COVID-19 is too small to see with the naked eye, but the effects are all too obvious.
Fear of catching it is spurring countless people to wear masks and predominantly Asian areas like Los Angeles' Chinatown are being avoided.
"On Chinese New Year, which is usually our busiest day of the year, this year our attendance was probably down to a quarter of what it usually is," said Shirley Zhang with the Chinatown Business Improvement District.
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Lunchtime there has become relatively barren. But the number of coronavirus cases linked to Chinatown is zero.
"We've seen a downturn in business in places like Chinatown and there's really no good reason for that to happen," said Stewart Kwoh, who is with the group Asian Americans Advancing Justice.
He says misinformation is fueling not just unfounded fears, but aggression toward Asian Americans.
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His group's website is littered with examples. He said one case in the San Fernando Valley involved a middle school boy who had been bullied and physically attacked.
In another case, a woman in a face mask was allegedly assaulted by a man who called her "diseased."
Reports of bullying against Asian students have surfaced in some schools.
At the Torrance Unified School District, it hasn't been a problem, but the district says it's communicating with parents and looking out for students who may decide to wear face masks on campus.
"That sometimes is something that people will wear to school and they feel comfortable doing that and we want to make sure that they feel safe," said Tammy Khan with the Torrance Unified School District. "And really our priority is making sure our school communities are healthy and safe."