Deadly danger

Herpes viruses infect the brain with gene mutations

As a rule, the herpes virus causes unpleasant but harmless infections: Cold sores that disappear on their own. In a few people, however, the infection can spread to the central nervous system and cause encephalitis, a severe inflammation of the brain.

In young children, diagnosis is often difficult and without early antiviral treatment, encephalitis can cause severe neurological damage or death. A weakness in the immune system allows normally harmless herpes viruses to trigger life-threatening inflammation of the brain in rare cases.

Researchers at Lausanne University Hospital (Chuv) have identified a genetic cause linked to interferon production in conjunction with other factors for this weakness, as they reported in a study in the journal "Nature". This discovery expands the catalog of genetic tests that could be offered to people at risk, the Chuv said.

Virus has an easy time without interferons
Interferons are part of the immune system. They are proteins produced by infected cells to protect neighboring cells and limit the spread of the virus in the body. Without interferons, herpes can spread to the brain, where the immune mechanisms are restricted.