Bayesian inference of the evolution of HBV/E

Area of Science:

• * Virology
• * Evolutionary Biology
• * Epidemiology

Background:

• * Hepatitis B virus genotype E (HBV/E) is highly prevalent in sub-Saharan Africa.
• * HBV/E exhibits unusually low genetic diversity, suggesting a recent emergence.
• * Understanding the evolutionary history of HBV/E is crucial for public health.

Purpose of the Study:

• * To investigate the evolutionary origins and spread of HBV/E.
• * To determine the mutation rate and emergence timeline of HBV/E.
• * To elucidate the factors contributing to HBV/E's hyperendemicity in Africa.

Main Methods:

• * Extensive phylogeographic analyses were conducted.
• * Bayesian Markov Chain Monte Carlo (MCMC) modeling was employed.
• * Viral mutation rates and spread patterns were estimated.

Main Results:

• * A mutation rate of 1.9 × 10⁻⁴ substitutions per site per year was determined for HBV/E.
• * The emergence of HBV/E is estimated to be within the last 130 years, post-transatlantic slave trade.
• * Analyses suggest HBV/E originated in Nigeria and spread rapidly throughout sub-Saharan Africa.
• * Multiple introductions of HBV/E into Haiti occurred in the mid-20th century.
• * The hyperendemicity of HBV/E in Africa is a recent phenomenon linked to transmission changes.

Conclusions:

• * HBV/E is a relatively recent genotype in Africa, emerging within the last 130 years.
• * The origin of HBV/E is likely Nigeria, with subsequent rapid dissemination.
• * Recent changes in transmission routes have driven the hyperendemicity of HBV/E in Africa.