Emergence of Vaccine-derived Polioviruses, Democratic Republic of Congo, 2004–2

Emerging Infectious Diseases
Volume 19, Number 10—October 2013

Emergence of Vaccine-derived Polioviruses, Democratic Republic of Congo, 2004–2011
Nicksy Gumede , Olivia Lentsoane, Cara C. Burns, Mark Pallansch, Esther de Gourville, Riziki Yogolelo, Jean Jacques Muyembe-Tamfum, Adrian Puren, Barry D. Schoub, and Marietjie Venter
Author affiliations: National Institute for Communicable Diseases, Johannesburg, South Africa (N. Gumede, O. Lentsoane, A. Puren, B.D. Schoub, M. Venter); University of Witwatersrand, Johannesburg (N. Gumede, B.D. Schoub); University of Pretoria, Pretoria, South Africa (M. Venter); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (C.C. Burns, M. Pallansch); World Health Organization, Geneva, Switzerland (E. de Gourville); National Institute for Biomedical Research, Kinshasa/Gombe, Democratic Republic of Congo (R. Yogolelo, J.J. Muyembe-Tamfum)

Polioviruses isolated from 70 acute flaccid paralysis patients from the Democratic Republic of Congo (DRC) during 2004–2011 were characterized and found to be vaccine-derived type 2 polioviruses (VDPV2s). Partial genomic sequencing of the isolates revealed nucleotide sequence divergence of up to 3.5% in the viral protein 1 capsid region of the viral genome relative to the Sabin vaccine strain. Genetic analysis identified at least 7 circulating lineages localized to specific geographic regions. Multiple independent events of VDPV2 emergence occurred throughout DRC during this 7-year period. During 2010–2011, VDPV2 circulation in eastern DRC occurred in an area distinct from that of wild poliovirus circulation, whereas VDPV2 circulation in the southwestern part of DRC (in Kasai Occidental) occurred within the larger region of wild poliovirus circulation.