title: Does working in hospital increases seroprevalence and carrier state against Bordetella pertussis?
abstract: BACKGROUND
  Health care environments have been the setting for a number of pertussis outbreaks. Immunity after vaccination wanes overtime leading to a growing population of susceptible adolescents and adults. A number of pertussis outbreaks have occurred in hospitals resulting in transmission to health care workers (HCWs), and other patients. The aim of this study was to assess immunity status of a group of basic medical students and interns who worked in hospitals for about 4 years.
  
  
  METHODS
  In a cross-sectional study, we measured the serum antibody titer of cases by enzyme-linked immunosorbent assay test. All 70 subjects have received pertussis vaccine in the routine childhood vaccination schedule. All cases were healthy and had no symptoms of any respiratory diseases. We also obtained a pharyngeal culture on Bordet-Gengou Agar for isolating Bordetella pertussis.
  
  
  RESULTS
  The results of B. pertussis pharyngeal culture was positive for 5 (7.1%) cases and negative for 65 (92.9%). The IgM, IgA, and IgG serum antibody was positive in 1.4%, 7.1%, and 11.4% of cases, respectively. The mean age of cases had no significant effect on serum antibody titers (P = 0.23).
  
  
  CONCLUSIONS
  This study showed that majority of cases do not have protective serum antibody against B. pertussis. Working in hospitals does not affect seroprevalence and carrier state of B. pertussis. Immunization schedules that include no booster doses are at increased risk of pertussis. Due to the importance of the transmission in health care settings, vaccination of HCWs is a priority.
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Alireza Emami
authors.initials: AE
authors.lastname: Naeini
authors.affiliation: Department of Infectious Diseases and Tropical Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Zaman
authors.affiliation: Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Farzin
authors.initials: F
authors.lastname: Khorvash
authors.affiliation: Department of Infectious Diseases, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sahar Emami
authors.initials: SE
authors.lastname: Naeini
authors.affiliation: Department of Infectious Diseases, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hesam-Al-Din
authors.initials: HA
authors.lastname: Khodadadi
authors.affiliation: Department of Pathology, Al Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Mokhtari
authors.affiliation: Department of Epidemiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali Mehrabi
authors.initials: AM
authors.lastname: Koushki
keywords: Bordetella pertussis; health care workers; immunity; pertussis vaccine