Emergence and control of epidemic meningococcal meningitis in sub-Saharan Africa

Abstract

For more than a century, meningitis epidemics have regularly recurred across sub-Saharan Africa, involving 19 contiguous countries that constitute a 'meningitis belt' where historically the causative agent has been serogroup A meningococcus. Attempts to control epidemic meningococcal meningitis in Africa by vaccination with meningococcal polysaccharide (PS) vaccines have not been successful. This is largely because PS vaccines are poorly immunogenic in young children, do not induce immunological memory, and have little or no effect on the pharyngeal carriage. Meningococcal PS-protein conjugate vaccines overcome these deficiencies. Conjugate meningococcal vaccine against serotype A (MenAfriVac) was developed between 2001 and 2009 and deployed in 2010. So far, 262 million individuals have been immunized across the meningitis belt. The public health benefits of MenAfriVac have already been demonstrated by a sharp decline in reported cases of meningococcal disease in the countries where it has been introduced. However, serogroup replacement following mass meningitis vaccination has been noted, and in 2015 an epidemic with a novel strain of serogroup C was recorded in Niger and Nigeria for the first time since 1975. This has posed a serious challenge toward elimination of meningococcal meningitis epidemics in the African. For an effective control of meningococcal meningitis in the African meningitis belt, there is a need for an effective surveillance system, provision of rapid antigen detection kits as well as affordable vaccine that provides protection against the main serogroups causing meningitis in the sub-region.

Non-typhoidal Salmonella bloodstream infections in Kisantu, DR Congo: Emergence of O5-negative Salmonella Typhimurium and extensive drug resistance

“…As this report shows rapid changes in serotype distribution, multivalent vaccines are needed. The risk for serotype replacement after vaccine introduction, as known from streptococci [72] and meningococci [73], is real and vigilant monitoring of NTS-serotypes is warranted. Furthermore, the absence of the O5-epitope can impact vaccine immunogenicity of this strain.…”

Case-by-Case Surveillance for Bacterial Meningitis in Benin: Data Analysis, 2016 to 2018

“…Investments in prevention (introduction of new polysaccharide and conjugate vaccines) of bacterial meningitis over the last decade are justified by this improvement in morbidity and mortality [21]. The implementation of robust immunization programs and high-quality clinical care has contributed significantly to reducing the burden of disease in the region [22]. Benin is subdivided into 12 departments.…”

Nervous System Infections and the Global Traveler

“…48 A novel strain of serogroup C emerged in Niger and Nigeria from 2013 to 2015 for the first time since 1975, displaying evidence of serogroup replacement. 49 Additionally, the prevalence of serogroup W has increased in Niger and Burkina Faso following the mass vaccination against serogroup A in 2010. 49 Serogroup X also raises a large concern because the incidence has been increasing and there is no vaccine available currently.…”

“…49 Additionally, the prevalence of serogroup W has increased in Niger and Burkina Faso following the mass vaccination against serogroup A in 2010. 49 Serogroup X also raises a large concern because the incidence has been increasing and there is no vaccine available currently. 50 Individuals traveling to regions within the meningitis belt should be aware of the heightened risk of contracting bacterial meningitis during the dry season (December-June) due to increased nasopharyngeal mucosa damage from dusty conditions, cold nights, and frequent upper respiratory infections.…”