en میکروب شناسی Microbiology <p style="text-align: justify;"><em><strong>Background: </strong></em>In patients who are hepatitis B virus (HBV) DNA-positive, but HBV surface antigen (HBsAg) -negative, the infection is referred to as occult hepatitis B infection (OBI). Occult HBV infection is harmful when other liver diseases are present, and can aggravate liver damage in in patients with chronic liver diseases. In human immunodeficiency virus (HIV) infection the suppression of viral replication by the immune system might be inactivated, and classical HBV infection in OBI patients may occur. Health care professionals should be aware of OBI in HIV patients. The routine test for HBV infection in Iran is the enzyme-linked immunosorbent assay for the HBV surface antigen (ELISA HBsAg); therefore, the aim of this study was to evaluate the prevalence of OBI in Iranian HIV patients.</p> <p style="text-align: justify;"><em><strong>Methods:</strong></em> This cross-sectional study was conducted in 2012 on sera from all the known and accessible HIV patients in Jahrom and Fassa, two cities in southern Iran. All samples were tested for the HBsAg, HBV core antibody (HBcAb). All the results were analyzed using SPSS.</p> <p style="text-align: justify;"><em><strong>Results:</strong></em> Of the 91 patients, seven (7.7%) were HBsAg-positive and forty-five (49.5%) were HBcAb-positive. In patients with negative HBsAg (84 patients), 39 (46.4%) were HBcAb positive and 53 (63%) were positive for HBV DNA.</p> <p style="text-align: justify;"><em><strong>Conclusion:</strong></em> The prevalence of HBV infection is relatively high in HIV patients, and more accurate tests than those presently in use should be used for diagnosis.</p> Hepatitis B, HIV infection, Occult hepatitis 38 42 http://rbmb.net/browse.php?a_code=A-10-1-35&slc_lang=en&sid=1 Arezoo Honarmand 10031947532846006035 10031947532846006035 No Microbiology Department, Islamic Azad University of Jahrom, Jahrom, Iran Morteza Pourahmad Mortezapourahmad@yahoo.com 10031947532846006036 10031947532846006036 Yes Internal Medicine Department, Jahrom University of Medical Sciences, Jahrom, Iran Kavous Solhjoo 10031947532846006037 10031947532846006037 No Microbiology Department, Jahrom University of Medical Sciences, Jahrom, Iran Mahmoud Kohan 10031947532846006038 10031947532846006038 No Nursery Department, Alborz University of Medical Sciences Mohamad Hassan Davami 10031947532846006039 10031947532846006039 No Microbiology Department, Jahrom University of Medical Sciences, Jahrom, Iran Seyed Kamyar Mostafavi Zadeh 10031947532846006040 10031947532846006040 No Infectious disease Department, Isfahan University of Medical Sciences, Isfahan, Iran