Maybe one day there could be a cure for stupidity after all. A new study of a virus commonly found in algae reveals cognitive function suffers modest reductions when the virus is present in humans.

The research team from Johns Hopkins University and the University of Nebraska didn’t set out to measure the virus’s deleterious effects. But like a lot of great scientific insight, when a more groundbreaking pattern emerged, the researchers pursued it. To their mind, this is the first documented case of a potentially harmful algal virus crossing over to infect healthy people.

During a separate look into throat microbes, the team discovered DNA from the chlorovirus ATCV-1, a type of algal virus, was present in 40 of the 92 subjects. While this virus is common among aquatic environments, it’s rarely found in humans. So the team changed directions. They relied on prior tests of visual processing and motor function to see how the virus might affect these processes.

“This is a striking example showing that the ‘innocuous’ microorganisms we carry can affect behavior and cognition,” lead author and neurovirologist at Johns Hopkins, Dr. Robert Yolken, told The Independent.

Study participants were given the task of drawing a line between a sequence of numbers. Those who had ATCV-1 in their systems showed significantly slower performance, by about 10 percent, compared to those without the virus’s DNA. Yolken and his team found no differences with respect to sex, race, income, education level, or smoking habits.

Wanting to delve deeper, the team infected a set of lab mice with the virus and left another group untouched. Infected mice completed a maze 10 percent slower and spent 20 percent less time exploring new objects than uninfected mice. The virus appeared to deplete functions related to “learning, memory formation, and the immune response to viral exposure,” the team wrote.

For all these confirmations of the virus’s capabilities, senior author of the study Dr. James L. Van Etten says the findings should come with no alarm. “Since these viruses are ubiquitous in nature, at this point I would tell people not to worry about them,” he told Medical Daily.

They are not, for instance, the same as the toxoplasmosis-causing parasite known as Toxoplasma gondii, which infects house cats and may transfer to humans. T. gondii can live in warm-blood animals but only reproduce in felines. Van Etten says he isn’t sure whether the same holds true for ATCV-1. The exact mechanisms behind the effects are also unknown, though he concedes the data should be forthcoming. “Currently one of our efforts is to determine if the virus can replicate in either human or animal cells.”

If the virus can replicate, that means it can spread between people. But without that information, people should find comfort in the virus only being tested in the Baltimore area in a relatively small pool of subjects. While it may use other microorganisms to get into people’s throats, algae are everywhere. And if nothing else, a 10 percent reduction isn’t all that much — hardly different than skipping your morning cup of coffee.

Source: Yolken R, Jones-Brando L, Dunigan D, et al. Chlorovirus ATCV-1 is part of the human oropharyngeal virome and is associated with changes in cognitive functions in humans and mice. PNAS. 2014.

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