a1 Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
a2 Vanderbilt University School of Medicine, Nashville, Tennessee
a3 Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
a4 Department of Biostatistics, Vanderbilt University, Nashville, Tennessee
a5 Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee
a6 Departments of Pediatrics and Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
a7 Department of Preventive Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
Background. Healthcare-associated transmission of respiratory viruses is a concerning patient safety issue.
Design. Surveillance for influenza virus among a cohort of healthcare workers (HCWs) was conducted in a tertiary care children's hospital from November 2009 through April 2010 using biweekly nasal swab specimen collection. If a subject reported respiratory symptoms, an additional specimen was collected. Specimens from ill HCWs and a randomly selected sample from asymptomatic subjects were tested for additional respiratory viruses by multiplex polymerase chain reaction (PCR).
Results. A total of 1,404 nasal swab specimens were collected from 170 enrolled subjects. Influenza circulated at very low levels during the surveillance period, and 74.2% of subjects received influenza vaccination. Influenza virus was not detected in any specimen. Multiplex respiratory virus PCR analysis of all 119 specimens from symptomatic subjects and 200 specimens from asymptomatic subjects yielded a total of 42 positive specimens, including 7 (16.7%) in asymptomatic subjects. Viral shedding was associated with report of any symptom (odds ratio [OR], 13.06 [95% confidence interval, 5.45–31.28]; P< .0001) and younger age (OR, 0.96 [95% confidence interval, 0.92–0.99]; P = .023) when controlled for sex and occupation of physician or nurse. After the surveillance period, 46% of subjects reported working while ill with an influenza-like illness during the previous influenza season.
Conclusions. In this cohort, HCWs working while ill was common, as was viral shedding among those with symptoms. Asymptomatic viral shedding was infrequent but did occur. HCWs should refrain from patient care duties while ill, and staffing contingencies should accommodate them.
(Received August 21 2012)
(Accepted November 21 2012)