title: Seroprevalence of antibodies to pandemic (H1N1) 2009 influenza virus among health care workers in two general hospitals after first outbreak in Kobe, Japan.
abstract: OBJECTIVE
  To assess the prevalence including asymptomatic infection, infection risk of exposure to patients, and effectiveness of personal protective equipment (PPE) among health care workers (HCWs) during the first pandemic (H1N1) 2009 (pH1N1) outbreak in Kobe, Japan in May 2009.
  
  
  METHODS
  A cross-sectional seroepidemiological study was conducted on 268 HCWs in the two hospitals in Kobe to which all pH1N1 inpatients were directed. Participating HCWs completed a self-administrated questionnaire and provided a single serum sample which was analyzed using a hemagglutination-inhibition (HI) antibody test.
  
  
  RESULTS
  Of 268 subjects, 14 (5.2%) were found to have positive antibodies to the pH1N1 by HI assay; only 1 reported a febrile episode. Among the 14 seropositive cases, 8 received chemoprophylaxis. 162 HCWs (60.4%) had been exposed to patients. The seropositive rate (SPR) for pH1N1 of the exposed group was higher than that of the unexposed group, however not statistically significant (6.8% vs. 3.1%, p = 0.197). There were no statistically significant differences in SPR for any PPE.
  
  
  CONCLUSIONS
  The SPR for pH1N1 in the exposed group was higher than that of the unexposed group in HCWs; however, most of these individuals were asymptomatic. There was no statistically significant association between PPE implementation and pH1N1 seropositivity.
authors: Field Epidemiology Training Program, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjyuku-ku, Tokyo 162-8640, Japan. t-t@nih.go.jp
authors: Takao
authors: T
authors: Toyokawa
authors: Tomimasa
authors: T
authors: Sunagawa
authors: Yuichiro
authors: Y
authors: Yahata
authors: Takaaki
authors: T
authors: Ohyama
authors: Tomoko
authors: T
authors: Kodama
authors: Hiroshi
authors: H
authors: Satoh
authors: Kumi
authors: K
authors: Ueno-Yamamoto
authors: Satoru
authors: S
authors: Arai
authors: Kazuko
authors: K
authors: Araki
authors: Fumito
authors: F
authors: Odaira
authors: Yuuki
authors: Y
authors: Tsuchihashi
authors: Hideaki
authors: H
authors: Takahashi
authors: Keiko
authors: K
authors: Tanaka-Taya
authors: Nobuhiko
authors: N
authors: Okabe
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D058070:Asymptomatic Diseases / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006282:Health Personnel; D006385:Hemagglutination Inhibition Tests; D006769:Hospitals, General; D006801:Humans; D017053:Infection Control / Q000379:methods; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D011481:Protective Clothing / Q000706:statistics & numerical data; D016036:Seroepidemiologic Studies; D011795:Surveys and Questionnaires
chemical_list: D000914:Antibodies, Viral