INTENDED USE

Anti-HEV Pig IgG ELISA is an enzyme-linked immunosorbent assay intended for the detection of IgG antibodies to Hepatitis E Virus (HEV) in pig serum or plasma.

 INTRODUCTION

Hepatitis E virus (HEV) is enterically transmitted and has been found to occur in developing nations. Major outbreaks of HEV have occurred in Asia, the former Soviet Union, Central America, and Africa. The course of the disease is generally acute and self-limiting without development of chronic sequelae. There is however, a high incidence of mortality (10-20%) in pregnant women and a mortality rate of 1-2% in the general population, which is 10 times higher than that of HAV. 

HEV has been detected in Taiwan and the preserved epitopes during the immune response after infection has been determined. The recent identification of swine HEV in pigs and the demonstration of its ability to infect across species have lent credence to the hypothesis that animals may be the source of infection. The swine HEV IgG ELISA utilizes these synthetic HEV antigens from the structural region of the viral genome of Taiwanese strains to detect the presence of HEV antibodies (IgG) in pig sera or plasma and was shown to be able to detect all antibody induced by most HEV strains in the world.

PRINCIPLES OF THE PROCEDURE

The wells of the polystyrene microplate strips are coated with three synthetic HEV antigens, which are respond to the structural regions of the Hepatitis E Virus. Pig serum or plasma, diluted in diluent buffer, and are incubated in these coated wells. HEV specific antibodies, if present, will bind to the solid phase HEV antigens. The wells are thoroughly washed to remove unbound materials and an affinity-purified anti-swine IgG labelled with horseradish peroxidase is added to the wells. This labelled antibody will bind to any antigen-antibody complexes previously formed and excess unbound labelled antibodies are removed by washing. A substrate solution containing hydrogen peroxide and 3,3’,5,5’-tetramethylbenzidine (TMB) is then added to each well. The presence of specific antibodies is indicated by the presence of a blue colour after substrate addition. Unstopped TMB is read at 650nm. If reaction is terminated by addition of sulphuric acid, the intensity of the colour can be measured spectrophotometrically at 450nm and is proportional to the amount of antibodies present in the specimen.

KIT COMPNENTS

1. Microplate                                    1 plate with 12 strips (96 wells)

2. Positive Control                            1 vial (30 µl)

3. Negative Control                          1 vial (30 µl)
 
4. Conjugate                                    1 vial (30 µl)

5. Detergent                                     1 vial (30 ml)

6. Wash Buffer powder                    2 x

7. Substrate Buffer                            1 capsule

8. Substrate Tablets                          2 Tablets

9. Plate Covers                                 4 pieces

10. Instruction Manual                      1 copy

REFERENCES

1. Balayan, M.S., A.G. Andzhapandze, S.S. Savinskaya, E.S. ketiladze, D.M. Braginski, A.P. Savinow, V.F. poleschuk. 1983. Evidence for a virus in non-A, non-B hepatitis transmitted via the fecal oral route. Intervirology 20:23.

2. Bradley, D.W.1990. Enterically transmitted non-A, non-B hepatitis. Pp 442-461. In A.J. Zuckerman (ed) British Medical Bulletin 46(2). Churchill Livingstone, New York.

3. Purcell, R.H. and J.R. Ticehurst. 1988. Ebterically transmitted non-A, non-B hepatitis: Epidemiology and clinical characterisitis. Pp. 131-137. In A.J. Zuckerman (ed). Viral Hepatitis and Liver Disease. Alan R. Liss Inc., New York.

4. Cooper K, Huang FF, Batista L, Rayo CD, Bezanilla JC, Toth TE, Meng XJ. Identification of genotype 3 hepatitis E virus (HEV) in serum and fecal samples from pigs in Thailand and Mexico, where genotype 1 and 2 HEV strains are prevalent in the respective human populations, J.Clin.Microbiol 2005; 43: 1684-8

5. Meng XJ Wiseman B, Elvinger F, Guenette DK, Toth TE, Engle RE, Emerson SU, Purcell RH.. Prevalence of antibodies to hepatitis E virus in veterinarians working with swine and in normal blood donors in the United States and other countries, J. Clin. Microbiol. 2002; 40: 117-22.

6. Meng XJ, Purcell RH, Halbur PG, Lehman JR, Webb DM, Tsareva TS, Haynes JS, Thacker BJ, Emerson SU. A novel virus in swine is closely related to the human hepatitis E virus. Proc.Natl.Acad.Sci USA 1997; 94:9860-5

7. Wang CH. Hepatitis E virus infection: prevalence of anti-HEV neutralizing antibody. Epidemiology Bulletin (CDC, Taiwan, ROC) 2001:17; 301-26.

8. Lee CC, Shih YL, Laio CS, Lin SM, Huang MM, Chen CJ, Chen CP, Chang CL, Chen LR, Tschen SY, Wang CH. Prevalence of antibody to hepatitis E virus among haemodialysis patients in Taiwan: possible infection by blood transfusion. Nephron Clin Pract; 2005: 99:c122-7.