Zhang decries the fact that early on President Donald Trump made light of the seriousness of COVID-19, comparing it with the flu.

"It was highly misleading and has had a lasting impact on people's perception of the disease."

She also disagrees strongly with what she sees as the Trump administration and some state governments discouraging people from taking tests and seeking early treatment.

When Tian Liyan, 74, in New York on a visitor visa, called the public hotline on April 18 to inquire about tests, she was already one week into her sickness.

"I was told to stay at home as long as my condition was stable, since 'tests are performed only for people who are having severe symptoms like high fever or breathing difficulty and therefore have been admitted'," she says.

"Since I was in New York visiting my family I obviously needed to know whether I was infected so I went to Elmhurst Hospital. There were three doctors and only one patient, and anyone who wanted a test could get it right away."

Two days after her test, Tian felt that her condition had deteriorated, but not so much that she could be admitted to the hospital. Through a mutual friend, she called Zhang, who told her immediately to visit a nearby urgent care center, where she was X-rayed.

"The doctor told me there was no need to wait for the test result because the picture showed an opaque lung. … The test result came out three days later."

Jiang says that in the early days of the Wuhan outbreak, when test kits were scarce and results were not totally reliable, China's National Health Commission listed medical imaging as one of two methods (the other being the test) that could lead to a positive diagnosis and therefore ensure being given a hospital bed.

This practice continued until the test was no longer a big issue in quantity and accuracy.

"In New York no machines are solely reserved for COVID-19 patients and the patients are not typically given a CT scan before they are admitted into the hospital," Jiang says.

"Do not test patients if your treatment plan is not going to change based on the test result" was the message from the CDC to US doctors, who, Zhang says, did not always see eye to eye.