A new study conducted by the Johns Hopkins Medical School and the University of Nebraska has found a virus, previously thought to live only in freshwater algae, that makes people “dumber” by infecting their brains. The study was publishedin the Proceedings of the National Academy of Sciences (PNAS) journal in October.
The virus -called chlorovirus ATCV-1 -was found in the throats of healthy people. The scientists were conducting a completely unrelated study when they found that the DNA of the chlorovirus Acanthocystis turfacea chlorella virus 1 (ATCV-1) matched with the DNA in the throats of healthy people.
According to the scientists involved up to half of the human race could be infected with this virus, which means that millions of people may be carrying a constant infection which dulls the brain.
William Allington Distinguished Professor of Plant Pathology and a co-director of the Nebraska Center for Virology at UNL, Dr. James Van Etten said:
“There’s more and more studies showing that microorganisms in your body have a bigger influence than anything anyone would have predicted, and this could be something along those lines.”
He also noted:
“Chloroviruses are worldwide. They’re very common among inland bodies of fresh water such as lakes and ponds. But I don’t know of many examples of viruses jumping from one kingdom to another. If this turns out to be true, this is quite rare and a total surprise.”
The scientists also estimated that the throat virus could be living in large segments of the population, because about 44% of patients tested in the study were infected. Moreover, the algae virus, never before observed in healthy people, was found to affect cognitive functions including visual processing and spatial awareness. Those infected performed 10% worse in tests requiring visual processing.
Mary-Ann Russon wrote in IB Times:
“For the first time ever, the researchers proved that microorganisms have the ability to trigger delicate physiological changes to the human body, without launching a full-blown attack on the human immune system. However, the scientists do not yet know how ATCV-1 infects a human host and it’s not as simple as just going swimming in a lake or pond, so there’s no need to stop doing that yet.”
The virologist who led the original study, Dr Robert Yolken, of Johns Hopkins medical school reportedly explained in the UNL press-release:
“This is a striking example showing that the ‘innocuous’ microorganisms we carry can affect behaviour and cognition. 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 harbour and the way they interact with our genes.”
He also told the Healthline:
“We’re really just starting to find out what some of these agents that we’re carrying around might actually do. It’s the beginning, I think, of another way of looking at infectious agents — not agents that come in and do a lot of damage and then leave, like Ebola virus or influenza virus.
This is kind of the other end of the spectrum. These are agents that we carry around for a long time and that may have subtle effects on our cognition and behaviour.”
It’s still unclear how ATCV-1 comes to infect humans, but animals infected with the virus showed similar difficulties.
The researchers confirmed their study by performing tests on mice. After injecting the virus into mice, they found that mice had a decrease in recognition memory and other brain functions.
The co-investigator Mikhail Pletnikov, MD, PhD, director of the Behavioral Neurobiology and Neuroimmunology Laboratory at Johns Hopkins said:
“The similarity of our findings in mice and humans underscores the common mechanisms that many microbes use to affect cognitive function in both animals and people.”
Actually, the human body contains trillions of bacteria and viruses most of which are inoffensive. But according to this study, some of these viruses can have a damaging effect on cognitive functions, while leaving individuals otherwise healthy.