American Journal of Infection Control
Vol 41 | No. 7 | July 2013 | Pages 575-666
http://www.ajicjournal.org/current

Pandemic 2009 H1N1 influenza among health care workers
Renata D. Lobo, RN, MS; Maura S. Oliveira, MD, MS; Cilmara P. Garcia, MD; Helio Hehl Caiaffa Filho, MS; Anna S. Levin, MD, PhD
published online 02 January 2013. http://www.ajicjournal.org/article/S0196-6553%2812%2901240-0/abstract

Abstract
To evaluate factors associated with pandemic influenza among health care workers (HCWs), a case-case-control study was conducted with 52 confirmed cases, 120 influenza-negative cases, and 102 controls. Comorbidities (odds ratio [OR], 19.05; 95% confidence interval [95% CI]: 4.75–76.41), male sex (OR, 5.11; 95% CI: 1.80–14.46), and being a physician (OR, 8.58; 95% CI: 2.52–29.27) were independent risk factors for pandemic influenza infection among HCWs. Contact with symptomatic coworker or social contact was protective (OR, 0.11; 95% CI: 0.04–0.29). To our knowledge, this is the first study of factors associated with acquiring influenza involving HCW in nonsevere cases.