Predictive value of testing nasopharyngeal samples for respiratory viruses in the setting of lower respiratory tract disease.

To determine the predictive value of nasopharyngeal (NP) sample testing for respiratory viruses (RVs) in suspected lower respiratory tract disease, 72 paired NP and bronchoalveolar lavage (BAL) fluid specimen sets, mostly from transplant recipients or patients with hematologic malignancies, were analyzed. Overall, 31.3% of the specimens tested positive for an RV. In 19 sets (26.4%), the NP and BAL fluid specimens were both positive for an RV; in 3 sets (4.2%), the NP specimens were positive but the BAL fluid specimens were negative; and in 3 other sets, the NP specimens were negative but the BAL fluid specimens were positive. The positive and negative predictive values of the NP specimens were 86.4% and 94%, respectively.