Meningitis outbreak in Niger is an urgent warning

Abstract

In most regards, the meningitis epidemic that struck Niger earlier this year was not unusual. It hit in March, the peak of the meningitis season, a period of dry weather and cold evenings ideal for transmission of the disease. The Ministry of Public Health recorded about 8500 cases, and 573 deaths up till June 28, 2015 a sizeable but not unprecedented outbreak—the 1996 epidemic killed roughly 12 000 people in neighbouring Nigeria. But the 1996 outbreak was caused by the group A meningococcus, historically responsible for more than 90% of epidemic meningitis in sub-Saharan Africa. The outbreak in Niger was caused by a new strain of meningitis C. Serogroup C had been thought only to be a serious problem in western Europe and the USA. Its involvement in an African epidemic has prompted WHO and partners including MSF and UNICEF to issue a joint warning that the continent must prepare for the possibility of a destructive outbreak over the 2016 meningitis season. The partners added that “an acute shortage of meningitis C containing vaccine threatens to severely limit the world’s ability to minimise the number of people aff ected”. Niger lies in the middle of the meningitis belt, which stretches from Senegal to Ethiopia, a region of roughly 300 million people. Niger is hyperendemic for the disease, and was one of the first countries to receive the Serum Institute’s meningococcal A conjugate vaccine after it began its rollout across the meningitis belt in 2010. More than 217 million people in sub-Saharan Africa have now been vaccinated against meningitis A; the continent has not seen a major outbreak of the disease since 2009. But the vaccine does not offer protection against meningitis C. For protection against the C serogroup, there are two options. The older polysaccharide vaccines only confer immunity for 2–3 years, and are not eff ective in very young children. Their production has dwindled since the advent of conjugate vaccines and they are now largely reserved for use in emergencies (more than 1 million doses were mobilised to combat the Niger outbreak). “The conjugate vaccines can be taken in infancy, off er a higher and better antibody response,