Poliovirus Excretion among Persons with Primary Immune Deficiency Disorders: Summary of Data from Enhanced Poliovirus Surveillance in Egypt, 2011-2014

Abstract

Background: If exposed to oral poliovirus vaccine (OPV), persons with primary immune deficiency disorders (PID) are at increased risk of paralytic poliomyelitis; and can chronically excrete poliovirus. However, the risk of excretion of vaccine derived poliovirus among immunodeficient persons (iVDPV) is not well characterized. We present summary of data from poliovirus surveillance project among PID patients collected between 2011 and 2014 from 11 Egyptian Governorates. Methods: Stool was tested for polioviruses in suspected or confirmed PID children regardless of whether Acute Flaccid Paralysis (AFP) was present or not. Those excreting poliovirus were followed until three consecutive negative stool samples were obtained. Results: There were 122 patients with suspected or confirmed PID identified; 13/122 (11%) excreted poliovirus; of these, 6 excreted iVDPVs, the remaining 7 excreted Sabin virus. The duration of iVDPV excretion ranged from 1 to 21 months. AFP was detected in 3/6 (50%) of those excreting iVDPVs. All iVDPV excretors had history of receiving OPV. Conclusions: Chronic poliovirus excretion in PID patients is rare, however, poliovirus eradication requires removal of all polioviruses from circulation; and because PID individuals are not necessarily paralyzed they might be missed by current poliovirus surveillance based on detection of AFP. To achieve poliovirus eradication, surveillance for polioviruses among PID patients should be routinely conducted in all countries, and poliovirus antiviral therapy must be made available for those with chronic excretion.