Emerging Infectious Diseases (Oct 2010)

Risk Factors for Pandemic (H1N1) 2009 Virus Seroconversion among Hospital Staff, Singapore

  • Mark I.C. Chen,
  • Vernon J.M. Lee,
  • Ian Barr,
  • Cui Lin,
  • Rachelle Goh,
  • Caroline Lee,
  • Baldev Singh,
  • Jessie Tan,
  • Wei-Yen Lim,
  • Alex R. Cook,
  • Brenda Ang,
  • Angela Chow,
  • Boon Huan Tan,
  • Jimmy Loh,
  • Robert Shaw,
  • Kee Seng Chia,
  • Raymond T.P. Lin,
  • Yee Sin Leo

DOI
https://doi.org/10.3201/eid1610.100516
Journal volume & issue
Vol. 16, no. 10
pp. 1554 – 1561

Abstract

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We describe incidence and risk factors for pandemic (H1N1) 2009 virus infection in healthcare personnel during the June–September 2009 epidemic in Singapore. Personnel contributed 3 serologic samples during June–October 2009, with seroconversion defined as a >4-fold increase in hemagglutination inhibition titers to pandemic (H1N1) 2009. Of 531 participants, 35 showed evidence of seroconversion. Seroconversion rates were highest in nurses (28/290) and lowest in allied health staff (2/116). Significant risk factors on multivariate analysis were being a nurse (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 1.0–19.6) and working in pandemic (H1N1) 2009 isolation wards (aOR 4.5, 95% CI 1.3–15.6). Contact with pandemic (H1N1) 2009–infected colleagues (aOR 2.5, 95% CI 0.9–6.6) and larger household size (aOR 1.2, 95% CI 1.0–1.4) were of borderline significance. Our study suggests that seroconversion was associated with occupational and nonoccupational risk factors.

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