Abstract:
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.
