Serological characterization of occult hepatitis B Virus infection in Riyadh regional laboratory

Introduction: Hepatitis B virus (HBV) infection is a major global health problem, causing chronic hepatitis, cirrhosis, hepatocellular carcinoma (HCC) and other chronic liver diseases. HBV infection is endemic in many parts of Kingdom of Saudi Arabia. Occult HBV infection (OBI) is a challenging clinical problem characterized by the absence of Hepatitis B surface Antigen (HBsAg) and low viral DNA load. Aims: This study aim is to investigate an epidemiological survey for the prevalence of OBI among Saudi healthy general population and two of most common HBV infection risks, hemodialysis and HIV patients in Riyadh Regional Laboratory. Methods: Three groups of samples were tested. 5025 blood samples healthy group were collected from Saudi citizens for pre-marriage screening testing. Second group is comprised of 658 adult patients with end-stage renal disease undergoing regular hemodialysis. Third group is comprised from 479 patients who had been previously confirmed for HIV infection. Results: Of 5025 healthy people enrolled into the study, 212 (4.2%) seropositive for HBsAg and/or anti HBc. Of them, 114/212 (53.8%) resolved infection with detectable anti-HBs (>10 mIU/mL), and 58/212 (27.36 %) had active HBV infection with detectable HBsAg. While, 40/212 (18.9%) were defined as OBI and HBV DNA was detected in two OBI patients. In 658 hemodialysis (HD) patients, 196 (27.96%) seropositive for HBsAg and/or anti-HBc. Of them 122/196 (66.3%) resolved infection with detectable anti-HBs (>10 mIU/mL), and 17/196 (9.24%) with active HBV infection with detectable HBsAg. OBI only detected in 32/196 (17.4%), HBV DNA was detected in 3 patients. Lastly, in 479 HIV patients, 152 seropositive for HBsAg and/or anti HBc. Of them 11/152 (7.23%) had active HBV infection with detectable HBsAg and 78 (51.3%) resolved infection with detectable anti-HBs (>10 mIU/mL). OBI detected in 63/152 (41.4%) and only 6 patients showed HBV DNA was detected. There were no statistically significant differences in the OBI prevalence between healthy population and HD prevalence while showed significance difference in HIV OBI prevalence compared to healthy group. Conclusions: this study proof that OBI is frequently encountered among healthy and high risk group individuals in Saudi Arabia and more support should be provided for the vaccination especially of high-risk groups, such as HIV and HD patients.