Little is known about the evolutionary history and origin of Hepatitis B Virus. Recent research confirms the idea that Hepatitis B Virus has existed in humans for centuries. Scientists extracted genomic data extracted from the mummified remains of a child buried in the Basilica of Saint Domenico Maggiore in Naples (Italy).
. In fact, this was the oldest evidence for the presence of smallpox in Medieval remains and a critical time stamp for its origins.
Using advanced sequencing techniques, researchers now suggest otherwise: the child was actually infected with Hepatitis B Virus. Interestingly, children infected with Hepatitis B Virus infections can develop a facial rash, known as Gianotti-Crosti syndrome. This may have been misidentified as smallpox and illustrates the difficulties of identifying infectious disease in the past.
Using small tissue samples of skin and bone, scientists were able to tease out tiny fragments of DNA and then stitch together pieces of genetic information to create a much more complete picture.
While viruses often evolve very rapidly - sometimes in just days - researchers suggest that this ancient strain of Hepatitis B Virus has changed little over the last 450 years and that the evolution of this virus is complex.
The team found a close relationship between the ancient and modern strains of Hepatitis B Virus, but both are missing what is known as temporal structure. In other words, there is no measurable rate of evolution throughout the 450-year period which separates the mummy sample from modern samples.
 Patterson Ross et al: The paradox of HBV evolution as revealed from a 16th century mummy in PloS Pathogens - 2018
 Marennikova et al: Smallpox diagnosed 400 years later: results of skin lesions examination of 16th century Italian mummy in Journal of Hygiene, Epidemiology, Microbiology and Immunology - 1990