HWN Suggests

Dormant viruses can hide in our DNA and be passed from parent to child

During our early childhoods, the vast majority of us are boarded by a stowaway that can stay with us for the rest of our lives. It can rear its head when we are at our weakest and it can wriggle its way down our family tree into our children and grandchildren. It’s a virus called human herpesvirus-6, or HHV-6 for short. It’s probably in your genome right now. As its name suggests, HHV-6 is one of the herpesviruses. Unlike other members, it doesn’t actually cause herpes, but it is one of the most common infections in the Western world. It infiltrates the bodies of over 90% of children and it causes a near-universal disease called ‘exanthema subitum’, also known as roseola or three-day fever.…

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 Human Herpesvirus 6: An Emerging Pathogen

Infections with human herpesvirus 6 (HHV-6), a ß-herpesvirus of which two variant groups (A and B) are recognized, is very common, approaching 100% in seroprevalence. Primary infection with HHV-6B causes roseola infantum or exanthem subitum, a common childhood disease that resolves spontaneously. After primary infection, the virus replicates in the salivary glands and is shed in saliva, the recognized route of transmission for variant B strains; it remains latent in lymphocytes and monocytes and persists at low levels in cells and tissues. Not usually associated with disease in the immunocompetent, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed, typically AIDS patients and transplant recipients, in whom HHV-6 infection/reactivation may culminate in rejection of transplanted organs and death.

Articles of Interest

Alzheimer's link to herpes virus in brain, say scientists

Research reveals strains of virus more abundant in brains with early stage of disease, though uncertain whether virus is a trigger or a symptom.

Childhood Virus May Have a Role in Alzheimer’s Disease

A study of 1,000 brains found two common types of herpes viruses were more prevalent in those suffering from the dementia-inducing disease.

Human Herpesvirus 6

Human herpesvirus 6 (HHV-6) refers to a group of double-stranded DNA viruses comprising HHV-6A and HHV-6B, which are now recognized as distinct members of the herpesvirus family. HHV-6B is the known cause of exanthema subitum, or roseola infantum, a common self-limiting illness in young children. In contrast, HHV-6A is less understood but more frequently associated with serious disease in immunocompromised individuals. Among these patients, HHV-6 infection may present with neurologic or behavioral changes, with or without the classic rash.

Human Herpesvirus-6 and -7 (HHV-6 and HHV-7)

HHV-6 and HHV-7 are lymphotropic β-herpesviruses that usually infect humans within the first few years of life. Primary infection is asymptomatic or manifests as febrile childhood illnesses including exanthem subitum and results in life-long latency as seen with other herpesviruses. Seroprevalence rates in adults are over 90% (1,2). Therefore, in adults, most infections after transplant are likely due to reactivation of endogenous latent virus.

Human Herpesviruses 6 and 7 and Central Nervous System Infection in Children

Human herpesvirus (HHV)-6 and HHV-7 are ubiquitous T-lymphotropic viruses that infect most humans. Infections with either agent occur primarily during childhood.

Human Herpesviruses 6, 7, and 8 From a Dermatologic Perspective

The identified disease association of HHV-6 and HHV-7 is roseola infantum, also known as exanthem subitum, which develops in only a few infected children. A more debated association of the 2 viruses is pityriasis rosea.

More evidence supporting the role of HHV-6 and HHV-7 as possible triggers of pityriasis rosea

Pityriasis rosea (PR) is a skin condition of sudden onset that usually disappears over several weeks. First, a rose-colored “herald patch” with scaling borders appears, usually on the trunk. This is followed 1-2 weeks later by multiple small oval-shaped lesions on the trunk and limbs that often are very itchy. It long has been assumed that PR is likely caused by viral infection, but evidence of that has been relatively weak. However, over the past 5-10 years, reports from multiple laboratories have suggested that both HHV-6 and HHV-7 are linked to PR

Newly Found Herpes Virus Is Called Major Cause of Illness in Young

Further study has shown that the virus, which was renamed in part because it was found to belong to the herpes family, infects most children by the age of 3 and occurs throughout the world. But doctors have been puzzled by the spectrum of symptoms that it produces. Studies in Japan have linked HHV-6 to roseola, an illness characterized by a rash and high fever that can reach 106 degrees. As the fever disappears, the rash comes on and then usually fades rapidly. Roseola, also known as exanthem subitum, tends to strike children under the age of 4, often at 1 year. It tends to occur in spring.

Researchers Find Herpes Viruses In Brains Marked By Alzheimer's Disease

The team found that levels of two human herpes viruses, HHV-6 and HHV-7, were up to twice as high in brain tissue from people with Alzheimer's. They confirmed the finding by analyzing data from a consortium of brain banks. These herpes viruses are extremely common, and can cause a skin rash called roseola in young children. But the viruses also can get into the brain, where they may remain inactive for decades.

Roseola (Human Herpesvirus 6 and 7)—Child Care and Schools

Red, raised rash lasting from hours to several days that becomes apparent the day the fever breaks (usually the fourth day). Incubation period: 9 to 10 days for human herpesvirus 6; incubation for human herpesvirus 7 is unknown.

The herpes virus dilemma in Alzheimer’s disease

Surprisingly, when Liu and Jeong reanalyzed the data sets from the 2018 study using identical statistical methods with rigorous filtering, as well as four commonly used statistical tools, they were unable to produce the same results.

Update on Human Herpesvirus 6 Biology, Clinical Features, and Therapy

Human herpesvirus 6 (HHV-6) is a betaherpesvirus that is closely related to human cytomegalovirus. It was discovered in 1986, and HHV-6 literature has expanded considerably in the past 10 years.

Resources

HHV-6 Foundation

The Foundation sponsors international conferences and supports scientists and clinicians seeking to clarify the role of the two HHV-6 viruses in disease. Since HHV-6A and HHV-6B can smolder in the brain and other organs without circulating in the peripheral blood or plasma, identifying chronic infection is a challenge.