Modeling the spread of polio in an IPV-vaccinated population: lessons learned from the 2013 silent outbreak in southern Israel

BMC Medicine

Research Article

O. Mor¹  M. Weil¹  E. Kopel¹  L. Shulman¹  Y. Manor¹  E. Anis¹  R. Singer¹  Rami Yaari²  Amit Huppert³  Danit Sofer⁴  Ella Mendelson⁵  Guy Katriel⁶  Elizabeth Miller⁷  Ehud Kaliner⁸  Itamar Grotto⁹  Jacob Moran-Gilad⁹ 

[1] Bio-statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research, Chaim Sheba Medical Center, 52621, Tel Hashomer, Israel;Bio-statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research, Chaim Sheba Medical Center, 52621, Tel Hashomer, Israel;Biomathematics Unit, Department of Zoology, Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel;Bio-statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research, Chaim Sheba Medical Center, 52621, Tel Hashomer, Israel;School of Public Health, the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel;Central Virology Laboratory, Ministry of Health, Chaim Sheba Medical Center, Tel Hashomer, Israel;Central Virology Laboratory, Ministry of Health, Chaim Sheba Medical Center, Tel Hashomer, Israel;School of Public Health, the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel;Department of Mathematics, ORT Braude College, Karmiel, Israel;Public Health England Immunisation, Hepatitis and Blood Safety Department, 61, Colindale Avenue, London, UK;School of Public Health, the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel;Public Health Services, Ministry of Health, Jerusalem, Israel;Public Health Services, Ministry of Health, Jerusalem, Israel;Faculty for Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel;

关键词: Polio;    Inactivated polio vaccine;    Oral polio vaccine;    Transmission model;    Model fitting;    Vaccination strategies;   

DOI  :  10.1186/s12916-016-0637-z

 received in 2015-12-18, accepted in 2016-06-09,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundPolio eradication is an extraordinary globally coordinated health program in terms of its magnitude and reach, leading to the elimination of wild poliovirus (WPV) in most parts of the world. In 2013, a silent outbreak of WPV was detected in Israel, a country using an inactivated polio vaccine (IPV) exclusively since 2005. The outbreak was detected using environmental surveillance (ES) of sewage reservoirs. Stool surveys indicated the outbreak to be restricted mainly to children under the age of 10 in the Bedouin population of southern Israel. In order to curtail the outbreak, a nationwide vaccination campaign using oral polio vaccine (OPV) was conducted, targeting all children under 10.MethodsA transmission model, fitted to the results of the stool surveys, with additional conditions set by the ES measurements, was used to evaluate the prevalence of WPV in Bedouin children and the effectiveness of the vaccination campaign. Employing the parameter estimates of the model fitting, the model was used to investigate the effect of alternative timings, coverages and dosages of the OPV campaign on the outcome of the outbreak.ResultsThe mean estimate for the mean reproductive number was 1.77 (95 % credible interval, 1.46–2.30). With seasonal variation, the reproductive number maximum range was between zero and six. The mean estimate for the mean infectious periods was 16.8 (8.6–24.9) days. The modeling indicates the OPV campaign was effective in curtailing the outbreak. The mean estimate for the attack rate in Bedouin children under 10 at the end of 2014 was 42 % (22–65 %), whereas without the campaign the mean projected attack rate was 57 % (35–74 %). The campaign also likely shortened the duration of the outbreak by a mean estimate of 309 (2–846) days. A faster initiation of the OPV campaign could have reduced the incidence of WPV even if a lower coverage was reached, at the risk of prolonging the outbreak.ConclusionsOPV campaigns are essential for interrupting WPV transmission, even in a developed country setting with a high coverage of IPV. In this setting, establishing ES of WPV circulation is particularly crucial for early detection and containment of an outbreak.

【 授权许可】

CC BY   
© The Author(s). 2016

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