Rapid Diagnostic Tests for Identifying Avian Influenza A(H7N9) Virus in Clinical Samples

Yu Chen1, Dayan Wang1, Shufa Zheng, Yuelong Shu, Wenxiang Chen, Dawei Cui, Jinming Li, Hongjie Yu, Yu Wang, Lanjuan Li2, and Hong Shang2

Author affiliations: Zhejiang University, Hangzhou, China (Y. Chen, S. Zheng, D. Cui, L. Li); Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou (Y. Chen, S. Zheng, D. Cui, L. Li);National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China (D. Wang, Y. Shu); Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou (D. Wang, Y. Shu); Beijing Hospital Institute of Geriatrics and National Center for Clinical Laboratories, Beijing (W. Chen, J. Li); Chinese Center for Disease Control and Prevention, Beijing (H. Yu, Y. Wang); The First Hospital of China Medical University, Shenyang, China (H. Shang)

Abstract

To determine sensitivity of rapid diagnostic tests for detecting influenza A(H7N9) virus, we compared rapid tests with PCR results and tested different types of clinical samples. Usefulness of seasonal influenza rapid tests for A(H7N9) virus infections is limited because of their low sensitivity for detecting virus in upper respiratory tract specimens.

On March 31, 2013, in China, novel avian influenza A(H7N9) virus infection was diagnosed in 3 persons (1). By October 2013, human infection with influenza A(H7N9) virus had reemerged; the number of cases in this second epidemic wave exceeded that of the first wave (before October 2013) (2). As of March 10, 2014, the virus had caused 379 human cases and 135 human deaths during both epidemic waves in China (2). Because the sensitivity of currently available rapid diagnostic tests (RDTs) for detecting virus in clinical specimens from patients with A(H7N9) virus infection remains largely unknown, we evaluated the sensitivity and specificity of 6 such tests available in China for detecting A(H7N9) virus in different types of clinical specimens from infected patients.

Novel avian influenza A(H7N9) virus has become the most prevalent avian influenza virus strain affecting humans in China. Shortly after the March 2013 outbreak, a real-time reverse transcription PCR (rRT-PCR) for detection of A(H7N9) virus was developed by the Chinese National Influenza Center (3). Although rRT-PCR is now considered the standard laboratory-based assay for detecting influenza virus infections, because of its high sensitivity and specificity, it requires high-level laboratory expertise and might not be available in all locations. Thus, the usefulness of RDTs for detecting A(H7N9) virus infection requires assessment. The sensitivity of 6 RDTs has been evaluated in Australia by using a laboratory influenza A(H7N9) virus isolate shared by the Chinese National Influenza Center and the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, Australia (4). However, the suitability of RDTs for detecting A(H7N9) virus in clinical specimens from patients remains largely unknown. We therefore evaluated the sensitivity and specificity of 6 RDTs (Table 1) available in China for detecting A(H7N9) virus in different types of clinical specimens.

Dr. Y. Chen is a professor at the State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, and belongs to the Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, China. His research interests focus on diagnosis and treatment of emerging infectious diseases. Dr. D. Wang is a professor at the National Institute for Viral Disease Control and Prevention, China CDC. Her research focus is influenza surveillance.

Acknowledgments

We thank the National Health and Family Planning Commission of China, Nan-Shan Zhong, and the Chinese Society of Laboratory Medicine.

This study was supported by a special grant for the prevention and control of infectious diseases in China (2012ZX10004-210) and the Key Technologies R&D Program of China (2012BAI37B01).

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Suggested citation for this article: Chen Y, Wang D, Zheng S, Shu Y, Chen W, Cui D, et al. Rapid diagnostic tests for identifying avian influenza A(H7N9) virus in clinical samples. Emerg Infect Dis [Internet]. 2015 Jan [date cited]. http://dx.doi.org/10.3201/eid2101.140247

DOI: 10.3201/eid2101.140247

1These authors contributed equally to this article.