Influenza and respiratory syncytial viruses: efficacy of different diagnostic assays

ABSTRACT

To determine the efficacy of cell culture, immunoflourescence Assay [IFA] and real time polymerase chain reaction [rRT-PCR] in relation to diagnosis of influenza and Respiratory Syncytial Virus [RSV]. Total 2781 specimens of throat swabs and nasopharyngeal aspirates were obtained from patients suspected of respiratory viruses' infections from January 2009 to December 2011 at Universiti Kebangsaan Malaysia Medical Centre [UKMMC].The specimens were processed by cell culture and immunoflurescence assay [IFA] and [rRT-PCR]. Thirty three [1.19%] specimens were positive for influenza virus A and 42 [1.51%] were positive for RSV by cell culture and IFA. On the other hand, rRT-PCR was able to identify 189 of 505 [37.43%] specimens in which 65 were influenza A virus and 124 were RSV. Sensitivity of rRT-PCR was 100% for both influenza A virus and RSV and specificity was 88% and 77% for influenza A virus and RSV, respectively. rRT-PCR diagnosed respiratory viruses in shorter time with a high level of sensitivity in comparison to conventional assays - cell culture and IFA. These advantages help in managing patients by saving cost and hospitalization stay