A combination of serological assays to detect human antibodies to the avian influenza A H7N9 virus

• Published in: PloS one 2014-04, Vol.9 (4), p.e95612-e95612
• Main Authors: Dong, Libo, Bo, Hong, Bai, Tian, Gao, Rongbao, Dong, Jie, Zhang, Ye, Guo, Junfeng, Zou, Shumei, Zhou, Jianfang, Zhu, Yun, Xin, Li, Li, Xiaodan, Xu, Cuiling, Wang, Dayan, Shu, Yuelong
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antibodies; Antibodies, Viral - blood; Antibodies, Viral - immunology; Antibody response; Assaying; Avian flu; Avian influenza; Biology and life sciences; Care and treatment; Case-Control Studies; Child; Child, Preschool; Children; Comparative analysis; Diagnosis; Disease control; Disease prevention; Distribution; Erythrocytes; Family planning; Geriatrics; Health risks; Hemagglutination Inhibition Tests; Hemagglutinins; Humans; Illnesses; Immunoglobulins; Infections; Influenza; Influenza A; Influenza A virus - immunology; Influenza A Virus, H7N9 Subtype - immunology; Influenza, Human - diagnosis; Influenza, Human - immunology; Lectins; Medical laboratories; Medicine and Health Sciences; Middle Aged; Neutralization Tests; Older people; Orthomyxoviridae Infections - immunology; Pandemics; Physiological aspects; Public health; Reproducibility of Results; Sensitivity; Sensitivity and Specificity; Viral infections; Virology; Viruses; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0095612

Human infection with avian influenza A H7N9 virus was first identified in March 2013 and represents an ongoing threat to public health. There is a need to optimize serological methods for this new influenza virus. Here, we compared the sensitivity and specificity of the hemagglutinin inhibition (HI), microneutralization (MN), and Western blot (WB) assays for the detection of human antibodies against avian influenza A (H7N9) virus. HI with horse erythrocytes (hRBCs) and a modified MN assay possessed greater sensitivity than turkey erythrocytes and the standard MN assay, respectively. Using these assays, 80% of tested sera from confirmed H7N9 cases developed detectable antibody to H7N9 after 21 days. To balance sensitivity and specificity, we found serum titers of ≥20 (MN) or 160 (HI) samples were most effective in determining seropositive to H7N9 virus. Single serum with HI titers of 20-80 or MN titer of 10 could be validated by each other or WB assay. Unlike serum collected from adult or elderly populations, the antibody response in children with mild disease was low or undetectable. These combinations of assays will be useful in case diagnosis and serologic investigation of human cases.