Human coronavirus NL63 in children with acute upper respiratory tract infection by reverse transcription polymerase chain reaction (RT-PCR)

Background and aim: Human coronavirus NL63 (HCoV-NL63) is a recently discovered human corona virus that causes respiratory illness in children. In this study, we looked for HCoV-NL63 in children with acute upper respiratory tract infection by reverse transcription polymerase chain reaction (RT-PCR) and determined coinfections between HCoV-NL63 and other respiratory viruses. Subjects and methods: Nasal secretions collected from 160 children with acute upper respiratory tract infection and 80 controls were subjected to reverse transcription-PCR (RT-PCR) for detection of HCoV-NL63 virus and direct immunofluorescence (DIF) for detection of seven respiratory viruses (RSV, influenza A and B viruses, parainfluenza virus types 1 to 3, and adenovirus). Results: We detected HCoV-NL63 RT-PCR in 24 out of 160 (15%) nasal secretion specimens collected from children with acute upper respiratory tract infection. All children with HCoV-NL63 infection were aged from 12- 32 months. Direct immunofluorescence assay detected RSV, influenza A, influenza B, and adenovirus in 42(26.3%), 23 (14.4%), 15 (9.4%) and 4(2.5%) respectively in the nasal secretion specimens of the patients. RSV was detected positive in 10 (43.4%) children with HCoV-NL63 infection, influenza A was detected positive in 4 (17.4%) patients with HCoV-NL63 infection, 4 (17.4%) patients with RSV infection and 3 (13%) patients with influenza B infection. While RSV was detected positive in 2 (8.7%) adenovirus infection. Conclusion: HCoV-NL63 is frequently detected human pathogen, often associated with other respiratory viruses and acute respiratory tract infections in children. Rapid DIF screening reagent for detection of multiple respiratory viruses within 1 to 2 hours is of great benefit in terms of patient management and infection control.