Researchers from Johns Hopkins University and the University of Nebraska joined a collaborative study on a virus that is commonly found in algae. According to Medical Daily, the scientists didn't originally begin their study with the goal of testing the chlorovirus ATCV-1.
However, over the course of the study, the researchers noticed a "groundbreaking pattern" in the aquatic ecology of the algae and the manner in which the virus lives in humans. After encountering the virus by chance, the investigators decided it would be worthwhile to test the ways in which the microbes affect healthy humans. The study was published in the Proceedings of the National Academy of Sciences of the United States of America, and started a conversation within the medical community about how viral agents could alter cognitive ability. The virus that was investigated is commonly found in green algae, which lives in many streams, lakes and other waterways.
"The virus is commonly found in green algae, which lives in many waterways."
A virus that declines human mental capability
Scientists already know that bacteria has the ability to dramatically impact the body's natural evolutionary process. However, algal viruses influencing cognitive effects is largely unknown. However, human mucosal surfaces – such as those in the throat – contain a large number of microorganisms that can impact human health. As a result, the research team looked at 90 healthy subjects, and once they narrowed their focus on the chlorovirus, they discovered that 40 of the individuals were carrying it.
The more startling results were uncovered when investigators began tests that measured visual processing. After performing these cognitive assessments, researchers began noticing that those who carried the chlorovirus had lower performances. According to the International Business Times, assessments that tested human attention spans were also given. Those who tested positive for ATCV-1 scored seven to nine points lower than subjects who tested negative for the virus.
Scientists also conducted cognitive tests in mice, and discovered that when they put the animals in a maze, the ones with the chlorovirus had a more difficult time finding their way around compared to other mice who didn't carry ATCV-1 in their digestive tracts. This breakthrough discovery shows that even the most unobjectionable microbes can have long-lasting impacts on health – even without realizing it.
"This is a striking example showing that the 'innocuous' microorganisms we carry can affect behavior and cognition," lead investigator Dr. Robert Yolken, a virologist and pediatric infectious disease specialist at the Johns Hopkins Children's Center and director of the Stanley Neurovirology Laboratory at Johns Hopkins, explained to the International Business Times. "Many physiological differences between person A and person B are encoded in the set of genes each inherits from parents, yet some of these differences are fuelled by the various microorganisms we harbor and the way they interact with our genes."
Yolken and his team believe that their findings signal a major revelation in the way microbiomes, which are responsible for the levels of viral agents and bacteria in the body, affect human health. Future research that more closely examines microbiota could help investigators achieve greater insight into how viruses impact human cognition.
The impact of microorganisms in humans
What does this mean for future research? If the virus has the ability to replicate, this means that ATCV-1 has the ability to spread between humans. However, unlike more aggressive strains such as E.coli or the influenza virus, the chlorovirus in question should not raise any concern when it comes to infectious disease. Moreover, the testing related to the study was performed on a small cohort in Baltimore, so the wide-reaching impact of the findings is still largely unknown.
"Since these viruses are ubiquitous in nature, at this point I would tell people not to worry about them," senior author of the study Dr. James L. Van Etten explained to Medical Daily. "Currently one of our efforts is to determine if the virus can replicate in either human or animal cells."
The International Business Times also stated that so far, researchers still don't know how the virus made its way into human host, but it's likely that it wasn't "as simple as just going swimming in a lake or pond." However, given the fact that this algae lives in aquatic habitats, water quality likely plays a factor in the viral spread.
Have scientists discovered a virus that weakens the brain?
Many headlines related to this study, which was published in late 2014, claimed that researchers found a virus that influences physiological changes to the human body without creating a severe strain on a person's well-being. Unlike the flu virus, for example, the physiological impact of chlorovirus doesn't actually make people sick, but rather impairs their cognitive ability in a delicate and slow-moving manner. Because the results were similar in animals and humans, there will likely be future research conducted to show how these microbial agents move throughout the human body.