Tony Du is a first-generation Chinese American epidemiologist living in Maryland who has closely followed COVID-19 and its path of destruction since its very beginning in Wuhan. Now that it's hitting the U.S. hard, he's doing what he can to help out locally.

A couple of weekends ago, he spent some of his down time training to join the Maryland Responds Medical Reserve Corps, a community, volunteer group that bolsters the U.S. public health system.

Later that week, U.S. President Donald Trump used the term "Chinese virus" publicly for the first time. Du was floored.

"This is the darkest day I have seen in my 20 years in the United States," he posted on the Nextdoor app he sometimes uses to volunteer help to neighbours in need.

In an interview this week with CBC News, he elaborated.

"I think that is very, very wrong," he said of Trump's choice of words. "Here I am preparing to fight for our public, and you stab me in the back."

Liang Zhao, Rose Xu, Angela Men and Tony Du collect personal protective equipment for local health care workers in Maryland. (Jun Tong)

Du said his son's classmates now sometimes say they want to stay away from the Asian kids in school because they might have the virus.

"I don't want anyone to call my kid 'coronavirus,'" Du said.

'Kung Flu'

A Washington Post photographer captured a shot of Trump's briefing notes from March 19, which showed "corona" struck out in black marker before the word "virus" and replaced with "Chinese."

Since then, Trump has repeatedly called it the "Chinese virus" while other world leaders stick with calling it COVID-19 or the novel coronavirus.

A close-up of U.S. President Donald Trump's notes for the March 19 coronavirus briefing shows where the word 'corona' was crossed out before the word 'virus' and replaced with 'Chinese.' (Jabin Botsford/The Washington Post/Getty Images)

Last week, CBS White House correspondent Weijia Jiang said a White House staffer called the virus the "Kung Flu" when talking with the reporter.

The comment "makes me wonder what they are calling it behind my back," Jiang posted on Twitter.

This morning a White House official referred to <a href="https://twitter.com/hashtag/Coronavirus?src=hash&ref_src=twsrc%5Etfw">#Coronavirus</a> as the “Kung-Flu” to my face. Makes me wonder what they’re calling it behind my back. —@weijia

On Wednesday, U.S. Secretary of State Mike Pompeo, in a meeting with his G7 colleagues, insisted the virus be called the "Wuhan virus" in a joint communique. Ministers from other countries refused to agree.

The problem with naming the virus this way, the World Health Organization points out in guidelines, is that disease names really do matter. History has shown that certain names have caused a backlash against particular groups.

Trump has since tried to walk back his comments, calling Asian Americans "amazing people" in a March 23 tweet.

"The spreading of the Virus is NOT their fault," he wrote.

It is very important that we totally protect our Asian American community in the United States, and all around the world. They are amazing people, and the spreading of the Virus.... —@realDonaldTrump

But a half-hour drive north of Washington — back in Maryland — Asian Americans are worried.

Du and his Chinese American friends and colleagues say they are experiencing daily micro-aggressions and blatant racism.

One friend monitors WeChat groups reporting verbal and physical assaults. Another, Liang Zhao, said his son was out walking the dog when a woman walking in the opposite direction asked him to stop and switch to the other side of the road.

"Your dog looks beautiful, but you know," said Zhao, describing what the woman told his son.

Ironically, Zhao, Du and several other Chinese Americans have raised $80,000 in a GoFund me campaign to help provide personal protective equipment to front-line health care providers in the region.

Watch: How to confront racism sparked by coronavirus fears

Despite the low risk of transmission in this country, Asian Canadians have become the targets of xenophobic comments in recent days, both online and offline. 3:38

'Please stop the prejudice'

Aryani Ong is a former civil rights attorney who has specialized in Asian American rights for the last 30 years. She's an Indonesian Chinese American based in Maryland and says that what's happening in her home state with Chinese-Americans is rippling out across the U.S.

She points to big numbers of racist incidents reported on NextShark, an Asian American news site, and on the Asian Pacific Policy and Planning Council site.

"These kinds of numbers are not something I have seen before," said Ong.

Aryani Ong is an Indonesian-Chinese-American civil rights attorney living in Bethesda, Md. She says Trump 'lacked the sensitivity' to understand the impact of his words on Asian Americans. (Aryani Ong)

The incidents are higher in some U.S. cities with large Asian American populations, such as New York City, Los Angeles and San Francisco.

That's why Asian American Hollywood actors and political leaders, including California Governor Gavin Newsom and Democratic Rep. Judy Chu, are speaking out against racism.

Martin Luther King Jr.'s daughter, Bernice King, recently tweeted: "Please stop the prejudice and senseless violence against Asian people. Randomly beating elderly, sometimes homeless Asian Americans is cowardly, heartbreaking and it's inexcusable."

U.S. President Donald Trump tried to walk back his earlier references to the 'Chinese virus' by calling Asian Americans 'amazing people' and calling for them to be protected. (Alex Brandon/The Associated Press)

"Trump wants the news to focus on the foreignness of the disease, but in doing that, he lacked the sensitivity to understand the impact on the Asian Americans," said Ong.

"He should have been cognizant of the impact on Asian Americans. The general public does not differentiate well. And now, we see people are accosting Asian Americans as being disease carriers."

'More afraid of crazy people than the virus'

That's exactly what sent Jonathan Yeung, a father of two young children, to the Engage Armament gun shop in Rockville, Md., this week.

"Luckily, this city is still very peaceful, I have not experienced it, knock on wood," said Yeung, after purchasing his first gun.

"I don't want to experience it. I blame our president. The word that he's chosen is really damaging and hurting the Asian community. It's not necessary to call it the Chinese virus."

WATCH | Jonathan Yeung explains why the recently bought a gun:

Maryland resident Jonathan Yeung explains why the coronavirus pandemic has prompted him to buy his first gun. He says U.S. President Donald Trump's use of the term 'Chinese virus' has potentially put Asian Americans in danger. 0:52

Andy Raymond is the co-owner of Engage Armament and said he's seen a 300 per cent uptick in gun sales since the outbreak of COVID-19 and that many of the buyers are Asian American.

"They're afraid of the consequences of what this virus will bring," he said. "They're just afraid — whether it's to protect their families or from backlash against anti-Chinese sentiment or for some kind of lockdown."

Andy Raymond co-owns Engage Armament in Rockville, Md., and said he’s seen a 300 per cent uptick in gun sales since the outbreak of COVID-19. Many of the buyers are Asian American, he said. (Paul Andre St-Onge Fleurant/CBC News)

Du, too, has been motivated to buy a gun recently. He already owns one but said he's now in the process of getting an AR-15-style semi-automatic weapon.

"I am more afraid of crazy people than the virus," said Du.