Epstein-Barr Virus Infection Linked to Tripled MS Risk

New study finds mono caused by the herpes virus may increase likelihood of developing multiple sclerosis.

Apr. 15, 2026 at 7:00pm

Got story updates? Submit your updates here. ›

A translucent, ghostly X-ray photograph showing the detailed internal structure of the Epstein-Barr virus, conceptually illustrating the clinical connection between this virus and the increased risk of developing multiple sclerosis.An X-ray-like image reveals the intricate inner workings of the Epstein-Barr virus, which may hold clues to its link with the development of multiple sclerosis.Rochester Today

A new study published in Neurology Open Access has found that an Epstein-Barr virus infection resulting in infectious mononucleosis, or mono, appears to triple the risk of developing multiple sclerosis (MS) later in life. Researchers analyzed over two decades of health records and found that people who had mono were about three times more likely to develop MS compared to those who never had the illness.

Why it matters

Multiple sclerosis is a relatively rare but serious degenerative brain disease that can lead to significant disability. Understanding potential risk factors like Epstein-Barr virus and mono could help researchers develop strategies to prevent MS and reduce its overall burden on public health.

The details

The study, led by epidemiologist Jennifer St. Sauver of the Mayo Clinic in Rochester, Minnesota, looked at data on 4,721 patients who had tested positive for Epstein-Barr virus and infectious mononucleosis. This group was compared to 14,163 people of the same age and sex who never had mono. Over an average follow-up period of 8 years, 8 people (0.17%) who had mono went on to develop MS, compared to 10 people (0.07%) in the control group.

  • The study analyzed health records spanning more than 20 years.
  • The findings were recently published in the journal Neurology Open Access on April 1, 2026.

The players

Jennifer St. Sauver

An epidemiologist at the Mayo Clinic in Rochester, Minnesota and the lead researcher on the study.

Epstein-Barr virus

A herpes virus that is the most common cause of infectious mononucleosis, or mono.

Multiple sclerosis (MS)

A rare but serious degenerative brain disease that can lead to significant disability.

Got photos? Submit your photos here. ›

What they’re saying

“These results highlight the need for further research into ways to prevent infection with the Epstein-Barr virus. Preventing these infections could reduce the overall burden of MS.”

— Jennifer St. Sauver, Epidemiologist, Mayo Clinic

“Mononucleosis is a relatively uncommon illness, but developing strategies to prevent infection with the virus that causes this disease could help us to lower the number of MS cases in the future.”

— Jennifer St. Sauver, Epidemiologist, Mayo Clinic

What’s next

Researchers plan to continue investigating the potential causal link between Epstein-Barr virus, mono, and multiple sclerosis in order to develop prevention strategies.

The takeaway

This study adds to the growing body of evidence linking Epstein-Barr virus and the development of multiple sclerosis, a debilitating neurological condition. Understanding and preventing Epstein-Barr infections could be an important step in reducing the overall burden of MS on public health.