Prevalence of overt and occult hepatitis B virus infections among 135 haemodialysis patients attending a haemodialysis centre at Al-Nasiriyah city, Iraq

The prevalence of Hepatitis B virus (HBV) infection among haemodialysis (HD) patients has been well documented. In addition to overt infection, occult Hepatitis B infection exists in which a patient who is diagnosed seronegative for Hepatitis B surface antigen (HBsAg) shows positive HBV-DNA on using more accurate molecular methods. This study aims to determine the prevalence of overt and occult HBV infection among the HD patients who had attended Al-Nasiriyah dialysis centre during a two-month period.

Serological qualitative detection of HBsAg by rapid test (strips), enzyme immunoassay (EIA, HBsAg) and molecular (real-time polymerase chain reaction (real-time PCR)) was conducted for quantitative detection of HBV in HD patients’ serum.

The prevalence of overt HBV infection among HD patients was 3.7%. The viral load of HBV positive patients was ranging from 5.85 × 101 to 2.16 × 106 copies/ml of serum with median (7.4 × 105 copies/ml). Occult Hepatitis B was not detected in any of the seronegative HD patients (0%). Overt infection was found more in males (80%) than females (20%) (P<0.05). Similarly, infection was found to be higher among patients who had blood transfusions (80%) than those who had not (20%) with statistical significant p<0.05. Although not statistically significant, the mean duration of HD was higher among HBV positive HD patients (17.6) than HBV negative HD patients (14.3). A dual infection of HBV and HCV was not detected in this study.

Nosocomial transmissions at HD centres and blood transfusion are important risk factors. Besides serological screening, real-time PCR offers a safeguard against the spread of overt and occult HBV infection and determines the viral load of the positive patients.