In a study funded by Meningitis Research Foundation, researchers have developed state of the art tests and a simple, accurate and standardised protocol to identify strains of meningococcal meningitis.
These tests and protocols are specially tailored for use in laboratories in the meningitis belt, a region of Sub-Saharan Africa with the highest incidence of meningococcal disease in the world.
Meningococcal bacteria are carried in the noses and throats of some people and to most they are harmless. However the bacteria can be spread from person to person and more rarely, can invade the body and cause meningitis or septicaemia.
Some vaccines that protect people against meningococcal disease can also stop a person from carrying the bacteria too, which reduces spread of the bacteria to others in the population. Reducing this carriage is the best way to protect whole populations.
Conventional methods used to detect meningococcal disease bacteria are complex, long and tend to be susceptible to errors.
The new approach, identified in the study by Dr Olivier Manigart and Prof Martin Maiden et al, Development of a PCR algorithm to detect and characterize Neisseria meningitidis carriage isolates in the African meningitis belt, significantly reduced the need for repetitive testing, and proved highly effective at rapidly detecting all groups of meningococcal bacteria - including meningococcal E, H and Z - for which there had not previously been tests available for.
After a century of huge epidemics of meningococcal A meningitis (MenA) in the African meningitis belt countries, causing devastation amongst communities and incapacitating health services, an affordable vaccine was developed against MenA.
Since 2010, 300 million people have been vaccinated leading to substantial reductions in the incidence of MenA in the meningitis belt. The protocol and tests developed in this project were used to demonstrate the impact of the vaccine on transmission of meningococcal bacteria within families and populations.
However epidemics due to MenW, MenC and MenX continue and it remains important to continue strengthening surveillance to monitor all types of meningococcal bacteria that are circulating among populations in the meningitis belt.
A new pentavalent vaccine is currently in development that could be the first to protect people for several years against five types of meningococcal disease, meningococcal A, C, W, Y and X.
Once that is licenced and introduced into countries immunisation schedules, studies will be needed to assess how well it’s preventing carriage and transmission of the bacteria. The new protocol researchers have developed will help enormously to evaluate the MenACWYX vaccine.
The work described in this study, together with another study by the same researchers, Alternative Molecular Methods for Improved Detection of Meningococcal Carriage and Measurement of Bacterial Density, improved carriage detection by 240%.