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Gaza F. Salih * and Kameran M. Ali **

*  Faculty of Science, Department of Biology, Sulaimani University, Sulaimani, Iraq.
** Kalar Technical Institute, MLT Dept, Sulaimani Polytechnic University, Farmanbaran, Kalar, Sulaimani, Iraq.

Submitted: 15/1/2015; Accepted: 9/6/2015Published 1/12/2015



Diagnosis of hepatitis B virus (HBV) infection is routinely based on the serological assay of hepatitis B surface antigen (HBsAg) detection. However, detection of HBV DNA has been documented from HBsAg negative samples. Occult hepatitis B virus infection is generally defined as the detection of HBV DNA in the serum or tissues of subjects who have negative test for HBsAg.


The aim of this study was to determine the rate of occult HBV infection among HBsAg negative subjects and the introducing of PCR as a diagnostic tool for HBV.


Serum samples from thalassemic patients and blood donors, previously tested for HBsAg by ELISA technique, were examined for the presence of HBV DNA by PCR in Kurdistan Technology and Scientific Research Establishment Center. PCR has been used due to its high specificity and sensitivity.


HBV DNA was detected in 11 (100%) thalassemic patients, who had detectable HBsAg while from 29 HBsAg negative blood samples, 7 samples (24.14%) were positive 
between PCR and ELISA tests in detecting HBV markers. Statistically, ELISA had showed (61%) sensitivity when compared to PCR technique in detecting PCR positive HBV DNA sera samples. However, it showed (100%) specificity in detecting PCR negative HBV-DNA samples. Furthermore, no significant association was observed according to sex effects on the incidence of HBV infection.


These results indicated that HBV DNA was observed in HBsAg negative patients. In addition, the present study showed that using of PCR in detection of the virus in patient’s samples is more sensitive than the ELISA assay.


Hepatitis B Virus, PCR, ELISA.


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