Seroprevalence and molecular characterization of viral hepatitis and HIV co-infection in the Central African Republic

Abstract

Background: The Central African Republic (CAR) is one of the countries with the highest prevalence of viral hepatitis infection in the world. Coinfection with HIV increases the morbidity and mortality beyond that of mono-infection with either hepatitis or HIV. The present study describes the geographic distribution of viral hepatitis infections and molecular characterization of these viruses in the CAR.

Methodology: Out of 12,599 persons enrolled during the fourth Multiple Indicator Cluster Survey of 2010 in the CAR, 10,621 Dried Blood Spot (DBS) samples were obtained and stored at -20°C. Of these DBS, 4,317 samples were randomly selected to represent all regions of the CAR. Serological tests for hepatitis B, D, and C viruses were performed using the ELISA technique. Molecular characterization was performed to identify strains.

Results: Of the 4,317 samples included, 53.2% were from men and 46.8% from women. The HBsAg prevalence among participants was 12.9% and that HBc-Ab was 19.7%. The overall prevalence of HCV was 0.6%. Co-infection of HIV/HBV was 1.1% and that of HBV/HDV was 16.6%. A total of 77 HBV, 6 HIV, and 6 HDV strains were successfully sequenced, with 72 HBV (93.5%) strains belonging to genotype E and 5 (6.5%) strains belonging to genotype D. The 6 HDV strains all belonged to clade 1, while 4 recombinants subtype were identified among the 6 strains of HIV.

Conclusion: Our study found a high prevalence of HBV, HBV/HDV and HBV/HIV co-infection, but a low prevalence of HCV. CAR remains an area of high HBV endemicity. This study's data and analyses would be useful for establishing an integrated viral hepatitis and HIV surveillance program in the CAR.

Fig 1. Flowchart of the different stages of randomization of tested samples.

Fig 2. Circulation of viruses and their genotypes in CAR.

All four viruses were present in the southeastern part of the Country. Bangui, the capital city, is affected by all three viruses and the circulation of the two genotypes (D and E) of HBV. This map was created with QGIS software, https://www.qgis.org/fr/site/ from the CAF shapefile downloaded from https://data.humdata.org/dataset/cod-ab-caf).

Fig 3. Phylogenetic analyses of 77 HBV strains with their GenBank accession number.

The tree was constructed in MEGA using the Neighbor-joining statistical method, the Kimura-2 parameter model, and the bootstrap method of 1000 replicates. The black circles represent reference sequence genotypes A-H downloaded from the database. The remaining are HBV sequences discussed in the present study, and the two genotypes (E and D) are noted on the tree.

Fig 4. Phylogenetic analyses of the 6 HDV strains.

The tree was constructed in MEGA using the Neighbor-joining statistical method, the Kimura-2 parameter model, and the bootstrap method of 1000 replicates. The black circles represent the HDV sequences discussed in the present study, and the remaining are the reference sequences with the country names.