Nosocomial H1N1 infection during 2010-2011 pandemic: a retrospective cohort study from a tertiary referral hospital.

This study aimed to estimate the incidence of hospital transmission of influenza A subtype H1N1 [A(H1N1)], to identify high-risk areas for such transmission and to evaluate common characteristics of affected patients. In this single-centre retrospective cohort study, 10 patients met the criteria for hospital-acquired A(H1N1) infection over a three-month period. All affected patients required an escalation of their care and the mortality rate was 20%. Clinicians should be aware of the risk of nosocomial A(H1N1) infection that exists despite routine infection control measures and should consider additional control measures including vaccination of hospital inpatients and healthcare staff.