title: Prospective surveillance study of acute respiratory infections, influenza-like illness and seasonal influenza vaccine in a cohort of juvenile idiopathic arthritis patients.
abstract: BACKGROUND
  Acute respiratory infections (ARI) are frequent in children and complications can occur in patients with chronic diseases. We evaluated the frequency and impact of ARI and influenza-like illness (ILI) episodes on disease activity, and the immunogenicity and safety of influenza vaccine in a cohort of juvenile idiopathic arthritis (JIA) patients.
  
  
  METHODS
  SURVEILLANCE OF RESPIRATORY VIRUSES WAS CONDUCTED IN JIA PATIENTS DURING ARI SEASON (MARCH TO AUGUST) IN TWO CONSECUTIVE YEARS: 2007 (61 patients) and 2008 (63 patients). Patients with ARI or ILI had respiratory samples collected for virus detection by real time PCR. In 2008, 44 patients were immunized with influenza vaccine. JIA activity index (ACRPed30) was assessed during both surveillance periods. Influenza hemagglutination inhibition antibody titers were measured before and 30-40 days after vaccination.
  
  
  RESULTS
  During the study period 105 ARI episodes were reported and 26.6% of them were ILI. Of 33 samples collected, 60% were positive for at least one virus. Influenza and rhinovirus were the most frequently detected, in 30% of the samples. Of the 50 JIA flares observed, 20% were temporally associated to ARI. Influenza seroprotection rates were higher than 70% (91-100%) for all strains, and seroconversion rates exceeded 40% (74-93%). In general, response to influenza vaccine was not influenced by therapy or disease activity, but patients using anti-TNF alpha drugs presented lower seroconversion to H1N1 strain. No significant differences were found in ACRPed30 after vaccination and no patient reported ILI for 6 months after vaccination.
  
  
  CONCLUSIONS
  ARI episodes are relatively frequent in JIA patients and may have a role triggering JIA flares. Trivalent split influenza vaccine seems to be immunogenic and safe in JIA patients.
authors.affiliation: Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes 3900, S/N. Campus Universitário - Vila Monte Alegre, Ribeirão Preto 14049-900, Brazil.
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Carvalho
authors.affiliation: Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes 3900, S/N. Campus Universitário - Vila Monte Alegre, Ribeirão Preto 14049-900, Brazil.
authors.forename: Flávia E
authors.initials: FE
authors.lastname: de Paula
authors.affiliation: Evandro Chagas Institute, WHO National Influenza Center, Rodovia BR-316 Km 7, Ananindeua 67030-000, Brazil.
authors.forename: Rodrigo V D
authors.initials: RV
authors.lastname: Silvestre
authors.affiliation: Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes 3900, S/N. Campus Universitário - Vila Monte Alegre, Ribeirão Preto 14049-900, Brazil.
authors.forename: Luciana R
authors.initials: LR
authors.lastname: Roberti
authors.affiliation: Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes 3900, S/N. Campus Universitário - Vila Monte Alegre, Ribeirão Preto 14049-900, Brazil.
authors.forename: Eurico
authors.initials: E
authors.lastname: Arruda
authors.affiliation: Evandro Chagas Institute, WHO National Influenza Center, Rodovia BR-316 Km 7, Ananindeua 67030-000, Brazil.
authors.forename: Wyller A
authors.initials: WA
authors.lastname: Mello
authors.affiliation: Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes 3900, S/N. Campus Universitário - Vila Monte Alegre, Ribeirão Preto 14049-900, Brazil.
authors.forename: Virginia P L
authors.initials: VP
authors.lastname: Ferriani
keywords: Acute respiratory infections; Influenza vaccine; Influenza-like illness; Juvenile idiopathic arthritis; Respiratory viruses