title: Prevalence of anti-poliovirus type 1, 2 and 3 antibodies in unvaccinated Italian travelers.
abstract: BACKGROUND
  Immunization against poliomyelitis is recommended for international travelers to developing countries. However, the level of antibodies varies even in previously unvaccinated persons, due to wild-type or vaccine-type infections in the eldest travelers.
  
  
  METHODS
  In 1999, we conducted a seroprevalence study in the Lombardy region (northern Italy), using sera collected in 1994 from a population aged 50 to 59 years. The study subjects were consecutive, randomly selected travelers enrolled in an anti-hepatitis A virus antibody study. Neutralizing antibodies were titrated on Vero cells in microtiter plates. Each serum dilution (1:8 to 1:256) was challenged against 100 tissue culture infective doses of the three Sabin strains. Titers> 1:8 were considered to be protective.
  
  
  RESULTS
  We studied 98 travelers, 59 male and 39 female, of mean age 54 years. Seventy-three (74.4%) reported previous travel abroad, but none had been vaccinated against polio. Dietary habits included consumption of seafood in 74.4% and raw vegetables from their own garden in 52.1%. The seroprevalences for neutralizing antibodies against poliovirus type 1, type 2 and type 3 were 86.7%, 89.9%, and 86.7%, respectively. All travelers presented protective antibody titers against at least one of the three viral types. Protective antibody titers were unrelated to travel history or dietary habit.
  
  
  CONCLUSIONS
  A high proportion of the previously unvaccinated adults in our sample presented protective immunity to polioviruses. This observation may have implications for cost-effectiveness analysis of generalized polio vaccination in adult Italian travelers.
authors.affiliation: Institute of Infectious and Tropical Diseases, University of Brescia, Italy.
authors.forename: Liana
authors.initials: L
authors.lastname: Signorini
authors.forename: Maria
authors.initials: M
authors.lastname: Barbi
authors.forename: Alberto
authors.initials: A
authors.lastname: Matteelli
authors.forename: Sandro
authors.initials: S
authors.lastname: Binda
authors.forename: Patrizia
authors.initials: P
authors.lastname: Didò
authors.forename: Simona
authors.initials: S
authors.lastname: Caroppo
authors.forename: Valeria
authors.initials: V
authors.lastname: Primache
authors.forename: Salvatore
authors.initials: S
authors.lastname: Pisani
authors.forename: Crescenzo
authors.initials: C
authors.lastname: Messino
authors.forename: Maria
authors.initials: M
authors.lastname: Brunelli
authors.forename: Paolo
authors.initials: P
authors.lastname: Costa
authors.forename: Enrico
authors.initials: E
authors.lastname: Ronca
authors.forename: Caterina
authors.initials: C
authors.lastname: Fausti
authors.forename: Francesco
authors.initials: F
authors.lastname: Castelli
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011051:Poliomyelitis / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology / Q000517:prevention & control*; D017955:Poliovirus / Q000276:immunology*; D016036:Seroepidemiologic Studies; D014195:Travel; D014611:Vaccination / Q000706:statistics & numerical data
chemical_list: D000914:Antibodies, Viral