Abstract:
HHV-7 first isolated in 1990 from a healthy individual, is a ubiquitous agent. The second independent isolation of HHV-7 from a chronic fatigue syndrome patient was reported in 1992. The seroepidemiology of HHV-7 suggested that its prevalence rate in the U.S.A. population is > 85%; however, in Japan a low prevalence rate has been reported. HHV-7 can be more readily isolated from the saliva than HHV-6. The primary infection of HHV-7 appears later in life than HHV-6. No disease has been reported that is etiologically linked to HHV-7. HHV-7 is more closely related to HHV-6 and the human cytomegalovirus than other members of the human herpesvirus family.
Source: Ablashi DV, Berneman ZN, Kramarsky B, Asano Y, Choudhury S, Pearson GR. Human herpesvirus-7 (HHV-7). In Vivo. 1994 Jul-Aug;8(4):549-54. http://www.ncbi.nlm.nih.gov/pubmed/7893982