Poliovirus neutralizing antibody levels among individuals in three regions of Ghana

Abstract

Introduction: Ghana was declared polio-free in 2015 after the last polio case in 2008. We determined the poliovirus neutralizing antibody levels among individuals to identify possible immunity gaps.

Methods: A cross-sectional, hospital-based study was undertaken in Northern, Ashanti and Greater Accra regions of Ghana. Individuals referred for haematology at the teaching hospitals’ laboratories were invited to participate in our study. Neutralizing-antibody titers to poliovirus serotypes 1,2 & 3 were assayed by WHO-standards. Antibody titers of ≥8 were considered protective. Bivariate and multivariate analyses were conducted on subject characteristics to assess potential factors for failure to seroconvert. P-values < 0.05 were considered statistically significant.

Results: Poliovirus (PV) neutralizing-antibody serotypes 1, 2 and 3 were detected in 86.0% (264/307), 84% (258/307) and 75% (230/307) of samples respectively. 60.1% (185/307) were seropositive for the three poliovirus serotypes. Neutralizing poliovirus antibodies for PV1 and PV2 were higher than for PV3. Seroprevalence of poliovirus-neutralizing
antibodies among males (PV1=51.9%, PV2= 51.6% and PV3= 52.6%) were higher than in females. Seroprevalence rates of poliovirus-neutralizing antibodies (PV1, PV2, and PV3) were highest in the Northern region (90%, 81%, and 77%). Poliovirus neutralizing-antibodies (PV1and PV2) decreased with age [p< 0.001]. Low seroprevalence of
poliovirus-neutralizing antibodies was significantly associated with low school attendance of mothers (p<0.001).

Conclusion: Our study population has some protection from polio. However, immunity appears to be lower with a higher age or low Mother’s education. This may suggest the need for young-adult booster-dose to minimize the risk of wild poliovirus infection.

Keywords: poliomyelitis, seroprevalence, neutralizing antibodies, polio-immunity, Ghana

Funding: WHO Country Office Ghana.