Respiratory viruses in patients and employees in an intensive care unit

Purpose To evaluate the frequency of respiratory viruses in a nonselected population of intensive care unit patients and employees and to investigate the clinical as well as the epidemiological association with virological findings. Methods Between 12 January and 5 March 2009, nasopharyngeal swabs were collected from 55 intensive care unit (ICU) patients and 41 medical personnel at 16 different time-points and tested for 11 respiratory viruses by single real-time PCR using TaqMan or MGB probes. Results Among the 55 ICU patients tested, there were 30 virus-positive respiratory specimens (30/173, 17.3%) and 23 patients who tested positive at least once for respiratory viruses (23/55, 41.8%). Only the time from admission to the ICU was associated with the probability of testing positive, with the probability of testing positive decreasing with increasing length of stay ( P < 0.001). Of the 418 respiratory specimens collected from the healthcare personnel, 27 (6.5%) tested positive. Seventeen employees tested positive at least once for respiratory viruses (17/41, 41.5%). Among the employees, calendar time ( P = 0.03) and having sick contacts at home ( P = 0.006) were significantly associated with swab positivity. Among the study population, patients had a significantly higher probability of having a positive swab result than employees. The distribution of viruses differed between the two groups. Conclusions Our results suggest that when hygiene precautions are adopted, the possibility of transmitting selected respiratory viruses between patients and personnel is limited. They also point to a greater importance of the community over the hospital environment for acquisition of viral respiratory infections by ICU patients and employees.