Background:
Neisseria meningitidis remains a public health concern in Ghana and across the
African meningitis belt, particularly with the periodic changes of serogroup.
Deciphering the patterns and circulating serogroups is significant for vaccine policy
and outbreak preparedness.
Methods:
A retrospective analysis of 295 cerebrospinal fluid (CSF) samples collected between
2016 and 2020 across six regions of Northern Ghana. Laboratory-confirmed
meningococcal cases were serogroup using RT-PCR. Distribution of Serogroup were
analysed by year and region, and associations were assessed using chi square test.
Results and Discussion:
A total of 295 confirmed meningococcal cases were included in the analysis. The
proportion of serogroup W (NmW), serogroup X (NmX), serogroup B (NmB) and
serogroup C (NmC) across the four years were; 61.4% (181/295), 36.3% (107/295),
0.7% (2/295), and 0.3% (1/295) respectively. With four cases 1.4% being
indeterminate. In 2016, serogroup W (NmW) predominated accounting for 97.8% of
92 cases, whilst serogroup X (NmX), serogroup B (NmB) and serogroup C (NmC)
constituted 1.1%, 0%, and 1.1% respectively. However, NmW dominance declined
over time and was replaced by serogroup X (NmX) in subsequent years, with NmX
becoming the leading serogroup in 2020 accounting for 85.7% (66/77) of the cases.
The shift in serogroup distribution was highly significant over the years (p < 0.001)
and differed significantly by regions (p < 0.001). NmW remained concentrated in
Northern region 59.7% (108/181) while NmX predominated in upper East 44.9%
(48/107) and West 42.1% (45/107) regions. No statistically significant associations
were observed between serogroup and age group or sex.
Conclusions:
The findings highlight a rapid and region dependent replacement of NmW by NmX
within a four year period. This epidemiological serogroup changes calls for
continuous surveillance and showcases the public health relevance of NmX. These
data provide critical evidence to inform regional preparedness strategies and future
vaccine development and implementation.