Highlights from 5th International Conference on HHV-6 and -7.

This article reports on key presentations at the 5th International Conference on Human Herpesvirus (HHV)-6 and -7, organized by the HHV-6 Foundation. New assays for HHV-6 and -7 promise to be more accurate and better able to distinguish between HHV-6A and B or differentiate active from latent infection. Nevertheless, more research is needed to enhance the sensitivity and specificity of these assays. Cellular receptors for both HHV-6 and -7 have been identified. Both viruses have in vitro tropism for neurons and dendritic cells of the central nervous system (CNS), and their role in producing CNS disease in the immunocompromised (particularly transplant recipients and the HIV-infected) is well established. HHV-6 may enhance the progression of simian immunodeficiency virus in monkeys, as suggested by in vivo data. In immunocompetent children and adults, HHV-6 and/or -7 may play a role in triggering and perpetuating several diseases of the nervous system, namely encephalitis, multiple sclerosis, chronic fatigue syndrome and epilepsy.