Comparison of Culture, Direct Immunofluorescence Assay, and Multiplex Reverse Transcriptase PCR for Detection of Respiratory Viruses

ABSTRACT

BACKGROUND: Rapid detection of causative viruses is important for the management of acute respiratory illnesses. To increase the detection rate and decrease the turnaround time (TAT) and cost, we used 24-well plates instead of R-mix shell vials and changes the report time from once on day 3 to twice on days 1 and 5 of culture. The detection rate and TATs of each culture method, direct immunofluorescence assay (DFA), and multiplex reverse transcriptase polymerase chain reaction (mPCR) were compared. METHODS: Among 2,062 nasopharyngeal swabs (NPSs) received from January 2009 to January 2011, 707 NPSs were cultured in R-mix shell vials and 1,355 NPSs were cultured in 24-well plates. We analyzed 538 NPSs simultaneously using DFA, mPCR, and culture and compared the detection rate for 7 viruses (adenovirus, influenza A and B virus; parainfluenza virus 1, 2, and 3; and respiratory syncytial virus [RSV]). RESULTS: The detection rate when using shell vials was 28.4% (201/707) and was 29.4% (399/1,355) on day 1 and 33.3% (452/1,355) on day 5 when using 24-well plates. In addition, of the 53 viruses that were detected on day 5, 34 were adenovirus, 7 were parainfluenza virus, 4 were influenza A virus, 3 were influenza B virus, 4 were RSV, and 1 was a mix of influenza B and parainfluenza virus. The TAT when using shell vials and 24-well plates was 4.8 days and 2.5 days, respectively. The detection rate for the 7 respiratory viruses using culture, DFA, and mPCR was 24.3%, 20.8%, and 38.5%, and the TAT was 3.7 days, 1.0 day, and 1.4 days, respectively. CONCLUSIONS: Using 24-well plates for virus culture is an efficient method for the detection of respiratory viruses.