Published Date: 2008-01-25 11:00:15
Subject: PRO/EDR> Meningitis, meningococcal - Africa: W. Africa, Congo DR
Archive Number: 20080125.0309
MENINGITIS, MENINGOCOCCAL - AFRICA: WEST AFRICA (BURKINA FASO,
NIGERIA, NIGER), CONGO DR
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Thu 17 Jan 2008
From: AllAfrica, IRIN (UN Integrated Regional Information Networks)
The World Health Organization (WHO) has confirmed outbreaks of the
deadly meningitis bacterium [_Neisseria meningitidis_] in 3 West
African countries, marking the start of what experts have warned
might be the worst meningitis epidemic to hit Africa in a decade.
"One district is on alert in Burkina Faso, an epidemic has been
reported in a region of Nigeria, and there are 2 cases in Niger, as
well as cases in the Democratic Republic of Congo," Professor Kader
Konde, director of WHO's Ouagadougou [the capital of Burkina
Faso]-based Multi-Disease Surveillance Centre (MDSC) told IRIN
[Integrated Regional Information Networks, commonly known as IRIN, is
a project of the United Nations Office for the Coordination of
The WHO warned in October  that 80 million people out of
roughly 350 million who live in 21 African countries stretching from
Ethiopia in the east to Mauritania in the west might need to be
vaccinated against the bacterium [_Neisseria meningitidis] this year
. Meningococcal meningitis, which usually reaches epidemic
levels in the region often referred to as Africa's "meningitis belt"
between December and May, could be especially severe this year 
as the region is heading toward the peak of a 10- to 12-year cycle of
meningitis crises, health forecasters say.
Between 1995 and 1997, the last time there was a major epidemic in
the region, at least 25 000 people died and 250 000 people were
infected. From December 2006 to May 2007, 53 000 cases of meningitis
were reported and an estimated 4000 people died across the region.
Semi-arid Sahelian countries are hit each year by outbreaks during
the dry seasons between December and June when strong, dust-laden
winds and cold nights make people more prone to respiratory
infections. The meningitis bacterium is transmitted by sneezing or
coughing. According to Konde, the situation could be worse this year
 because of high dust levels in the region and the low level of
immunity among populations. He said new research by WHO and national
research centres also appears to have shown a new strain of the
bacterium. "If you take into account all these factors we find
ourselves in a situation where the risk [of epidemics] is high," Konde said.
Preparedness for meningitis epidemics is notoriously difficult
because vaccines cannot be administered until it is known which of
the many different forms of the bacterium are spreading. In
2006-2007, the humanitarian response was further hindered by a
shortfall of the cheaper vaccines usually used in the region as
European producers focused on producing newer, longer-lasting but
more expensive vaccines. Just 7 million doses were available. In
2008, between 25 million and 30 million doses could be available,
according to WHO. "We do find ourselves in a more favourable
situation than last year ," Konde said.
Emergency health officials are due to meet in Dakar next week [21-27
Jan 2008] to coordinate responses to the expected epidemic. Hans
Hebbing, regional health coordinator of the International Federation
of the Red Cross, told IRIN the Federation has already started
training 25 000 volunteers across the region, and is educating people
about how to recognise meningitis and the dangers. "We know this is
not really going to prevent a major outbreak. But we're hoping that
early activity can prevent some spread of the disease and we do know
that training and preparedness can make the response faster," he said.
Meningitis is an infection of the thin lining around the brain and
spinal cord. Even when meningitis is diagnosed early and adequate
therapy is available, between 5 and 10 percent of patients die,
typically within 24 and 48 hours of experiencing the 1st symptoms.
Many thousands of survivors are left with brain damage, hearing loss,
or learning disabilities.
[Meningitis due to the _Neisseria meningitidis_ occurs both
sporadically and as epidemics. There are at least 13 serogroups,
based on the antigenic specificity of their capsular polysaccharides;
disease due serogroups A, B, C, Y, and W135 are most common. All
serogroup polysaccharides but B, are immunogenic in humans.
From a prior ProMED-mail post (20071207.3954): To control an
outbreak, WHO recommends mass vaccination with the appropriate
vaccine, depending availability, in every involved district in an
attempt to induce herd immunity (whereby transmission is blocked when
a critical percentage of the population have been vaccinated
There are several different types of meningococcal vaccines.
Polysaccharide vaccines, which have been available for more than 30
years, exist against serogroups A, C, Y, and W-135 in various
combinations (such as, a bivalent AC, trivalent ACW-135, and a
tetravalent ACYW-135 polysaccharide vaccine). There is a monovalent
conjugate vaccine against serogroup C and a tetravalent against
serogroups A, C, Y, and W-135. The conjugate vaccines are immunogenic
for children under 2 years of age whereas polysaccharide vaccines are
not. All these vaccines have been proven safe and effective with
infrequent and mild side effects. For both the meningococcal
conjugate and the polysaccharide vaccines, approximately 7-10 days
are required following vaccination for development of protective
levels of anti-meningococcal antibodies.
During the 1st 10 weeks of the 2006 meningitis season, outbreaks in
eastern Africa were mainly caused by _Neisseria meningitidis_
serogroup W-135, whereas in West Africa the outbreak was due to
mainly serogroup A. The serogroups currently spreading in sub-Saharan
Africa are not stated in the news release above.
For a map of the African meningitis belt, see
(<http://wwwn.cdc.gov/travel/yellowBookCh4-Menin.aspx>). - Mod.ML]