Hepatitis B virus genotypes A and D in Uganda

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.

Disproportionate Distribution of HBV Genotypes A and D and the Recombinant Genotype D/E in the High and Low HBV Endemic Regions of Uganda: A Wake-Up Call for Regional Specific HBV Management

BACKGROUND

Hepatitis B virus (HBV) is the leading cause of liver-related diseases. In Uganda, there is a regional disparity in the HBV burden. Our study was aimed at establishing the circulating genotypes in a low and a high endemic region to give plausible explanations for the differences in regional burden and guide the future management of the disease.

METHODS

A total of 200 HBsAg-seropositive subjects were recruited into the study by convenience sampling. The HBsAg Rapid Test Strip (Healgen Scientific Limited Liability Company, Houston, TX77047- USA) was used to screen for HBsAg while the Roche machine (Roche, Basel Switzerland/Abbot Technologies (USA)) was used to determine the viral load. The Chemistry Analyzer B120 (Mindray, China) was used for chemistry analysis. For HBV genotyping, total DNA was extracted from whole blood using the QIAamp® DNA extraction kit. Nested PCR amplification was performed using Platinum Taq DNA Polymerase (Invitrogen Corporation, USA) to amplify the 400 bp HBV polymerase gene. Purification of nested PCR products was performed using Purelink PCR product purification kit (Life Technologies, USA). Automated DNA sequencing was performed using BigDye Terminator v3.1 Cycle Sequencing Kit on 3130 Genetic Analyzer (Applied Biosystems, USA). The NCBI HBV genotyping tool (https://www.ncbi.nlm.nih.gov/projects/genotyping/formpage.cgi) was used for determination of genotype for each HBV sequence. Pearson's chi-square, multinomial logistic regression, and Mann-Whitney U tests were used for the analysis. All the analyses were done using SPSS version 26.0 and MedCalc software version 19.1.3 at 95% CI. A p < 0.05 was considered statistically significant.

RESULTS

Majority of our study subjects were female (64.5%), youth (51.0%), and married (62.0%). Overall, genotype A was the most prevalent (46%). Genotype D and the recombinant genotype D/E were proportionately more distributed in the high endemic (38.2%) and low endemic (36.5%) regions, respectively. Genotype D was significantly more prevalent in the high endemic region and among the elderly (p < 0.05). Genotype D was significantly associated with elevated viral load and direct bilirubin (p < 0.05). The recombinant genotype D/E was significantly associated with elevated viral load (p < 0.05). Similarly, genotype A was significantly associated with elevated AST and GGT, lowered viral load, and normal direct bilirubin levels (p < 0.05).

CONCLUSION

There is disproportionate distribution of genotypes A and D and the recombinant genotype D/E in the low and high endemic regions of Uganda. This probably could explain the differences in endemicity of HBV in our country signifying the need for regional specific HBV management and control strategies.

Early childhood transmission of hepatitis B prior to the first hepatitis B vaccine dose is rare among babies born to HIV-infected and non-HIV infected mothers in Gulu, Uganda

BACKGROUND

Hepatitis B (HBV) in sub-Saharan Africa is believed to be horizontally acquired. However, because of the high HBV prevalence in northern Uganda, no hepatitis B vaccination at birth and no access to HBV immunoglobulin, we hypothesize that vertical transmission also could also play an important role. We therefore investigated the incidence of HBV among babies presenting for their first HBV vaccine dose in Gulu, Uganda.

METHODS

We recruited mothers and their babies (at least 6-week old) presenting for their postnatal care and first HBV vaccine dose respectively. Socio-demographic and risk factors for HBV transmission were recorded. Mothers were tested for Hepatitis B core antibody (anti-HBc-IgG) and hepatitis B surface antigen (HBsAg). HBsAg-positive sera were tested for hepatitis B e antigen (HBeAg) and HBV viral load (HBVDNA). Babies were tested for HBsAg at presentation and at the last immunization visit. A sample of HBsAg-negative babies were tested for HBVDNA. Incident HBV infection was defined by either a positive HBsAg or HBVDNA test. Chi-square or fisher's exact tests were utilized to investigate associations and t-tests or Wilcoxon rank-sum test for continuous differences.

RESULTS

We recruited 612 mothers, median age 23years (IQR 20-28). 53 (8.7%) were HBsAg-positive and 339 (61.5%) were anti-HBc-IgG-positive. Ten (18.9%) of the HBsAg-positive mothers were HBeAg-positive. Median HBVDNA levels of HBV-infected mothers was 5.7log (IQR 4.6-7.0) IU/mL with 9 (17.6%) having levels≥10⁵IU/mL. Eighty (13.3%) mothers were HIV-infected of whom 9 (11.5%) were co-infected with HBV. No baby tested HBsAg or HBVDNA positive.

CONCLUSION

Vertical transmission does not seem to contribute substantially to the high HBV endemicity in northern Uganda. The current practice of administering the first HBV vaccine to babies in Uganda at six weeks of age may be adequate in control of HBV transmission.

High Prevalence and Diversity of Hepatitis Viruses in Suspected Cases of Yellow Fever in the Democratic Republic of Congo

The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 10⁵ IU/ml for HBV (range, 769 to 9.82 × 10⁹ IU/ml) and 1.4 × 10⁶ IU/ml for HDV (range, 3.1 × 10² to 2.9 × 10⁸ IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC.