title: Poliovirus seroprevalence before and after interruption of poliovirus transmission in Kano State, Nigeria.
abstract: In September 2015, Nigeria was removed from the list of polio-endemic countries after more than 12months had passed since the detection of last wild poliovirus case in the country on 24 July 2014. We are presenting here a report of two polio seroprevalence surveys conducted in September 2013 and October 2014, respectively, in the Kano state of northern Nigeria.
  
  
  
  Health facility based seroprevalence surveys were undertaken at Murtala Mohammad Specialist Hospital, Kano. Parents or guardians of children aged 6-9months, 36-47months, 5-9years and 10-14years in 2013 and 6-9months and 19-22months (corresponding to 6-9months range at the time of 2013 survey) in 2014 presenting to the outpatient department, were approached for participation, screened for eligibility and asked to provide informed consent. A questionnaire was administered and a blood sample collected for polio neutralization assay.
  
  
  
  Among subjects aged 6-9months in the 2013 survey, seroprevalence was 58% (95% confidence interval [CI] 51-66%) to poliovirus type 1, 42% (95% CI 34-50%) to poliovirus type 2, and 52% (95% CI 44-60%) to poliovirus type 3. Among children 36-47months and older, seroprevalence was 85% or higher for all three serotypes. In 2014, seroprevalence in 6-9month infants was 72% (95% CI 65-79%) for type 1, 59% (95% CI 52-66%) for type 2, and 65% (95% CI 57-72%) for type 3 and in 19-22months, 80% (95% CI 74-85%), 57% (49-63%) and 78% (71-83%) respectively. Seroprevalence was positively associated with history of increasing oral poliovirus vaccine doses.
  
  
  
  There was significant improvement in seroprevalence in 2014 over the 2013 levels indicating a positive impact of recent programmatic interventions. However the continued low seroprevalence in 6-9month age is a concern and calls for improved immunization efforts to sustain the polio-free Nigeria.
authors: Department of Community Medicine, Aminu Kano Teaching Hospital & Bayero University Kano, Nigeria.
authors: Zubairu
authors: Z
authors: Iliyasu
authors: World Health Organization, Geneva, Switzerland. Electronic address: vermah@who.int.
authors: Harish
authors: H
authors: Verma
authors: World Health Organization, Abuja, Nigeria.
authors: Kehinde T
authors: KT
authors: Craig
authors: National Primary Health Care Development Agency, Abuja, Nigeria.
authors: Eric
authors: E
authors: Nwaze
authors: National Primary Health Care Development Agency, Abuja, Nigeria.
authors: Amina
authors: A
authors: Ahmad-Shehu
authors: Department of Pediatrics, Murtala Mohammed Specialist Hospital, Kano, Nigeria.
authors: Binta Wudil
authors: BW
authors: Jibir
authors: Department of Pediatrics, Aminu Kano Teaching Hospital & Bayero University, Kano, Nigeria.
authors: Garba Dayyabu
authors: GD
authors: Gwarzo
authors: Department of Community Medicine, Aminu Kano Teaching Hospital & Bayero University Kano, Nigeria.
authors: Auwalu U
authors: AU
authors: Gajida
authors: Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors: William C
authors: WC
authors: Weldon
authors: Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors: M
authors: M
authors: Steven Oberste
authors: World Health Organization, Geneva, Switzerland.
authors: Marina
authors: M
authors: Takane
authors: World Health Organization, Abuja, Nigeria.
authors: Pascal
authors: P
authors: Mkanda
authors: National Primary Health Care Development Agency, Abuja, Nigeria.
authors: Ado J G
authors: AJG
authors: Muhammad
authors: World Health Organization, Geneva, Switzerland.
authors: Roland W
authors: RW
authors: Sutter
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D060740:Disease Eradication; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D011051:Poliomyelitis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission* / Q000821:virology; D017955:Poliovirus / Q000276:immunology / Q000302:isolation & purification; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage*; D016036:Seroepidemiologic Studies; D065288:Serogroup; D011795:Surveys and Questionnaires
chemical_list: D000914:Antibodies, Viral; D011055:Poliovirus Vaccine, Oral
keywords: Kano; Nigeria; Oral poliovirus vaccine; Poliomyelitis; Seroprevalence