Interpretation of Positive Result for Influenza A and Negative Result for Novel Influenza A/H1N1 in Reverse Transcriptase PCR for Novel Influenza A/H1N1.
- Author:
Young Kyung LEE
1
;
Han Sung KIM
;
Hyun Soo KIM
;
Jae Seok KIM
;
Wonkeun SONG
;
Hee Jung KANG
;
Kyu Man LEE
Author Information
1. Department of Laboratory Medicine, Hallym University College of Medicine, Chuncheon, Korea. kimhan@hallym.ac.kr
- Publication Type:Original Article
- Keywords:
Novel influenza A/H1N1;
Seasonal influenza A;
Real-time RT-PCR
- MeSH:
Diagnosis, Differential;
Influenza, Human;
Nucleotides;
Reverse Transcriptase Polymerase Chain Reaction;
RNA-Directed DNA Polymerase;
Seasons
- From:Journal of Laboratory Medicine and Quality Assurance
2009;31(2):287-291
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Real-time reverse transcriptase PCR (rRT-PCR) is widely used to detect novel influenza A/H1N1. We had observed several cases with positive result for influenza A and negative result for novel influenza A/H1N1 during a novel influenza A/H1N1 outbreak. The causes of those results were investigated in this study. METHODS: A total of 913 cases tested with rRT-PCR for novel influenza A/H1N1 (Real-time Ready Influenza A/H1N1 Detection Set, Roche Diagnostics, Germany) during 25 August 2009 to 8 September 2009 was enrolled in this study. Cases showing positive result for influenza A (M gene) and negative result for novel influenza A/H1N1 (H1 gene) were tested with multiplex RT-PCR for seasonal influenza and novel influenza A/H1N1 (Seeplex FluA ACE Subtyping kit, Seegene, Korea), and the amplicons were directly sequenced. RESULTS: One hundred and eleven cases (12.2%) were positive for novel influenza A/H1N1. Twenty-seven cases (3.0%) were positive for influenza A, but negative for novel influenza A/H1N1. Subtypes of influenza A were determined in 25 cases by multiplex RT-PCR and nucleotides sequencing. One novel influenza A/H1N1, six seasonal influenza A/H1N1, three seasonal influenza A/H3N2, and 15 influenza A/H9N2 were detected. CONCLUSIONS: Subtypes of influenza A were determined in most cases with positive result for influenza A and negative result for novel influenza A/H1N1. Several cases with seasonal influenza A were detected. Even if a nonepidemic period of seasonal influenza, tests for seasonal influenza A can help in the differential diagnosis of influenza.
