Two cases have been reported both caused by vaccine derived type 2
(VDPV2). Environmental samples taken from sewage in Manila on 13 August
and a waterway in Davao on 22 August.
The first polio case was
confirmed on 14 September following testing by the National Polio
Laboratory at the Research Institute for Tropical Medicine, the Japan
National Institute of Infectious Diseases (NIID) and the United States
Centers for Disease Control and Prevention (CDC).
The case-patient is a 3-year-old girl from Lanao del Sur in the
southern Philippines. The virus isolated is genetically linked to VDPV2
previously isolated from environmental samples in Manila and Davao. This
indicates that the virus is circulating.
The second polio case
was confirmed on 19 September and is a 5-year-old boy from Laguna
Province, approximately 100 km south-east of Metro Manila.
Investigations and further characterization of the virus are ongoing.
Vaccine-derived polioviruses are forms of the poliovirus that have
genetically changed from the attenuated (weakened) virus contained in
oral polio vaccine.
