PLoS Medicine (Mar 2020)

Assessment of immunity to polio among Rohingya children in Cox's Bazar, Bangladesh, 2018: A cross-sectional survey.

  • Concepcion F Estivariz,
  • Sarah D Bennett,
  • Jacquelyn S Lickness,
  • Leora R Feldstein,
  • William C Weldon,
  • Eva Leidman,
  • Daniel C Ehlman,
  • Muhammad F H Khan,
  • Jucy M Adhikari,
  • Mainul Hasan,
  • Mallick M Billah,
  • M Steven Oberste,
  • A S M Alamgir,
  • Meerjady D Flora

DOI
https://doi.org/10.1371/journal.pmed.1003070
Journal volume & issue
Vol. 17, no. 3
p. e1003070

Abstract

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BackgroundWe performed a cross-sectional survey in April-May 2018 among Rohingya in Cox's Bazar, Bangladesh, to assess polio immunity and inform vaccination strategies.Methods and findingsRohingya children aged 1-6 years (younger group) and 7-14 years (older group) were selected using multi-stage cluster sampling in makeshift settlements and simple random sampling in Nayapara registered camp. Surveyors asked parents/caregivers if the child received any oral poliovirus vaccine (OPV) in Myanmar and, for younger children, if the child received vaccine in any of the 5 campaigns delivering bivalent OPV (serotypes 1 and 3) conducted during September 2017-April 2018 in Cox's Bazar. Dried blood spot (DBS) specimens were tested for neutralizing antibodies to poliovirus types 1, 2, and 3 in 580 younger and 297 older children. Titers ≥ 1:8 were considered protective. Among 632 children (335 aged 1-6 years, 297 aged 7-14 years) enrolled in the study in makeshift settlements, 51% were male and 89% had arrived after August 9, 2017. Among 245 children (all aged 1-6 years) enrolled in the study in Nayapara, 54% were male and 10% had arrived after August 9, 2017. Among younger children, 74% in makeshift settlements and 92% in Nayapara received >3 bivalent OPV doses in campaigns. Type 1 seroprevalence was 85% (95% CI 80%-89%) among younger children and 91% (95% CI 86%-95%) among older children in makeshift settlements, and 92% (88%-95%) among younger children in Nayapara. Type 2 seroprevalence was lower among younger children than older children in makeshift settlements (74% [95% CI 68%-79%] versus 97% [95% CI 94%-99%], p ConclusionsYounger Rohingya children had immunity gaps to all 3 polio serotypes and should be targeted by future campaigns and catch-up routine immunization. DBS collection can enhance the reliability of assessments of outbreak risk and vaccination strategy impact in emergency settings.