Prevalence of Human Herpesvirus -6 (HHV-6 ) and Human Herpesvirus - 7 (HHV-7) in Saliva of Health Individuals

Abstract

HHV-6 and HHV-7 are two recently isolated novel viruses from the Herpesvirus family. Two virus types of HHV-6 exist namely type A and B. HHV-6 is the etiologic agent for exanthem subitum of infants but little is known of HHV-7 in human disease. The presence of HHV-6 and HHV-7 was investigated by Polymerase Chain Reaction (PCR) in saliva specimens from healthy donors. Of 60 samples analysed, 83.3% of Malaysians and 66.7% of Vietnamese had viral DNA for both HHV-6 and HHV-7 in the saliva. It was found that 90.0% and 93.3% of Malaysians and 73.3% and 90.0% of Vietnamese were positive for HHV-6 and HHV-7, respectively. Restriction endonuclease digestion on HHV-6 DNA amplicons revealed that all samples from both populations were HHV-6 variant type B. The study shows that HHV-7 was more frequently prevalent in the saliva of both population. The results indicate that the saliva is the main source of the two viruses and that it plays a major role in their transmissions.