Prevalence of prolonged and chronic poliovirus excretion among persons with primary immune deficiency disorders in the Philippines

ABSTRACT

Objectives. As part of the global initiative to eradicate poliovirus infections this study aims to (1) estimate the prevalence of vaccine-derived poliovirus excretion among persons diagnosed with primary immune (B-cell or combined B/T-cell) deficiency disorders (PIDD) in the Philippines; (2) describe clinical features of these PIDD patients excreting poliovirus; (3) genetically characterize vaccine-derived polioviruses isolated from persons with PIDDs; and (4) determine the duration of poliovirus excretion among subjects who tested positive for vaccine-derived poliovirus excretion. Methods. Seventy-one (71) Filipino patients (ages 0-35 years of age) with PIDD were recruited retrospectively and prospectively over a period of 16 months. The study participants, after informed consent and administration of a questionnaire for baseline data, underwent further testing of quantitative immunoglobulin levels (IgG, IgA, and IgM) and stool poliovirus isolation using two stool samples. Stool specimens which tested positive for the poliovirus were sent to the Regional Reference Laboratory in Australia for further characterization by Intratypic Differentiation (ITD) and Vaccine-derived polioviruses (VDPV) real-time PCR. These participants were then monitored on a monthly basis until laboratory tests identified two sequential months of negative poliovirus stool specimens. Results. Seventy-one (71) patients underwent interview and quantitative serum immunoglobulin testing. However, one patient expired prior to stool isolate collection. This study, then, documented that none of the remaining 70 Filipino individuals (0-35 years old) with confirmed or suspected PIDDs chronically excreted immunodeficiency-associated vaccine-derived poliovirus (IVDPV). One patient who was a recent OPV-recipient excreted poliovirus Sabin-like 1 transiently (less than 1 month) and two patients excreted non polio-enteroviruses. Conclusions. Chronic and prolonged poliovirus excretion appears to be uncommon among Filipino patients with diagnosed Primary Immunodeficiency Disease Disorders. However, as part of the continuing global initiative for poliovirus eradication, vigilance is still necessary in patients with primary immunodeficiency diseases. Adequate identification of these patients followed by monitoring their capacity for viral excretion and environmental contamination may be necessary to achieve this goal.