Screening for long-term poliovirus excretion among children with primary immunodeficiency disorders: preparation for the polio posteradication era in Bangladesh.

BACKGROUND: Persons with primary immune deficiency disorders (PIDD) who receive oral poliovirus vaccine (OPV) may transmit immunodeficiency-associated vaccine-derived polioviruses (iVDPVs) and cause paralytic polio. The objective of this study was to identify children with PIDD in Bangladesh, and estimate the proportion with chronic poliovirus excretion. METHODS: Patients admitted at 5 teaching hospitals were screened for PIDD according to standardized clinical case definitions. PIDD was confirmed by age-specific quantitative immunoglobulin levels. Stool specimens were collected from patients with confirmed PIDD. RESULTS: From February 2011 through January 2013, approximately 96 000 children were screened, and 53 patients were identified who met the clinical case definition for PIDD. Thirteen patients (24%) had age-specific quantitative immunoglobulins results that confirmed PIDD. Of these, 9 (69%) received OPV 3-106 months before stool specimen collection. Among 11 patients, stool specimens from 1 patient tested positive for polioviruses 34 months after OPV ingestion. However, the poliovirus isolate was not available for genetic sequencing, and a subsequent stool specimen 45 days later was negative. CONCLUSIONS: The risk of chronic poliovirus excretion among children with PIDD in Bangladesh seems to be low. The national polio eradication program should incorporate strategies for screening for poliovirus excretion among patients with PIDD.

The feasibility of identifying children with primary immunodeficiency disorders: preparation for the polio post-eradication era in Bangladesh.

BACKGROUND: Persons with primary immunodeficiency disorders (PIDD) who receive oral poliovirus vaccine (OPV) or are household contacts of OPV recipients are at risk of excreting immunodeficiency-associated vaccine-derived polioviruses (iVDPVs). iVDPVs can be transmitted and cause paralytic polio. The objective of this study was to determine the feasibility of identifying infants and young children with PIDD in Bangladesh, and among those identified, to estimate the proportion excreting iVDPVs. METHODS: Patients admitted at 5 referral and teaching hospitals from the hospital catchment area were screened for PIDD using a standardized clinical case definition. PIDD was confirmed using results of testing for age-specific quantitative immunoglobulins (QIGs) levels. Stool specimens were collected according to WHO guidelines from children with confirmed PIDD. RESULTS: During February-July 2009, 13 patients were identified who met the clinical case definition for PIDD; their median age was 1.4 years (range: 2 months to 10 years). Six (46%) of the patients had age-specific QIG results that confirmed PIDD. Stool specimens from four patients tested negative for polio vaccine viruses. All four had received OPV between 50 and 264 days prior to study recruitment. CONCLUSION: Identifying children with PIDD at referral and teaching hospitals in Bangladesh is feasible, but a larger number of patients is needed to estimate the risk for iVDPV excretion. The national polio eradication program should expand surveillance for PIDD case-patients and regularly test persons with PIDD for poliovirus excretion. These efforts will be essential for developing effective prevention and control strategies following OPV cessation, especially for densely populated and tropical countries like Bangladesh where even a minimal iVDPV risk could have significant public health consequences.