Development of a molecular biology tool based algorithm to improve the diagnosis in the African Meningitis Belt

What is this project about?

This study is designed to increase the value of the MenAfriCar project, which is a large-scale effort aiming to evaluate meningococcal carriage among the population of 7 countries in the African meningitis belt: Senegal, Mali, Niger, Chad, Ghana, Nigeria and Ethiopia. In the MenAfriCar project, carriage will be measured before and after the introduction of a new meningococcal A conjugate (MenA) vaccine. Currently, a test to identify meningitis strains exists, but only for the most common disease causing strains (A, B, C, X, Y and W135). Other strains, which contribute to the complex causes of meningococcal infection in Africa, cannot be correctly identified with this test and/or other available techniques.

In this project, researchers propose to adapt the existing lab test to be more specific and test for rarer kinds of meningococci: groups H, 29E and those bacteria with no sugar coating. They will design new probes for these rarer meningococci and confirm that probes for the more common meningococcal strains work properly in bacteria isolated from Africa. Then they will optimise the new technique with known samples from the UK. The technique will be validated by testing all the samples collected during the MenAfriCar pilot studies for which results were inconclusive using existing techniques. The pilot studies collected 250 samples from each of the seven countries involved.

Why is this important?

Introduction of the new MenA vaccine in the African meningitis belt could make epidemic meningitis a thing of the past. However, we know from the introduction of MenC vaccine in the UK and other European countries that it was the vaccine’s impact on carriage and transmission of the bacteria, creating herd immunity that was key to its resounding success. The same is likely to be true for MenA, which is based on the same technology as the MenC vaccine. It is crucial to have the scientific techniques to measure carriage available in time to evaluate the impact MenA has when it is introduced.

Potential outcomes

We hope this project will enable detection of these rarer strains in the African Meningitis Belt. This work should generate a rapid, low cost and reliable way to evaluate the prevalence and incidence of meningococcal strains in the African Meningitis Belt.

Researchers also plan to improve the regular diagnostic techniques for identifying more common meningococci and to develop a good methodology for sites that do not have access to the latest technology. This project will also provide capacity building: a young African scientist will be trained in state-of-the-art molecular biological techniques. Most of the sites involved in the MenAfriCar project are reference labs for common diseases in their countries, and the network that will be created through this project will allow technical and scientific information exchanges.