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

摘要

Purpose. To determine the incidence of pertussis in persons <==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 <==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 >/=14 days duration; and (2) ELISA absorbance value of IgG to PT >/=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 <==15 years in age presented with symptoms leading to a clinical diagnosis of pertussis were detected. Serological evidence of recentpertussis was found in five of these patients (incidence of 46.0/100?000 persons <==15 years in age). Prevalence of antiobodies to B. pertussis (>/=0.3) in children <==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 (>/=1). Conclusions. These incidence and seroprevalence results show that despite high immunization rates in infancy, B. pertussis is circulating in Spain.