HERPES

Human Herpesvirus 7

HHV-7

In 1990, four years after the isolation of HHV-6, another herpesvirus was discovered. Because of the similarities in genes HHV-6 and HHV-7 and the fact that HHV-7 often acts together with HHV-6, and the viruses together are sometimes referred to as Roseolovirus. HHV-7 has been found to cause at least some cases of exanthem subitum (roseola).

Antibodies to HHV-7 have been detected in 95% of the normal population. Over 75% were infected before six years of age. The primary infection of HHV-7 among children usually occurs between the ages of 2 and 5. This infers that the infection occurs after the primary infection of HHV-6, which is usually before 2 years of age.

It is believed that HHV-7 can contribute to the development of drug-induced hypersensitivity syndrome, hemiconvulsion-hemiplegia-epilepsy syndrome, encephalopathy, hepatitis, postinfectious myeloradiculoneuropathy, pityriasis rosea, and can reactive HHV-4, the Epstein-Barr Virus (EBV). Complications with HHV-7 infection have also been shown to be a factor in organ transplants.

What are the Symptoms for HHV-7?

There is no childhood disease or a definable syndrome that is associated with an acute HHV-7 infection. Both HHV-6B and HHV-7, as well as other viruses, can cause a rash roseola infantum in infants, but HHV-6B more than HHV-7. Even though there are usually no symptoms present with HHV-7, the infection is also associated with symptoms including acute febrile respiratory disease, fever, rash, vomiting, diarrhea, low lymphocyte counts, and febrile seizures.

How is HHV-7 Transmitted?

The virus seems to be spread through saliva.

It has been established that HHV-7 infection is widespread among populations in the USA, Europe and Japan.

How do you Test for HHV-7?

No reliable serological test has been developed yet for HHV-7 separate from HHV-6, but many are in the process of being developed.

What is the Treament for HHV-7?

No treatment for HHV-7 infection exists.