Genetic and phylogenic characterization of hepatitis B virus in the eastern part of the Democratic Republic of Congo

Mapping hepatitis B virus genotypes on the African continent from 1997 to 2021: a systematic review with meta-analysis

Hepatitis B virus (HBV) has ten genotypes (A-J) and over 40 sub-genotypes based on the divergence of ≥ 8% and 4 to < 8% in the complete genome respectively. These genotypes and sub-genotypes influence the disease prognosis, response to therapy and route of viral transmission. Besides, infection with mixed genotypes and recombinant genotypes has also been reported. This study aimed at mapping the de novo genotypes and correlate them with the immigration trends in order to inform future research on the underlying reasons for the relative distribution of HBV genotypes from a large sample size pooled from many primary studies. Data was extracted from 59 full research articles obtained from Scopus, PubMed, EMBASE, Willy library, African Journal Online (AJOL) and Google Scholar. Studies that investigated the genotypes, sub-genotypes, mixed genotypes and recombinant were included. The Z-test and regression were used for the analysis. The study protocol is registered with PROSPERO under the registration number CRD42022300220. Overall, genotype E had the highest pooled prevalence significantly higher than all the other genotypes (P < 0.001). By region, genotype A posted the highest pooled prevalence in eastern and southern Africa, E in west Africa and D in north Africa (P < 0.0001). Regarding the emerging genotypes B and C on the African continent, genotype B was significantly higher in south Africa than C (P < 0.001). In contrast, genotype C was significantly higher in east Africa than west Africa (P < 0.0001). The A1 and D/E were the most diverse sub-genotypes and genotype mixtures respectively. Finally, we observed a general progressive decrease in the prevalence of predominant genotypes but a progressive increase in the less dominant by region. Historical and recent continental and intercontinental migrations can provide a plausible explanation for the HBV genotype distribution pattern on the African continent.

Seroepidemiology of Hepatitis B in the Democratic Republic of the Congo

Hepatitis B virus (HBV) is endemic throughout Africa, but its prevalence in the Democratic Republic of the Congo (DRC) is incompletely understood. We used dried blood spot (DBS) samples from the 2013 to 2014 Demographic and Health Survey in the DRC to measure the prevalence of HBV using the Abbott ARCHITECT HBV surface antigen (HBsAg) qualitative assay. We then attempted to sequence and genotype HBsAg-positive samples. The weighted national prevalence of HBV was 3.3% (95% CI: 1.8-4.7%), with a prevalence of 2.2% (95% CI: 0.3-4.1%) among children. Hepatitis B virus cases occurred countrywide and across age strata. Genotype E predominated (60%), and we found a unique cluster of genotype A isolates (30%). In conclusion, DBS-based HBsAg testing from a nationally representative survey found that HBV is common and widely distributed among Congolese adults and children. The distribution of cases across ages suggests ongoing transmission and underscores the need for additional interventions to prevent HBV infection.

Highly sensitive chemiluminescent aptasensor for detecting HBV infection based on rapid magnetic separation and double-functionalized gold nanoparticles

Hepatitis B virus (HBV) infection is a major global public health problem and one of the leading causes of chronic liver disease. HBsAg is the first serological marker to appear in the blood and is the most important marker of HBV infection. Detection of HBsAg in serum samples is commonly carried out using an immunoassay such as an enzyme-linked immunosorbent assay (ELISA), which is complex to perform, time-consuming, and unsatisfactory for testing sensitivity. Therefore, new methods for highly sensitive detection of HBV infection are urgently needed. Aptamers are specific recognition molecules with high affinity and specificity toward their targets. Biosensors that employ aptamers as biorecognition elements are known as aptasensors. In this study, we select an HBsAg-specific aptamer and use it to develop a new chemiluminescent aptasensor based on rapid magnetic separation and double-functionalized gold nanoparticles. This sensor enables rapid magnetic separation and highly sensitive detection of HBsAg in HBV-positive serum. The detection limit of this HBsAg-detecting chemiluminescent aptasensor is as low as 0.05 ng/mL, which is much lower than the 0.5 ng/mL limit of a typical ELISA used in hospitals. Furthermore, this aptasensor works well and is highly specific to HBV infection.