title: Continued Endemic Wild Poliovirus Transmission in Security-Compromised Areas - Nigeria, 2016.
abstract: On August 10, 2016, 2 years after the most recent wild poliovirus (WPV) case was reported in Nigeria (in July 2014) (1), two WPV cases were reported in the northeastern state of Borno, which has been severely affected by insurgency-related insecurity since 2013. On September 9 and 26, 2016, two additional WPV cases were reported in Borno in children whose families migrated from security-compromised, inaccessible areas of the state. All four cases were WPV serotype 1 (WPV1), with genetic differences indicating prolonged undetected transmission. A large-scale emergency response plan was developed and implemented. The plan initially called for vaccination of 815,791 children during August 15-18 in five local government areas (LGAs) in the immediate vicinity of the first two WPV cases. Subsequently, the plan was expanded to regionally synchronized supplementary immunization activities (SIAs), conducted during August 27-December 6 in five Lake Chad basin countries at increased risk for national and regional WPV1 transmission (Cameroon, Central African Republic, Chad, Niger, and Nigeria). In addition, retrospective searches for missed cases of acute flaccid paralysis (AFP), enhanced environmental surveillance for polioviruses, and polio surveillance system reviews were conducted. Prolonged undetected WPV1 transmission in Borno State is a consequence of low population immunity and severe surveillance limitations associated with insurgency-related insecurity and highlights the risk for local and international WPV spread (2). Increasing polio vaccination coverage and implementing high-quality polio surveillance, especially among populations in newly secured and difficult-to-access areas in Borno and other Lake Chad basin areas are urgently needed.
authors.forename: Chimeremma
authors.initials: C
authors.lastname: Nnadi
authors.forename: Eunice
authors.initials: E
authors.lastname: Damisa
authors.forename: Lisa
authors.initials: L
authors.lastname: Esapa
authors.forename: Fiona
authors.initials: F
authors.lastname: Braka
authors.forename: Ndadilnasiya
authors.initials: N
authors.lastname: Waziri
authors.forename: Anisur
authors.initials: A
authors.lastname: Siddique
authors.forename: Jaume
authors.initials: J
authors.lastname: Jorba
authors.forename: Gatei Wa
authors.initials: GW
authors.lastname: Nganda
authors.forename: Chima
authors.initials: C
authors.lastname: Ohuabunwo
authors.forename: Omotayo
authors.initials: O
authors.lastname: Bolu
authors.forename: Eric
authors.initials: E
authors.lastname: Wiesen
authors.forename: Usman
authors.initials: U
authors.lastname: Adamu
mesh_terms: D000068337:Armed Conflicts; D002648:Child; D019353:Endemic Diseases; D006801:Humans; D009549:Nigeria / Q000453:epidemiology; D011051:Poliomyelitis / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D017955:Poliovirus / Q000235:genetics / Q000302:isolation & purification; D023321:Poliovirus Vaccines / Q000008:administration & dosage; D011159:Population Surveillance; D065288:Serogroup; D014611:Vaccination / Q000706:statistics & numerical data
chemical_list: D023321:Poliovirus Vaccines