Trends of Reported Cerebrospinal Meningitis in the Upper West Region Three Years Post-Introduction of the Conjugate Vaccine in Ghana

Abstract

Background: Cerebrospinal meningitis is a public health burden in Ghana and can cause mortality up to 10% annually. About 20% of those who survive cerebrospinal meningitis suffer permanent sequelae. The plain polysaccharide vaccine was therefore introduced to prevent the disease. Unfortunately, the vaccine lacked T-cell involvement and worked poorly in children and could not generate secondary response in adults. The licensure of the conjugate vaccine seemed to reduce cases of CSM across the meningitis belt. However, the rates and dynamics of carriage across the meningitis belt remains poorly understood unlike carriage in high-income countries. The General Objective of this study is to assess the trends of CSM before and after the introduction of the conjugate vaccine in the Upper West Region of Northern Ghana. The study also specifically seeks to determine any short term shift in age group distribution of CSM cases in the region and also to determine any short term change in strains of Neisseria meningitdis isolated in Northern Ghana. Methodology: A pre-tested data abstraction form was used to abstract patients information from case-based records kept at the Upper West Regional Disease Control Unit three years pre-(2010-2012) and three years’ post(2013-2015) introduction of the conjugate vaccine in the region. Data were analyzed using STATA version 13 using the mid-year populations of the region as denominators. Results: From 2010-2012, out of 688 reported cases of CSM, there were 226 confirmed cases. Among the confirmed cases, males comprised 112 and females 114. Out of the 688 reported cases, 49 of them died .Three years after the introduction of the conjugate vaccine, there was a decline in the number of reported cases. The totalnumber of cases for this period was 461 out of which 72 were confirmed cases. Among the reported cases there were 34 males and 38 females. Forty-nine patients died within the same period as result of the disease. Children below 5 years of age were most hit. The bacterium Neisseria meningitidis and its strains especially N.m W135 and N.m Y were responsible for most of the cases in the region. The study has shown a significant reduction of CSM cases in all age groups of over 50% after the introduction of the vaccine. Children below 5 years of age and adults 20 years and above were the most hit groups in both periods. It was also found out that the bacterium Neisseria meningitides and its associated strain N.m W135 were responsible for majority of the cases and caused death rates higher than the usual death rates in the region. CONCLUSION: Although the introduction of the conjugate vaccine led to a decline in new cases of meningitis in Northern Ghana indicating possible effectiveness of the vaccine, the fact that there still were annual outbreaks of CSM cases in the North provides evidence that the vaccine is not 100% protective against meningitis.