Clinical relevance of multiple respiratory virus detection in adult patients with acute respiratory illness.

Because increasing numbers of nasopharyngeal swab specimens from adult patients with acute respiratory illness (ARI) are being tested by respiratory virus (RV) multiplex reverse transcriptase PCR (RVM-RT-PCR), multiple RV detection (MRVD) is being encountered more frequently. However, the clinical relevance of MRVD in adult patients has rarely been evaluated. The clinical characteristics of hospitalized adult patients with ARI and MRVD by RVM-RT-PCR tests were compared to those of patients with single RV detection (SRVD) during a single year at a tertiary care center. MRVD was observed in 26 of the 190 adult patients (13.7%). The patients with MRVD had a higher incidence of chronic lung disease than the patients with SRVD (34.6% versus 15.9%, crude odds ratio [OR]=2.81, 95% confidence interval [CI]=1.13 to 6.98, P=0.03). Although the former were more likely than the latter to receive mechanical ventilation (19.2% versus 6.7%, crude OR=3.31, 95% CI=1.05 to 10.47, P=0.049), the length of hospital stay (median, 7 versus 6.5 days; P=0.66), and the in-hospital mortality rate (7.7% versus 4.3%, crude OR=1.87, 95% CI=0.37 to 9.53, P=0.35) were not different between the two groups. In multivariate analysis, chronic lung disease was associated with MRVD (adjusted OR=3.08, 95% CI=1.12 to 8.46, P=0.03). In summary, it was not uncommon to encounter adult patients with ARI and MRVD by RVM-RT-PCR tests of nasopharyngeal swab specimens. MRVD was associated with chronic lung disease rather than the severity of the ARI.