Common viral infections can cause Alzheimer’s disease, new research shows, raising hopes that a cheap, widely available drug could prevent deadly diseases

A ‘harmless’ virus carried by half of all adults could increase the risk of Alzheimer’s disease, shock research suggests today.

Cytomegalovirus (CMV), which causes a common cold, can be spread from person to person through body fluids such as blood, saliva and urine in the same way as other viruses.

But the infection is present in up to 45 percent of Alzheimer’s cases, US scientists claim.

Some people exposed to the bug may develop a chronic intestinal infection, which can cause it to enter the bloodstream and travel to the brain.

Here it is recognized by the brain’s immune cells – microglia – say the researchers, contributing to the biological changes involved in Alzheimer’s disease.

The scientists, who called the findings “exciting,” hope the research can pave the way to confirming whether common antiviral medications used to treat CVM can help prevent this form of the memory-robbing disease.

However, they warned that simply coming into contact with the virus – which happens to almost everyone – should not be a cause for concern.

The infection does not appear to be associated with Alzheimer’s disease until it is found in the brain.

Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss

To date, neither disease has yet been consistently associated with the disease.

Dr. Ben Readhead, co-author of the study and associate professor of neurodegenerative diseases at Arizona State University, said: ‘We think we have found a biologically unique subtype of Alzheimer’s disease that can affect 25 to 45 percent of people with this disease. meet.’

This subtype, he added, shows a buildup of the proteins amyloid and tau in the brain – a hallmark of Alzheimer’s disease – as well as a “distinct profile of (the CVM) virus, antibodies and immune cells in the brain.”

‘This subtype of Alzheimer’s disease includes the characteristic amyloid plaques and tau tangles – microscopic brain abnormalities used for diagnosis – and shows a distinct biological profile of viruses, antibodies and immune cells in the brain.’

In the study, the scientists examined spinal fluid to track how CVM antibodies move around the body.

They found CMV in the vagus nerve, which carries signals between the brain, heart and digestive system, and suggested that this was how the virus travels to the brain.

Tests on human brain cells subsequently revealed the virus increased the production of amyloid and tau proteins and contributed to the degeneration and death of neurons.

The researchers write in the journal Alzheimer’s and Dementia that the study illustrates the impact that infections can have on brain health and neurodegeneration in general.

Around 900,000 Britons are currently thought to suffer from memory theft disorder. But scientists at University College London estimate that this number will rise to 1.7 million within 20 years as people live longer. It represents an increase of 40 percent compared to the previous forecast in 2017

But further independent studies are needed to test their findings and resulting hypotheses, she added.

Dr. Eric Reiman, executive director of Banner Alzheimer’s Institute and senior author of the study, also said, “We are excited about the opportunity to have researchers test our findings in ways that will make a difference in research, subtyping, treatment and prevention of Alzheimer’s disease. .’

Recent analysis by the Alzheimer’s Society estimates that the total annual cost of dementia to Britain is £42 billion per year, with families bearing the brunt.

An aging population means these costs – including the lost income of unpaid caregivers – are expected to rise to £90 billion over the next fifteen years.

It is thought that around 944,000 people in Britain are living with dementia, while in the US the figure is around 7 million.

Alzheimer’s disease affects about six in ten people with dementia.

It is thought to be caused by a buildup of amyloid and tau in the brain, which clump together, and by plaques and tangles that make it harder for the brain to work properly.

Eventually, the brain struggles to cope with this damage and dementia symptoms develop.

Memory problems, thinking and reasoning problems, and language problems are common early symptoms of the condition, which then worsen over time.

Dementia is expected to explode in the coming years, making a low-cost screening tool crucial to meet the challenge.

The analysis by Alzheimer’s Research UK found that 74,261 people died from dementia in 2022, up from 69,178 a year earlier, making it the country’s biggest killer.