BACKGROUND: The quality of clinical specimens is a crucial determinant for virological diagnosis. OBJECTIVES: We compared the viral diagnostic yield for influenza A and respiratory syncytial virus (RSV) from the recently developed nasopharyngeal flocked swabs (NPFS) with nasopharyngeal aspirates (NPA) collected in parallel from 196 hospitalized children with acute respiratory infection during the peak period of influenza A and RSV activity in Hong Kong. Specimens were tested by RT-PCR for influenza A and RSV and viral load determined. They were also tested by direct immunofluorescence (DIF) for influenza A and B, RSV, parainfluenza types 1-3 and adenovirus. RESULTS: Both NPA and NPFS had excellent sensitivity (100%) for detecting influenza A by RT-PCR but NPA was slightly more sensitive than NPFS for detecting RSV by both RT-PCR (100% vs. 92.3%) and DIF (87.2% vs. 84.6%) and for detecting influenza A by DIF (90.2% vs. 82.9%). Viral load for influenza A in NPA and NPFS was not significantly different but that for RSV was higher in NPA. CONCLUSION: NPA remains the optimal specimen for diagnosis of respiratory infections by RT-PCR and DIF. However, collection of NPFS is easier to perform in an out-patient setting, was more acceptable to parents and less likely to generate aerosols than NPA engendering potentially less infection control hazard.
BACKGROUND: The quality of clinical specimens is a crucial determinant for virological diagnosis. OBJECTIVES: We compared the viral diagnostic yield for influenza A and respiratory syncytial virus (RSV) from the recently developed nasopharyngeal flocked swabs (NPFS) with nasopharyngeal aspirates (NPA) collected in parallel from 196 hospitalized children with acute respiratory infection during the peak period of influenza A and RSV activity in Hong Kong. Specimens were tested by RT-PCR for influenza A and RSV and viral load determined. They were also tested by direct immunofluorescence (DIF) for influenza A and B, RSV, parainfluenza types 1-3 and adenovirus. RESULTS: Both NPA and NPFS had excellent sensitivity (100%) for detecting influenza A by RT-PCR but NPA was slightly more sensitive than NPFS for detecting RSV by both RT-PCR (100% vs. 92.3%) and DIF (87.2% vs. 84.6%) and for detecting influenza A by DIF (90.2% vs. 82.9%). Viral load for influenza A in NPA and NPFS was not significantly different but that for RSV was higher in NPA. CONCLUSION: NPA remains the optimal specimen for diagnosis of respiratory infections by RT-PCR and DIF. However, collection of NPFS is easier to perform in an out-patient setting, was more acceptable to parents and less likely to generate aerosols than NPA engendering potentially less infection control hazard.
Authors: Kwok Hung Chan; Wing Cheong Yam; Chiu Mei Pang; Kit Man Chan; Siu Yan Lam; Kam Fai Lo; Leo L M Poon; J S Malik Peiris Journal: J Clin Microbiol Date: 2008-05-07 Impact factor: 5.948
Authors: Angela P Campbell; Jane Kuypers; Janet A Englund; Katherine A Guthrie; Lawrence Corey; Michael Boeckh Journal: J Clin Microbiol Date: 2012-11-07 Impact factor: 5.948
Authors: Dennis K M Ip; Lincoln L H Lau; Kwok-Hung Chan; Vicky J Fang; Gabriel M Leung; Malik J S Peiris; Benjamin J Cowling Journal: Clin Infect Dis Date: 2015-10-30 Impact factor: 9.079
Authors: Peter P Cheung; Y H Connie Leung; Chun-Kin Chow; Chi-Fung Ng; Chun-Lok Tsang; Yu-On Wu; Siu-Kit Ma; Sin-Fun Sia; Yi Guan; J S M Peiris Journal: J Clin Virol Date: 2009-07-14 Impact factor: 3.168
Authors: Gallen B Triana-Baltzer; Larisa V Gubareva; John M Nicholls; Melissa B Pearce; Vasiliy P Mishin; Jessica A Belser; Li-Mei Chen; Renee W Y Chan; Michael C W Chan; Maria Hedlund; Jeffrey L Larson; Ronald B Moss; Jacqueline M Katz; Terrence M Tumpey; Fang Fang Journal: PLoS One Date: 2009-11-06 Impact factor: 3.240