Comparison of virus isolation using the Vero E6 cell line with real-time RT-PCR assay for the detection of human metapneumovirus
1 Course of Clinical Nursing, Yamagata University Faculty of Medicine, Iida-nishi, 2-2-2, Yamagata, 990-9585, Japan
2 Department of Microbiology, Yamagata Prefectural Institute of Public Health, Tokamachi 1-6-6, Yamagata, 990-0031, Japan
3 Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama, Tokyo, 208-0011, Japan
4 Virus Research Center, Clinical Research Division, Sendai Medical Center, Miyagino-ku Miyagino 2-8-8, Sendai, 983-8520, Japan
5 Yamanobe Pediatric Clinic, Yamanobe 2908-14, Yamagata, 990-0301, Japan
6 Katsushima Pediatric Clinic, Minamidate 4-4-12, Yamagata, 990-2461, Japan
7 Nagai Children's Clinic, Miyagino-ku Miyagino 1-25-10, Sendai, 983-0045, Japan
8 Department of Infectious Diseases, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata, 990-9585, Japan
9 Department of Virology Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai, 980-8575, Japan
BMC Infectious Diseases 2010, 10:170 doi:10.1186/1471-2334-10-170Published: 14 June 2010
The use of cell culture for the diagnosis of human metapneumovirus (hMPV) infection is uncommon at present and molecular method such as reverse-transcription PCR (RT-PCR) has been widely and most commonly used as the preferred test. We aimed to compare the results of virus isolation using Vero E6 cells with real-time RT-PCR for the detection of hMPV, since such a comparison data is not available.
Between December 2007 and July 2008, we obtained 224 nasopharyngeal swab specimens from patients with acute respiratory infection and tested by the two methods.
Forty-three (19.2%) were found positive by cell culture and 62 (27.7%) by real-time RT-PCR. Cell cultures were positive for 42 of 62 specimens found positive by real-time RT-PCR (67.7% sensitivity) and for 1 of 162 specimens found negative by real-time RT-PCR (99.4% specificity), respectively. The sensitivity of the cell culture was 76.2-87.5% (mean 81.8%) when specimens were collected within 3 days after the onset of symptoms, and the sensitivity decreased to 50% or less thereafter. Among specimens collected within 3 days after symptom onset, all of the real-time RT-PCR positive specimens having a viral load of more than 1.25×105 copies/ml were found positive by cell culture.
Cell culture using Vero E6 cell line has 81.8% sensitivity compared with the real-time RT-PCR method, when specimens are collected within 3 days after the onset of symptoms. Thus, this method is a useful method for epidemiological and virological research even in facilities with minimal laboratory resources.