Profiling Hepatitis B Viral Load: Treatment and Epidemiological Implications in a West African Hospital

Background: Chronic hepatitis B virus (HBV) infection is one of the largest public health problems with nearly 350 million chronic carriers and 500,000 deaths each year. These deaths are most often associated with disease progression to cirrhosis or hepatocellular carcinoma, which some studies have shown is associated with long-term viral replication in chronic carriers. Viral load quantification, a key element of disease management, is expensive and difficult to access. Viral load plays a crucial role in patient classification and treatment initiation. Four years after the implementation of viral load platform, the objective of this study was to assess viral load profile in HBs chronic carriers in a sub-Saharan Hospital and to determine the potential impact of this distribution on preventive and therapeutic strategies against hepatitis B infection. Materials and Method: The study was carried out between April 2016 and October 2020 in the laboratory of the PRINCIPAL Hospital in Dakar. All patients referred for HBV DNA viral load testing following a positive AgHBs test were included. Incomplete medical records were excluded from the study. Only the first quantification test performed on each patient is recorded. DNA extraction was performed with COBAS AmpliPrep (Roche Molecular Systems, Inc., Branchburg, NJ, USA). Amplification was performed using COBAS TaqMan48 (Roche Molecular Systems, Inc., Branchburg, NJ, USA). Data were collected from the laboratory’s computer system and entered into Microsoft Excel (2007). Statistical analyzes were performed using Epi-Info 7 software. Results: A total of 3002 patients, 76.1% (2285/3002) men and 33.9% (717/3002) women, were included in the study. Young adults were most represented among the subjects (23.2%) and (20.1%) in the age groups 25 - 30 and 30 - 35. The majority (52.7%) of patients had viral loads between 20 and 2000 IU. Patients with undetectable viral loads and patients with viral loads below 20 IU comprised 14.6% and 7.53% of the study population, respectively. Patients with viral loads between 2000 and 20,000 IU/ml and those with viral loads greater than 20,000 IU/ml represented 16.3% and 8.89% of the study population, respectively. Viral load was higher in males than females, with corresponding median and interquartile ranges of 2.7 log IU (2.2, 2.75) and 2.23 log IU (2.1, 2.4) (p < 0.001). This viral load also decreases with age. There were more patients with an undetectable viral load over 30 years than those under 30 years, with a ratio of 1.62 (IC95% = 1.29 - 2.05) (p = 0.009). Conclusion: This study shows a successful implementation of virus quantification in the context of resource-constrained countries. The second finding of this study is the high prevalence of adolescents with high plasma viral loads, indicating the need for additional investigations to initiate therapy. The large population with a low HBV replication rate points to the problem of financing follow-up care for chronically infected people. Studying this population in the context of an unknown genomic profile indicates the need to deepen virological laboratory testing through a sequencing platform. Finally, regular viral load reporting in major hospital cities could be a powerful and accessible management tool for hepatitis B programs in resource-constrained countries.