Chronic Viral Infections Linked to Cognitive Decline Among Older Adults

A new study published in the journal Alzheimer's Disease and Associated Disorders  suggested that certain chronic viral infections could contribute to the cognitive deterioration of adults.

One should take infections seriously because viral infections have the potential to cause a decline in one's mental abilities among healthy older adults. Common colds, for instance, are a frequent occuring viral infection. Flu, chickenpox and herpes are another viral infections.

There have been several cross-sectional studies suggesting a link between exposure to cytomegalovirus (CMV), herpes simplex viruses (HSV) 1 and 2, protozoa Toxoplasma gondii and a decreased in cognitive functioning, said lead investigator Vishwajit Nimgaonkar, M.D., professor of psychiatry, Pittsburgh School of Medicine.

"Our study is one of the few to assess viral exposure and cognitive functioning measures over a period of time in a group of older adults," Nimgaonkar said. "It's possible that these viruses, which can linger in the body long after acute infection, are triggering some neurotoxic effects."

Per EurekAlert! The team looked for signs of viral exposure in the blood sample collected during the "Monongahela-Youghiogheny Healthy Aging Team" (MYHAT) study.

In the said study, there were over 1,000 participants, aging 65 years and older. They evaluated them every year for five years to investigate cognitive change over time.

The researchers learned that exposure to CMV, HSV-2 or toxoplasma is associated with a different aspect of mental deterioration in older people. This could possibly explain why the condition is considered as age-related decline.

"This is important from a public health perspective, as these infections are very common and several options for prevention and treatment are available," said senior investigator Mary Ganguli, M.D., M.P.H., professor of psychiatry at Pittsburgh, Science Newsline Medicine reported. "As we learn more about the role that infectious agents play in the brain, we might develop new prevention strategies for cognitive impairment."

Live Science reported another study two years ago about chronic infection leading to memory problems later in life. According to the report, the more chronic infection patient experienced, the worse he or she performed during various cognitive tests.

Dr. Daniel Lackland, a professor of epidemiology at the Medical University of South Carolina, described the old study as a solid proof that "makes sense from a biological viewpoint." It somewhat proves what many have suggested about infections and the brain. Lackland was not involved in the study.

The researchers of the new study are now investigating the subgroups of people to determine whose brains are more vulnerable to the effects of chronic viral infection.