Background:  Occult hepatitis B infection (OBI), defined as the presence of hepatitis B virus (HBV) DNA in liver or serum despite the absence of detectable hepatitis B surface antigen (HBsAg) is a frequent contaminant with human immunodeficiency virus (HIV). HIV has a negative effect on HBV disease accelerating its natural course.
Objective: This study aimed to estimate the occurrence of OBI in Egyptian HIV-infected patients with isolated anti-HBc.
Methods: This cross-sectional study was conducted on 197 HIV infected patients. They were tested for HBsAg, Antibody to hepatitis B surface antigen (anti-HBs), antibody to HBV core antigen (anti-HBc), and CD4 count. Patients with sole anti-HBc were screened for HBV DNA by polymerase chain reaction (PCR).
Results: Among those patients, 13 (6.60%) were positive for HBsAg, 82 (41.62%) for anti-HBc and 70 (35.53%) for anti-HBs. Their corresponding median CD4 count was 310.00 cells/mm³, 497.50 cells/mm³ and 525.50 cells/mm³, respectively. Anti-HBc was the sole marker in 35 (17.77%) patients of whom 7 (20%) were HBV DNA positive indicating OBI. Most OBI patients were non-vaccinated against HBV. There was no significant statistical relationship between the presence of OBI and CD4 count, although most of them had CD4 count less than 500 cells/mm³.
Conclusion: The present study underscores the importance of OBI screening among HIV patients with isolated anti-HBc.