Intra Prison Transmission And Genetic Diversity Of Hepatitis B Virus In A Ghanaian Prison

Abstract

Background: Selecting an ideal genetic regions for the phylogenetic analysis of hepatitis B virus (HBV) transmission continue to be a matter of debate, with different researches preferring different genomic region. Whole genome sequence analysis is always the gold standard for this this kind of research. But in middle income countries such as Ghana, where HBV infections are endemic, it is almost impossible to study a large number of samples because of financial constraints. Thus, analysis of nonoverlapping, fast-evolving regions was recommended. Aim: This study determined the intra prison transmission and genetic diversity of hepatitis B virus among inmates in correctional facility in Ghana Methodology: Hepatitis B surface antigen (HBsAg) positive archived plasma samples from a Ghanaian prison which was part of a nationwide survey of HIV and HBV in correctional facilities was used for this study. HBV DNA was extracted from 26 archived plasma samples and the precore, core region, surface envelope gene and the preS1 and preS2 regions amplified. The Sanger method was used to sequence the S gene of 17 plasma samples, Precore/core gene of 8 samples and PreS1, PreS2 gene for 5 samples. Sequence Identity Matrix, phylogenetic analysis and mutational analysis were used to establish possible intra prison transmission within the selected prisons. Results: Sixteen out of the 17 successfully sequenced samples belonged to HBV genotype E with the exception of one sample (14S) harboured the A/E recombinant. Sequences from the same prison clustered together and identity matrix revealed a narrower similarity range for these sequences. Surprisingly sequences from the two different prisons that were added to the sample size of 24 were closely related to each other and also to some of the sequences of the major prison. Mutations were seen across all the regions of the genome that were amplified however this were not uniformly distributed in the samples. Sequences with Sequence Identity Matrix value close to 1 and were strongly related to each other using phylogenetic tree had common mutations across the various regions investigated. Of note is the presence of L209V mutation, L217R mutation and the vaccine escape mutation (M133L) in the S gene and W28* in the precore gene of two inmates. Conclusion: Recent infection, coupled with a similarity index value close to 1, clustering of sequences together and demographic data suggest that there is on-going intra prison transmission of HBV within inmates. Presence of common mutations may also be used as a means of establishing horizontal transmission within prison.