title: Factors influencing the spread of pertussis in households: a prospective study, Catalonia and Navarre, Spain, 2012 to 2013.
abstract: We aimed to investigate transmission rates of pertussis in household contacts of cases and factors associated with transmission. A prospective epidemiological study was conducted in 2012 and 2013 to determine the incidence of pertussis among household contacts of reported cases in Catalonia and Navarre, Spain. An epidemiological survey was completed for each case and contact, who were followed for 28 days to determine the source of infection (primary case) and detect the occurrence of secondary cases. Odds ratios (ORs) were used to estimate the effectiveness of vaccination and chemoprophylaxis in preventing new cases, using the formula (1 - OR) × 100. For the 688 primary cases, a total of 2,852 contacts were recorded. The household transmission rate was 16.1% (459/2,852) and rose according to the age (> 18 years) and lack of immunisation of the primary cases, and also the age (0-18 years), family relationship (siblings and children), lack of vaccination and chemoprophylaxis of contacts. Pertussis vaccine effectiveness in preventing new cases was 65.0% (95% confidence interval (CI): 11.6 to 86.2) for full vaccination (≥ 4 doses) and 59.7% (95% CI: -6.8 to 84.8) for incomplete vaccination (< 4 doses). The effectiveness of chemoprophylaxis was 62.1% (95% CI: 40.3 to 75.9). To reduce household transmission, contacts should be investigated to detect further cases and to administer chemoprophylaxis. The current vaccination status of cases and contacts can reduce household transmission.
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.|Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Institut de Recerca Biomèdica de Lleida, IRBLleida, Lleida, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Godoy
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Instituto de Salud Pública de Navarra, IdiSNA, Pamplona, Spain.|Universidad Pública de Navarra (UPNA), Navarre, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: García-Cenoz
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Universitat de Barcelona, Barcelona, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Toledo
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: Glòria
authors.initials: G
authors.lastname: Carmona
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Agència de Salut Pública de Barcelona, Barcelona, Spain.
authors.forename: Joan A
authors.initials: JA
authors.lastname: Caylà
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.|Institut de Recerca Biomèdica de Lleida, IRBLleida, Lleida, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Alsedà
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Àlvarez
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Barrabeig
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Camps
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.|Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Plans
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Company
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Instituto de Salud Pública de Navarra, IdiSNA, Pamplona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Castilla
authors.affiliation: Agència de Salut Pública de Catalunya, Barcelona, Spain.
authors.forename: Maria-Rosa
authors.initials: MR
authors.lastname: Sala-Farré
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Hospital de Sant Joan de Dèu, Barcelona, Spain.|Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Muñoz-Almagro
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Agència de Salut Pública de Barcelona, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rius
authors.affiliation: Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain.|Universitat de Barcelona, Barcelona, Spain.
authors.forename: Àngela
authors.initials: À
authors.lastname: Domínguez
authors.affiliation: Members of the group are listed at the end of the article.
mesh_terms: D000293:Adolescent; D000328:Adult; D018890:Chemoprevention; D002648:Child; D002675:Child, Preschool; D005191:Family Characteristics; D005192:Family Health / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010567:Pertussis Vaccine / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology; D014611:Vaccination / Q000706:statistics & numerical data*; D014917:Whooping Cough / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D055815:Young Adult
chemical_list: D010567:Pertussis Vaccine
keywords: Chemoprophylaxis; Household; Pertussis; epidemiology; transmission; vaccine