Laboratory surveillance for wild and vaccine-derived polioviruses - worldwide, January 2008-June 2009.

The Global Polio Laboratory Network (GPLN) isolates and characterizes polioviruses from fecal specimens of persons with acute flaccid paralysis. The network is coordinated by the World Health Organization (WHO) and includes 144 laboratories in 97 countries. Data from the network are used to guide the Global Polio Eradication Initiative by confirming polio cases, detecting and determining the origin of importations, identifying vaccine-derived polioviruses (VDPVs), and documenting the circulation of wild polioviruses (WPVs). This report updates previous reports and summarizes GPLN activities and detection of WPVs and VDPVs during January 2008-June 2009. During this period, GPLN tested 247,794 fecal samples from 127,566 acute flaccid paralysis cases, from which 14,279 (5.8%) poliovirus isolates (vaccine-related and WPV) were detected, including 4,280 (1.7%) WPVs from 22 countries. GPLN laboratory capacity and capabilities remain an integral part of surveillance for polioviruses and efforts to eliminate polio from the remaining areas of circulation.