Meningitis in Africa: Hundreds of thousands vaccinated
16 March 2007 | Geneva - Two months into the dry season in the African "meningitis belt",15 595 cases, including 1670 deaths, have been reported to WHO from four countries: Burkina Faso, the Democratic Republic of the Congo, Sudan and Uganda. Two of these countries, Uganda and the Democratic Republic of the Congo, are at the extreme south of the belt, The region stretches from Senegal in the west to Ethiopia in the east, an area with a population of 300 million. The samples show that these cases are caused by Neisseria meningitidis serogroup A, the most common serogroup in Africa.
In northern Uganda, 2961 cases, including 105 deaths, have been reported. A vaccination campaign has been completed in some areas and is continuing in others. WHO and Médecins sans Frontières (MSF) are working together to contain the outbreak.
In southern Sudan, 6946 cases (430 deaths) have been reported from nine out of 10 states. In Burkina Faso, 4958 cases (432 deaths) were reported. In the Democratic Republic of the Congo, 730 cases (84 deaths) have been reported.
The International Coordinating Group (ICG*) on Vaccine Provision for Epidemic Meningitis has so far released 1.1 million vaccine doses to respond to the outbreak in Sudan and is ready to provide additional doses if needed. Around 1.5 million people in the affected counties have been targeted in mass vaccination campaigns organized by national authorities, WHO, MSF, International Medical Services, and local NGOs, and supported by UNICEF, UN Office for the Coordination of Humanitarian Affairs (OCHA) and the European Community Humanitarian Office (ECHO). The affected areas are known to host large numbers of returnees, as well as displaced populations living in areas not easily accessible and dispersed population settlements.
Vaccination campaigns are going on in Burkina Faso, where the ICG has already released 530 000 doses. WHO is present in the field in all the affected countries, assisting with surveillance and control measures. WHO and its partners have provided drugs for case management, emergency supplies for outbreak investigation and technical guidance for outbreak control and management.
In the African meningitis belt, improved epidemiological surveillance and prompt case management with oily chloramphenicol - the standard antibiotic treatment - are used to control epidemics. At the same time, WHO and its partners recommend reactive mass vaccinations targeted at the highest risk groups: usually people between the ages of 2 and 30 years. Every district that is in an epidemic phase, and adjoining districts that are in the alert phase should be targeted for vaccination. It is estimated that a mass immunization campaign, promptly implemented, can prevent 70% of cases.
This season, the ICG secured some 8 million doses as an emergency stockpile, out of which 5.5 million are currently available. Despite concerns about a shortage of vaccine, WHO estimates some 15 million doses are still available in the market, which countries can purchase. Furthermore, to rapidly address the potential shortage of vaccine supply, WHO decided to assess the status and production capacity of polysaccharide manufactures worldwide. One manufacturer, Bio-Manguinhos in Brazil, was identified as the strongest and quickest alternative for scaling-up vaccine supply in the short and medium term. In partnership with the Finlay Institute in Cuba, Bio-Manguinhos is working with WHO to ensure a supply of up to 10 million doses of bivalent AC meningitis vaccine by the next epidemic season.
Meningitis is an infection of the meninges, the thin lining that surrounds the brain and the spinal cord. Several different bacteria can cause meningitis. Neisseria meningitidis is one of the most important because of its potential to cause large epidemics. Meningococcal disease was first described in 1805 when an outbreak swept through Geneva, Switzerland.
The bacteria are transmitted from person to person through droplets of respiratory or throat secretions. Close and prolonged contact, e.g. kissing, sneezing and coughing on someone, living in close quarters or dormitories (military recruits, students), sharing eating or drinking utensils etc. facilitate the spread of the disease. The average incubation period is four days, ranging between two and 10 days. N. meningitidis only infects humans; there is no animal reservoir.
The most common symptoms are stiff neck, high fever, sensitivity to light, confusion, headache and vomiting. Even when the disease is diagnosed early and adequate therapy instituted, 5% to 10% of patients die, typically within 24-48 hours of onset of symptoms. Meningococcal disease is potentially fatal and should be viewed as a medical emergency. A range of antibiotics may be used for treatment.
The highest burden of meningococcal disease occurs in sub-Saharan Africa, which is known as the “meningitis belt”. This hyperendemic area is characterized by particular climate and social habits. During the dry season (December to June), because of dust winds and upper respiratory tract infections due to cold nights. The transmission of N. meningitidis is facilitated by overcrowded housing at family level and by large population displacements due to pilgrimages and traditional markets at regional level.
WHO promotes a two-pronged strategy which involves epidemic preparedness and epidemic response. Preparedness focuses on surveillance, from case detection and investigation and laboratory confirmation. Epidemic response entails a prompt and appropriate case management as well as timely reactive mass vaccination.
An improved and affordable conjugate vaccine is expected by 2010. It will offer longer lasting protection, allowing preventive immunization. WHO supports the development of such a vaccine through the Meningitis Vaccine Project, a partnership between the Program for Appropriate Technology in Health (PATH) and WHO.
* Following large meningitis outbreaks in Africa in 1995-96, WHO was instrumental in establishing the International Coordinating Group (ICG) on Vaccine Provision for Epidemic Meningitis Control to ensure rapid and equal access to vaccines and injection material as well as for their adequate use when the stocks are limited. The ICG is composed of WHO, UNICEF, MSF and the International Federation of the Red Cross and Red Crescent Societies.
For further information, please contact:
Dr Eric Bertherat
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Tel.: +41 22 791 32 28
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