title: [Source of infection in young infants hospitalized with Bordetella pertussis].
abstract: BACKGROUND
  Despite pertussis vaccination, very young infants have the highest rates of morbidity and mortality caused by the microorganism.
  
  
  OBJECTIVE
  To determine the source of Pertussis infection in infants aged six months or less in Chile.
  
  
  METHODS
  Twenty six household contacts of 10 young infants hospitalized with confirmed Pertussis were studied for the presence of Bordetella Pertussis by polymerase chain reaction (PCR). Clinical and demographic data were analyzed.
  
  
  RESULTS
  Respiratory symptoms were present in 20 (77%) contacts, being cough the most common. Pertussis cases were identified in every household and in 18 (72%) of the household members. four members with B.pertussis were asymptomatic. Source of infection was identified in 80% (8/10) of the infant cases with ages ranging from 6 to 62 years. Half of primary cases had positive PCR and their cough duration was significantly shorter compared to primary cases with negative PCR.
  
  
  CONCLUSIONS
  B. pertussis transmission to young infants occurred mainly within the household where adults are generally the source of the infection. Risk factors for infant infection are the same as in developed countries. Therefore, the same strategies, such as routine vaccination in adolescents and adults or cocoon strategy, will help to prevent this disease in infants.
authors: División de Pediatría, Facultad de Medicina, Pontificia Universidad Católica de ChileTemuco, Chile. cperret@med.puc.cl
authors: Cecilia
authors: C
authors: Perret
authors: Tamara
authors: T
authors: Viviani
authors: Anamaría
authors: A
authors: Peña
authors: Katia
authors: K
authors: Abarca
authors: Marcela
authors: M
authors: Ferrés
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001886:Bordetella pertussis / Q000235:genetics / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D002677:Chile; D016358:Contact Tracing; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D014611:Vaccination; D014917:Whooping Cough / Q000175:diagnosis / Q000635:transmission*; D055815:Young Adult