Comparison of direct fluorescent test with real-time PCR to detect acute lower respiratory tract virus infections in children from May to July 2014, in a tertiary care hospital in Sri Lanka

Abstract

In this study, direct fluorescent test (DFT) and real-time PCR (rtPCR) were compared for the detection of acute lower respiratory tract virus infections caused by respiratory syncytial virus (RSV) A and B, influenza (Flu) A and B, parainfluenza virus (PIV) 1, 2, 3 and 4 and adenovirus (AdV) in children admitted to the Lady Ridgeway Hospital, Colombo. Nasopharyngeal aspirates/swabs were obtained from May to July, 2014. Cell pellets were subjected to DFT. Extracted viral RNA were subjected to four different real-time multiplex PCR assays to detect the above respiratory viruses. Of seventy-five specimens, at least one virus was detected in 8 (10.7%) by DFT and in 69 (92%) by rtPCR. The most common viruses detected were RSV-A (5.4%), adenovirus (2.6%) PIV type1/3 (1.3%) by DFT and AdV (70.7%), RSV-A (42.6%), PIV1/3(14.6%), Flu A (8%), and PIV-2/4(1.3%) by rtPCR. Real-time PCR yielded more significant results than DFT in detection of respiratory viruses.

Keywords

• respiratory viruses, direct fluorescent test, real-time pcr