In vitro studies confirm that the two viruses infect different cell types, and generate different cytopathic effects, cytokine and growth factor responses.
Similar prevalence of HHV-6A and HHV-6B found in African HIV+ patients
Prevalence of HHV-6A and HHV-6B was evenly divided in HIV+ patients in Western Africa, with over 6.3% positive for HHV-6 A and 5.0% for HHV-6B. HHV-6A was more common among those with a low viral HIV viral load.
Blood virome sequencing reveals new data on roseolovirus prevalence and epidemiology
Sequencing of over 8,000 individuals were used to determined the prevalence of 94 different viruses. HHV-7 was the most common virus, with HHV-6B and HHV-6A 4th and 5th respectively.
In Japan, inherited ciHHV-6A likely derived from common ancestor
A team in Japan has reports that ciHHV-6A prevalence is influenced by a “founder effect” and is likely derived from a common ancestor. All of the individuals in the small study were found to have HHV-6A integrated into the telomeric region of chromosome 22, a common site of integration.
HHV-6B saliva viral loads peak 3-7 months after primary infection
A new study on HHV-6B shedding in saliva during and after exanthema subitum found that peak detection rates and viral loads occurred during the convalescent period, between 3 to 7 months post-illness. Detection rates were lower in adults than in children suggesting that siblings may be more likely to transmit the virus than parents.
76% of Ugandan infants acquire HHV-6B in the first year
A new study led by Soren Gantt, MD from the University of British Columbia and Lawrence Corey, MD of the University of Washington revealed risk factors for transmission and symptoms of primary human herpesvirus infections among Ugandan infants.
Prevalence of betaherpesviruses in Sub-Saharan Africa
A group from University College London and the University of Zambia has reported that 20.5% of hospitalized infants were positive for HHV-6B, second only to CMV (24.3%). In contrast to previous studies, HHV-6A was found in only 0.3% of patients.
REVIEW: Important differences between the HHV-6A and HHV-6B viruses
An international group of experts summarize the significant differences between the two viruses.