title: Survey of poliovirus antibodies during the final stage of polio eradication in Egypt.
abstract: BACKGROUND
  Egypt provides ideal conditions for poliovirus (PV) transmission (high population density, high contact rates and low sanitation and hygiene in some areas). Despite excellent program performance, wild poliovirus type 1 (PV1) continue to circulate in 2004. To investigate potential causes for the persistence, we conducted a serological study.
  
  
  METHODS
  Seroprevalence surveys were conducted in "polio-endemic" regions (Greater Cairo and Upper Egypt) and in one control region (Lower Egypt) in December 2004. Sera collected from infants aged 6-11 months were tested for antibodies to poliovirus by neutralization assay.
  
  
  RESULTS
  A total of 973 subjects were tested. Seroprevalence to PV type 1 (PV1), PV type 2 (PV2) and PV type 3 (PV3) was 99, 99 and 91%, respectively. Significant variation in PV3 seroprevalence was found (range: 76-100%). Region, density, maternal education, socioeconomic status (SES), stunting and diarrhea were significant risk factors for lower seroprevalence in the univariate analysis.
  
  
  CONCLUSIONS
  Our study suggested that uniformly high immunity levels (>96%) were required to interrupt PV1 transmission in the last remaining reservoirs (last PV1 was isolated in mid-January 2005 in Egypt). It further suggests substantial regional differences in OPV immunogenicity, with rural areas and low SES achieving the lowest seroprevalence to PV3.
authors.affiliation: Ministry of Health and Population (MOHP), Cairo, Egypt.
authors.forename: Nasr
authors.initials: N
authors.lastname: El-Sayed
authors.forename: Samir
authors.initials: S
authors.lastname: Al-Jorf
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hennessey
authors.forename: Maha
authors.initials: M
authors.lastname: Salama
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Watkins
authors.forename: Jalaa A
authors.initials: JA
authors.lastname: Abdelwahab
authors.forename: Mark A
authors.initials: MA
authors.lastname: Pallansch
authors.forename: Howard
authors.initials: H
authors.lastname: Gary
authors.forename: Mohamed Helmy
authors.initials: MH
authors.lastname: Wahdan
authors.forename: Roland W
authors.initials: RW
authors.lastname: Sutter
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D001800:Blood Specimen Collection; D003627:Data Interpretation, Statistical; D004197:Disease Reservoirs; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology / Q000517:prevention & control*; D017955:Poliovirus / Q000276:immunology*; D012307:Risk Factors; D018401:Sample Size; D016036:Seroepidemiologic Studies; D009626:Terminology as Topic
chemical_list: D000914:Antibodies, Viral