Incidence of pertussis in persons < or =15 years of age in Valencia, Spain: seroprevalence of antibodies to pertussis toxin (PT) in children, adolescents and adults

J Infect. 2004 Oct;49(3):242-7. doi: 10.1016/j.jinf.2004.03.003.


Purpose: To determine the incidence of pertussis in persons < or =15 years in age in Valencia, Spain. To assess the prevalence of IgG antibodies to pertussis toxin (PT) in children, adolescents and adults.

Methods: Prospective study conducted at paediatric primary care centres. All persons < or =15 years in age presented with persistent cough were enrolled. Parents completed a brief questionnaire and immunization history was obtained from paediatrician records. A blood sample was obtained, for determination of IgG antibodies to Bordetella pertussis toxin (PT) by an ELISA method. A study confirmed-case was the presence of two conditions: (1) cough illness of > or =14 days duration; and (2) ELISA absorbance value of IgG to PT > or =2. Two subjects per clinical-case (same centre and range of age) and parents were asked to participate in the prevalence study.

Results: Sixty-one children < or =15 years in age presented with symptoms leading to a clinical diagnosis of pertussis were detected. Serological evidence of recent pertussis was found in five of these patients (incidence of 46.0/100,000 persons < or =15 years in age). Prevalence of antibodies to B. pertussis (> or =0.3) in children < or =15 years in age and adults was 39 and 33%, respectively. Only a minority of children, adolescents and adults had absorbance values indicative of immunity (> or =1).

Conclusions: These incidence and seroprevalence results show that despite high immunization rates in infancy, B. pertussis is circulating in Spain.

MeSH terms

  • Adolescent
  • Age Distribution
  • Antibodies, Bacterial / blood*
  • Bordetella pertussis / immunology*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Male
  • Pertussis Toxin / immunology*
  • Seroepidemiologic Studies
  • Spain / epidemiology
  • Whooping Cough / epidemiology*
  • Whooping Cough / immunology


  • Antibodies, Bacterial
  • Pertussis Toxin