A new enzyme immunoassay for the detection of antibody to hepatitis E virus

Hepatitis E virus (HEV), the causative agent of hepatitis E, has been reported in a wide variety of animals, including birds, but little is known of HEV infection in pet birds in northwest China. The objective of the present investigation was to examine HEV seroprevalence in three species of pet birds, namely, Eurasian siskin, Oriental skylark, and black-tailed grosbeak from Gansu. Serum samples collected from 685 pet birds from August 2011 to September 2012 were examined independently for the presence of antibodies against HEV. A total of 59 (8.31%) pet birds were tested positive for HEV antibodies by the commercially available enzyme immunoassay kits. Of these, the seroprevalence was diverse in different species pet birds; the most frequent level was 10.83% (39/360) in Eurasian siskin, followed by 6.57% (19/289) in Oriental skylark, and 2.29% (1/36) in black-tailed grosbeak. Age and collecting region of pet birds were the main risk factors associated with HEV infection. The present study firstly revealed the seroprevalence of HEV infection in three species of pet birds in northwest China, which provided the baseline data for taking comprehensive countermeasures and measures for effectively preventing and controlling HEV infection in birds.

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Hepatitis E virus ORF3 antigens derived from genotype 1 and 4 viruses are detected with varying efficiencies by an anti-hev enzyme immunoassay

Journal of Medical Virology ◽

10.1002/jmv.22032 ◽

2011 ◽

Vol 83 (5) ◽

pp. 827-832 ◽

Cited By ~ 12

Author(s):

Hongxia Ma ◽

Xiaoguo Song ◽

Tim J Harrison ◽

Heqiu Zhang ◽

Weijin Huang ◽

...

Keyword(s):

Enzyme Immunoassay ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Genotype 1

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IgM and IgG antibodies to hepatitis E virus (HEV) detected by an enzyme immunoassay based on an HEV-specific artificial recombinant mosaic protein

Journal of Medical Virology ◽

10.1002/(sici)1096-9071(199609)50:1<50::aid-jmv10>3.0.co;2-1 ◽

1996 ◽

Vol 50 (1) ◽

pp. 50-58 ◽

Cited By ~ 49

Author(s):

M. O. Favorov ◽

Y. E. Khudyakov ◽

E. E. Mast ◽

T. L. Yashina ◽

C. N. Shapiro ◽

...

Keyword(s):

Enzyme Immunoassay ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Igg Antibodies ◽

Mosaic Protein

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Quantitation of Immunoglobulin to Hepatitis E Virus by Enzyme Immunoassay

Clinical and Vaccine Immunology ◽

10.1128/cdli.9.3.639-648.2002 ◽

2002 ◽

Vol 9 (3) ◽

pp. 639-648 ◽

Cited By ~ 6

Author(s):

Bruce L. Innis ◽

Jitvimol Seriwatana ◽

Robin A. Robinson ◽

Mrigendra P. Shrestha ◽

Patrice O. Yarbough ◽

...

Keyword(s):

Enzyme Immunoassay ◽

Western Blotting ◽

Hepatitis E Virus ◽

Geometric Mean ◽

Hepatitis E ◽

World Health ◽

Confirmatory Test ◽

Reference Laboratory ◽

Operating Characteristics ◽

True Negative

ABSTRACT We developed a quantitative enzyme immunoassay (EIA) for antibody to hepatitis E virus (HEV) by using truncated HEV capsid protein expressed in the baculovirus system to improve seroepidemiology, to contribute to hepatitis E diagnosis, and to enable vaccine evaluations. Five antigen lots were characterized; we used a reference antiserum to standardize antigen potency. We defined Walter Reed antibody units (WR U) with a reference antiserum by using the four-parameter logistic model, established other reference pools as assay standards, and determined the conversion factor: 1 WR U/ml = 0.125 World Health Organization unit (WHO U) per ml. The EIA performed consistently; median intra- and intertest coefficients of variation were 9 and 12%, respectively. The accurate minimum detection limit with serum diluted 1:1,000 was 5.6 WR U/ml; the test could detect reliably a fourfold antibody change. In six people followed from health to onset of hepatitis E, the geometric mean antibody level rose from 7.1 WR U/ml to 1,924.6 WR U/ml. We used the presence of 56- and 180-kDa bands by Western blotting as a confirmatory test and to define true-negative and -positive serum specimens. A receiver-operating characteristics plot identified 30 WR U/ml as an optimum cut-point (sensitivity, 86%; specificity, 89%). The EIA detected antibody more sensitively than a commercially available test. The EIA was transferred to another laboratory, where four operators matched reference laboratory results for a panel of unknowns. Quantitation of antibody to HEV and confirmation of its specificity by Western blotting make HEV serology more meaningful.

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Development and Optimization of an Enzyme Immunoassay to Detect Serum Antibodies against the Hepatitis E Virus in Pigs, Using Plant-Derived ORF2 Recombinant Protein

Vaccines ◽

10.3390/vaccines9090991 ◽

2021 ◽

Vol 9 (9) ◽

pp. 991

Author(s):

Katerina Takova ◽

Tsvetoslav Koynarski ◽

George Minkov ◽

Valentina Toneva ◽

Eugenia Mardanova ◽

...

Keyword(s):

Enzyme Immunoassay ◽

Capsid Protein ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Blocking Agent ◽

Oral Route ◽

Youden Index ◽

Common Source ◽

Kappa Index ◽

Pig Serum

Hepatitis E is an emerging global disease, mainly transmitted via the fecal–oral route in developing countries, and in a zoonotic manner in the developed world. Pigs and wild boar constitute the primary Hepatitis E virus (HEV) zoonotic reservoir. Consumption of undercooked animal meat or direct contact with infected animals is the most common source of HEV infection in European countries. The purpose of this study is to develop an enzyme immunoassay (EIA) for the detection of anti-hepatitis E virus IgG in pig serum, using plant-produced recombinant HEV-3 ORF2 as an antigenic coating protein, and also to evaluate the sensitivity and specificity of this assay. A recombinant HEV-3 ORF2 110-610_6his capsid protein, transiently expressed by pEff vector in Nicotiana benthamiana plants was used to develop an in-house HEV EIA. The plant-derived HEV-3 ORF2 110-610_6his protein proved to be antigenically similar to the HEV ORF2 capsid protein and it can self-assemble into heterogeneous particulate structures. The optimal conditions for the in-house EIA (iEIA) were determined as follows: HEV-3 ORF2 110-610_6his antigen concentration (4 µg/mL), serum dilution (1:50), 3% BSA as a blocking agent, and secondary antibody dilution (1:20 000). The iEIA developed for this study showed a sensitivity of 97.1% (95% Cl: 89.9–99.65) and a specificity of 98.6% (95% Cl: 92.5–99.96) with a Youden index of 0.9571. A comparison between our iEIA and a commercial assay (PrioCHECK™ Porcine HEV Ab ELISA Kit, ThermoFisher Scientific, MA, USA) showed 97.8% agreement with a kappa index of 0.9399. The plant-based HEV-3 ORF2 iEIA assay was able to detect anti-HEV IgG in pig serum with a very good agreement compared to the commercially available kit.

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