Polivirus Antibody and Lameness among Individuals in the Three regions ogf Ghana

Abstract

Introduction: In 2008, Ghana recorded the last case of poliomyelitis or polio and the causative agent was the wild polio virus. The country has been certified free of polio and it is at the verge of polio eradication. High levels of polio neutralizing antibodies (immunity) must be maintained to prevent the importation of wild poliovirus. We determined the seroprevalence of polio viruses (P1, P2, and P3) antibodies and the risk factors for seronegativity in Greater Accra, Ashanti and Northern regions of Ghana in order to identify any gaps for system improvement. Methods: A cross-sectional, hospital-based seroprevalence study supplemented by a school lameness survey was undertaken in the three study regions in 2016. Individuals, who visited the three teaching hospitals of the regions and needed to give out blood samples for laboratory investigation, were invited to partake in the survey. Micro-neutralization test for poliovirus serotypes, 1, 2 and 3 antibodies was performed following WHO-standard procedures. Antibody titers of ≥ 1:8 were considered positive. Bivariate and multivariate analyses were conducted on subject characteristics to assess for potential factors for failure to sero-convert. Statistical significance was set at P -values <0.05 In the school lameness survey, clinical and epidemiological data were obtained from parents and their lamed children using a semi-structured questionnaire in the same three regions. School lameness data was descriptively analysed by person, place and time by employing frequency distributions, percentages, means, standard deviation and rates. Data was analysed using STATA version 13. Results: Neutralizing-antibodies against poliovirus types 1, 2 and 3 were detected in 86.0% (264/307), 84% (258/307) and 75% (230/307) of samples respectively. Overall, 60.1% (185/307) were seropositive and 2.9% (9/307) were seronegative for the three polio serotypes. Seroprevalence of polio-neutralizing antibodies among males (P1=51.9%, P2=51.6% and P3=52.6%) were higher than females. Seroprevalence rates of polio neutralizing antibodies (P1, P2 and P3) were highest in the Northern Region (91.8%, 82.4%, and 77.4%). Polio neutralizing-antibodies (P1 and P2) decreased with age [p<0.001]. Low seroprevalence of polio-neutralizing antibodies was significantly associated with low school attendance of mothers [p=0.003 for PV1 and p<0.001 for PV2]. Prevalence of residual paralysis was 0.58/1,000 or 5.8/10,000 children aged 0-15years in schools of the study regions. Conclusion: This study revealed a moderate level of seroprevalence of neutralizing antibodies to the three polio serotypes with some regional differences. Seropositivity was generally low with increasing age and the mother’s education level was crucial to seronegativity. The drastic reduction of paralytic poliomyelitis may be attributed to the moderate level of polio-neutralizing antibodies. To further strengthen the gains made in polio eradication, the Ghanaian government needs to increase and sustain budgetary allocation on polio eradication awareness and mass immunizations. The Expanded Programme on Immunization (EPI), Ghana, may consider young-adult booster-dose of polio vaccine, introduce inactivated polio vaccine (IPV) to supplement the oral polio vaccine and conduct a nationwide seroprevalence and community based lameness survey to gauge programme performance. Female child education and career counseling for Junior High School pupils and those older may be intensified by all District Assemblies and by churches