Occult Hepatitis B Virus: Implications in Endemic Region like Nigeria.

Abstract

The situation whereby there is appearance of HBV DNA in the absence of observable hepatitis B surface antigen (HBsAg) has been described as occult hepatitis B virus infection. The above situation was first mentioned in late 1970s and its prevalence depends on the differences in the distribution of HBV in each region or community, the study population, sensitivity and specificity of the adopted screening method. The sero-prevalence of HBsAg in Nigeria is estimated to range from 10-40% and this qualifies Nigeria as hyper- endemic area (Odemuyiwa et al., 2001; Fasola et al., 2008). There is also observable increase in detected HBV DNA among patients who were previously screened as negative for HBsAg (Adeniyi et al., 2022). Furthermore, high prevalence of HBsAg has been reported in the population of screened blood donors (Ejele and Ojule, 2004) and also in patients attending clinics (Nwokedi et al, 2011; Adeniyi et al., 2022). Occult HBV is clinically important as it can be contacted by means of blood transfusion and organ transplant among others (Kwak et al., 2014). In Nigeria, there has being increase in prevalence of occult HBV despite ongoing immunization program (Opaleye et al., 2015; Adeniyi et al., 2002). When compared to similar viruses that could be transmitted during transfusion, occult HBV is more common (Comanor et al., 2006).