Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 41 2 2012 02 15 100 104 E Gholami Parizad A Khosravi E Gholami Parizad N Sadeghifard S Ghafourian 2015 10 03 Background: It is estimated that about 370 million people are chronic carriers of HBV worldwide. Apparently 3% of Iranian populations are chronic carriers of this virus. We aimed to evaluate the viral DNA in biological fluids of chronic hepatitis patients compared to a control group. Methods: The current case-control study was designed to evaluate the viral DNA in biological fluids of 70 chronic hepatitis patients compared to a control group using ELISA, PCR and Real Time. Results: All individuals (100%) in case group were HBsAg positive while in control group only 2 individuals (2.8%) were HBsAg positive. Three individuals , in control group were positive using PCR and Real Time PCR indicating that about 7% of those in control  group were chronic carriers of HBV. The interesting point was the copy of viral DNA; (5.49 ×104, 2.162×103and 7.26×106) for 3 chronic carriers using sera while it was about (5.71×103, 1.45×102 and 2.56×105) using ear cerumen confirming the necessity of investigating for the carriers of HBV in different biological fluid and by different methods. Conclusion: It can be concluded chronic carriers of hepatitis B are much more than what is diagnosed by routine diagnostic tests. On the other hand ELISA alone can not be relied on as a complete test for screening of chronic carriers in hepatitis B. PCR and Real Time PCR are more reliable tests for this purpose. https://ijph.tums.ac.ir/index.php/ijph/article/view/2624 https://ijph.tums.ac.ir/index.php/ijph/article/download/2624/2604