Virologie: Aktuelle Forschung

Environmental Surveillance for Poliovirus in Greater Accra and Eastern Regions of Ghana-2016

Abstract

Odoom JK *,Obodai E ,Diamenu S ,Ahove V ,Addo J ,Banahene B ,Taylor J ,Asante-Ntim NA ,Attiku KO ,Dogbe M ,Kaluwa O

Introduction: As the Global Polio Eradication Initiative (GPEI) moves towards achieving the goal of polio eradication, environmental surveillance which investigates polio virus in sewage or wastewater, plays a major role in providing evidence for certification of polio-free status. Many countries in the AFRO region have added environmental surveillance to acute flaccid paralysis (AFP) surveillance but Ghana is yet to adopt and conduct environmental surveillance as a routine national activity. Here, we piloted environmental surveillance from September to December 2016 to determine silent circulation of poliovirus in some districts within Greater Accra and Eastern regions.

Objective: The study aimed to test national capacity and preparedness to undertake environmental surveillance as part of routine national surveillance activity for poliovirus.

Methods: Sewage samples collected from six selected sites within two regions were processed by grab method according to World Health Organization (WHO) guidelines on environmental surveillance. The samples were concentrated and inoculated on RD and L20B cell lines for virus isolation. Virus isolates were subjected to real-time PCR and non-polio enterovirus (NPEVs) typing.

Results: From a total of 36 sewage samples collected from the six sites, 7 (19.4%) were positive on cell lines. Of these positives, 6 (85.7%) showed growth on RD cells only and 1(14.2%) showed growth on both RD and L20B. The isolates were identified as one Coxsackie virus A 16 belonging to human enterovirus (HEV) A group, two Echovirus 6 and one each of Echovirus 13 and Echovirus 29 of HEV B, and Coxsackie virus 24 of HEV C.

Conclusion: No wild poliovirus transmission was detected in the study samples however, 7 NPEVs were isolated from 50% of the sites. Although the study in Ghana was not geographically representative, results were consistent with the enteroviruses distribution in AFP cases in the country. Our findings also indicated that environmental surveillance is feasible in Ghana and can be implemented as routine national surveillance program based on available national capacity and experience.