Hepatitis B virus (HBV) by PCR

Test code: S0033 - Ultrasensitive qualitative detection of hepatitis B virus by real time PCR

Infection with hepatitis B virus (HBV) is a major global health problem, and is estimated to account for approximately one million deaths from chronic liver disease and hepatocellular carcinoma each year. Although hepatitis virus B was found exclusively in human population and seemed to be specific to humans, a few studies have indicated a wide prevalence in non-human primates (Bancroft et al., 1977; Grethe et al., 2000; Heckel et al., 2001; Kessler et al., 1982; Lanford et al., 2000), especially primates in captivity. Some cases of HBV infection of non-human primates have been traced back to contamination by humans. In the wild, HBV infection has been documented in chimpanzees (Pan troglodytes), gibbons (Hylobates spp.), orangutan (Pongo pygmaeus) and gorilla (Gorilla gorilla).

Serological testing to detect HBV is not very reliable. Numerous authors have reported the existence of sera that are HBsAg negative, but HBV DNA PCR positive. For example, Blum et al. (1991) observed that the HBV genome in one such patient had numerous mutations, which resulted in low levels of HBsAg production, absence of HBeAg production, and a defect that terminated virus replication. Michalak et al. (1994) documented that the HBsAg-negative PCR-positive state could last for at least 5 years, and that the HBV particles actually existed as naked core particles but with intact virions, presumably in the form of immune complexes. Rehermann et al. (1996) also found that PCR positivity could persist for at least 23 years after the disappearance of HBsAg. Thus, serological testing can result in false negative results. However, PCR detection of HBV DNA is now regarded as the most appropriate method to confirm the presence of HBV DNA.

Utilities:

• Help confirm the disease causing agent
• Help ensure that animal colonies are free of Hepatitis B
• Early prevention of spread of this virus among a colony
• Minimize personnel exposure to this virus
• Safety monitoring of biological products and vaccines that derive from primates

References:
Bancroft, W.H., Snitbhan, R., Scott, R.M., Tingpalapong, M., Watson, W.T., Tanticharoenyos, P., Karwacki, J.J. and Srimarut, S. (1977) Transmission of hepatitis B virus to gibbons by exposure to human saliva containing hepatitis B surface antigen. J. Infect. Dis. 135:79-85.
Blum, H.E., Liang, T.J., Galun, E. and Wands, J.R. (1991) Persistence of hepatitis B viral DNA after serological recovery from hepatitis B virus infection. Hepatology 14:56-63.
Grethe, S., Heckel, J.O., Rietschel, W. and Hufert, F.T.(2000) Molecular epidemiology of hepatitis B virus variants in nonhuman primates. J. Virol. 74:5377-5381.
Heckel, J-O., Rietschel, W. and Hufert, F.T. (2001) Prevalence of hepatitis B virus infections in nonhuman primates. J. Med. Primatol. 30: 14-19.
Kessler, H., Tsiquaye, K.N., Smith, H., Jones, D.M. and Zuckerman, A.J. (1982) Hepatitis A and B at the London Zoo. J. Infect. Dis. 4: 63-67.
Lanford, R.E., Chavez, D., Rico-Hesse, R. and Mootnick, A.(2000) Hepadnavirus infection in captive gibbons. J. Virol. 74: 2955-2959.
Makuwa, M., Souquiere, S., Telfer, P., Leroy, E., Bourry, O., Rouquet, P., Clifford, S., Wickings, E.J., Roques, P. and Simon, F. (2003) J. Med. Primatol. 32:307-14.
Michalak, T.I., Pasquinelli, C., Guilhot, S. and Chisari, F.V. (1994) Hepatitis B virus persistence after recovery from acute viral hepatitis. J. Clin. Invest. 93:230-9.
Rehermann, B., Ferrari, C., Pasquinelli, C. and Chisari, F.V. (1996). The hepatitis B virus persists for decades after patients' recovery from acute viral hepatitis despite active maintenance of a cytotoxic T-lymphocyte response. Nat. Med. 2:1104-8.

Specimen requirement: 0.2 ml whole blood in EDTA (purple top) tube, or 0.2 ml plasma or serum, or 0.2 ml fresh, frozen or fixed liver tissue.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected