO and PATH, which is developing a vaccine to fight meningococcal disease in Africa.
The project will be managed by LSHTM, which has extensive experience in coordinating multi-centre trials in Africa, and supported by the University of Oxford, which will contribute its expertise in molecular microbiology, the Health Protection Agency, which will support serological studies and the University of Bristol, which will provide modelling and statistical support. Participating centres in Africa include Armauer Hansen Research Institute, Addis Ababa, Ethiopia; Centre de Recherche Médicale et Sanitaire, Niamey, Niger; Centre de Support de Santé, Ndjamena, Chad; Centre pour le Développement des Vaccins, Bamako, Mali; Institut de Recherche pour le Développement, Dakar, Senegal; Navrongo Health Research Centre, Navrongo, Ghana; University of Maiduguri, Maiduguri, Nigeria; WHO Multi-Disease Surveillance Centre, Ouagadougou, Burkina Faso. Each of the African partners has established links with centres in Europe (Institut Pasteur, Paris; Agence de Médecine Préventive, Paris; Institut de Médecine Tropicale du Service de Santé des Armées, Marseille; Swiss Tropical Institute, Basle; Norwegian Institute of Public Health, Oslo) or in the United States (Centers for Disease Control and Prevention, Atlanta).
Meningococcal disease is a major problem in the countries of the African Sahel and sub-Sahel - the African meningitis belt - where major epidemics occur every few years. These epidemics are not only distressing for those affected, but they necessitate the setting up of emergency treatment centres, which can cause immense disruption to health services that are already under-resourced and overstretched.
The last major epidemic, in 1996, caused at least 200,000 cases and many thousands of deaths. Most cases are seen in older children and young adults, with mortality rates during epidemics usually in the range of 5-10%. Many more people carry the infection in their throat than go on to develop serious disease – the ratio is usually in the range of one case to several hundred carriers, although this can increase during epidemics. Infection is spread from person to person through respiratory droplets, for example by sneezing.
In recent years, the impact of these epidemics has been mitigated to some extent by reactive vaccination with polysaccharide vaccines, but the widespread use of these has not reduced the frequency of epidemics. This is likely to be because these vaccines provide only short-term protection in young children, and do not prevent transmission of the infection.
It is known that conjugate vaccines, prepared by linking the capsular polysaccharide antigen of the bacterium to a protein are much more effective, but these are expensive and have not been widely used in developing countries until now. This deficit is being remedied by the Meningitis Vaccine Project which, supported by the Bill & Melinda Gates Foundation, is developing an affordable serogroup A meningococcal conjugate vaccine for use in Africa. The vaccine, which is being produced by Serum Institute of India Limited, is now in clinical trials in Africa and India. If approved for licensure, it is set to be introduced in Burkina Faso towards the end of this year, before being rolled out more widely across the African meningitis belt in subsequent years.
The African Meningococcal Carriage Consortium will seek to evaluate the impact of this new vaccine on the transmission of meningococcal infection in countries of the African meningitis belt.
Cross-sectional surveys will be undertaken in 2,000 subjects in eight target countries across the meningitis belt, once during the dry season and once during the rainy season and detailed studies of carriage will be undertaken in households where a carrier is found. These studies will determine patterns of transmission of the infection within households, risk factors for carriage and how long carriage persists, information of importance to the planning of vaccination strategies. In addition, pre- and post-vaccination surveys will be undertaken in three countries, Ethiopia, Mali and Niger, to determine the impact of vaccination on carriage. Meningococci isolated during these studies will be subjected to detailed molecular analysis to determine their relationship to each other and to meningococci found in other parts of the world.
Professor Brian Greenwood of the London School of Hygiene & Tropical Medicine, who is leading the Consortium, comments: ‘Vaccination campaigns with conjugate vaccines have been very successful in reducing the impact of meningitis in developed countries. In the UK, for example, a campaign to vaccinate against serogroup C meningococcal meningitis has had a dramatic impact on the incidence of the disease and it is highly likely that the ability of the vaccine to prevent pharyngeal carriage, and thus to interrupt transmission, played a role in its success’.
‘African countries, however, have yet to benefit from the advances that have been made in reducing the impact of this disease. Today’s announcement, the development of an effective serogroup A meningococcal conjugate vaccine, and the launch of support that this new consortium will be able to give to the vaccination programme, looks set to change this, and offers these countries real hope of a future in which epidemic meningitis is no longer the scourge it is today’.
Professor Sir Andrew Haines, Director of the London School of Hygiene & Tropical Medicine, comments: 'I am delighted that the School will be spearheading such an inspirational initiative directed towards an important but neglected public health challenge in Africa, and am grateful to all the funders for making it possible’.
For further information about the Consortium, or to interview Professor Greenwood, please contact the London School of Hygiene & Tropical Medicine Press Office on +44 (0) 207 927 2073/2802 or email lindsay.wright@lshtm.ac.uk or gemma.howe@lshtm.ac.uk.
Notes to editors:
1 WHO surveillance program. Most of these cases occurred in Burkina Faso.
2 This has been made possible by the Meningitis Vaccine Project (MVP) which was set up in 2001, with support from the Bill & Melinda Gates Foundation (http://www.meningvax.org/)
The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending over £600 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its impact on health and wellbeing. http://www.wellcome.ac.uk
