Importation and Circulation of Vaccine-Derived Poliovirus Serotype 2, Senegal, 2020–2021 |
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| Authors: | Martin Faye,Ousmane Ké bé ,Boly Diop,NDack Ndiaye,Annick Dosseh,Abdoulaye Sam,Aliou Diallo,Hamet Dia,Jean Pierre Diallo,Ndongo Dia,Davy Evrard Kiori,Ousmane Madiagne Diop,Amadou Alpha Sall,Ousmane Faye |
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| Affiliation: | Institut Pasteur de Dakar, Dakar, Senegal (M. Faye, O. Kébé, H. Dia, N. Dia, D.E. Kiori, A.A. Sall, O. Faye);Ministry of Health and Social Actions, Dakar (B. Diop, A. Sam, J.P. Diallo);World Health Organization Inter-Country Support Team for Western Africa, Ouagadougou, Burkina Faso (A. Dosseh);World Health Organization Senegal Country Office, Dakar (A. Diallo);World Health Organization, Geneva, Switzerland (O.M. Diop) |
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| Abstract: | Environmental surveillance for poliovirus is increasingly used in poliovirus eradication efforts as a supplement to acute flaccid paralysis (AFP) surveillance. Environmental surveillance was officially established in 2017 in Senegal, where no poliovirus had been detected since 2010. We tested sewage samples from 2 sites in Dakar monthly for polioviruses. We identified a vaccine-derived poliovirus serotype 2 on January 19, 2021, from a sample collected on December 24, 2020; by December 31, 2021, we had detected 70 vaccine-derived poliovirus serotype 2 isolates circulating in 7 of 14 regions in Senegal. Sources included 18 AFP cases, 20 direct contacts, 17 contacts in the community, and 15 sewage samples. Phylogenetic analysis revealed the circulation of 2 clusters and provided evidence on the virus introduction from Guinea. Because novel oral polio vaccine serotype 2 was used for response activities throughout Senegal, we recommend expanding environmental surveillance into other regions. |
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| Keywords: | polio vaccine-derived poliovirus serotype 2 viruses environmental surveillance acute flaccid paralysis Senegal |
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