Daily Dose: Vaccine-preventable Viruses & Neurodegenerative Disease

Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.

On February 17, 2023, we reported on a study published in the journal Neuron that examined potential links between viral exposures and neurodegenerative disease risk.

The study

Researchers queried resources from the FinnGen project and the UK Biobank (UKB) to mine potential associations between viral exposures and a variety of common neurodegenerative diseases, including Alzheimer disease (AD), amyotrophic lateral sclerosis (ALS), generalized dementia, vascular dementia, Parkinson disease, and multiple sclerosis (MS). Researchers found 45 signficant associations in the longitudinal data from FinnGen between exposure to a viral infection and subsequent risk of developing a NDD; 22 of these associations were replicated in the cross-sectional data from participants aged ≥60 years obtained from the UKB.

They found that dementia was the neurodegenerative disease associated with the greatest number of virus exposures, linked to 6: influenza, influenza with pneumonia, viral pneumonia, viral encephalitis, viral warts, and other viral diseases.

The largest effect association observed was between viral encephalitis and AD. Investigators found 24 of the 406 (5.9%) cases of viral encephalitis went on to develop AD, higher than the general prevalence of AD (<3%) among individuals in the FinnGen control population.

Influenza (with or without pneumonia) was the most commonly associated viral endpoint, associated with all the neurodegenerative diseases studied except MS. Viral encephalitis, intestinal infections, and varicella-zoster virus all were significant and replicated for more than a single NDD.

Note from authors

"In light of the current coronavirus pandemic, our results illustrate the need to take seriously the reports of concomitant neurological symptoms accompanying viral exposures and monitor at risk patients to discover if they will be at higher risk of NDDs in the future. The findings reported here cover multiple NDDs from two different biobanks, and previous research supports the described associations between viral infection and NDD risk, suggesting that virus/NDD associations are worthy of further investigation."

Click here for more details.