Nicole Loher felt the symptoms come on all at once. She had a cough, body aches and due to an exercise heart monitor she wears on her wrist, could even see that her heart rate was elevated.

The 26-year-old New Yorker had also been in contact with someone who suspected they had contracted the coronavirus, so she did what all the health experts have advised and called the specialised emergency advice number.

But that call sent her down a bureaucratic dead end that many sick Americans have experienced in the past week as they try and fail to seek testing from their medical providers.

“I was on the phone for 30 minutes with a woman who was reading off a prompt,” she told The Independent of the call she made on Wednesday.

Her call was transferred to her local hospital board, who were unsure why she was transferred there. Confusion followed.

“They went on a hunt to find someone who could help me. Turns out they only had two nurses on staff that are helping patients evaluate their symptoms on the phone,” she said.

Three days later, her symptoms have not subsided, and she is still waiting for a call back.

Cases like Ms Lohr’s have raised concerns that many cities across the US are not adequately dealing with the coronavirus pandemic, and that the true number of cases may be significantly higher than officials are admitting.

The US Centers for Disease Control and Prevention (CDC) has reported 1,678 cases of the coronavirus, an increase of 414 cases from its previous count, and said that the number of deaths had risen by 5 to 41.

“I kind of just went into pure shock,” Ms Lohr said after her failed attempts to get medical attention. “I was taking stock of what I have and trying to mentally figure out what I may need help with.”

The difficulty of getting tests is fast becoming one of the weakest links in the chain of the US government’s response to the crisis.

The Trump administration has sent conflicting signals about who is able to receive tests for the virus. Donald Trump said last week that “anyone who wants a test can get a test” — but that has not been the experience for many.

Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, told a congressional committee on Thursday that the lack of testing was “a failing.”

“The idea of anybody getting it easily the way people in other countries are doing it, we are not set up for that. Do I think we should be? Yes. But we are not,” he added.

Experts have said the high frequency of testing by Chinese authorities played a key role in slowing its spread. In some of the worst-affected areas, people’s temperatures were monitored as they entered public spaces and sent for tests if it was elevated.

The White House has also appeared at times to downplay the importance of testing. A number of associates of the president have gone into quarantine after coming into contact with infected people, but Mr Trump has not yet been tested.

On Friday, Mr Trump appeared to blame his predecessor, Barack Obama, for the government’s difficulties in testing.

“For decades the @CDCgov looked at, and studied, its testing system, but did nothing about it. It would always be inadequate and slow for a large scale pandemic, but a pandemic would never happen, they hoped,” Mr Trump wrote on Twitter.

“President Obama made changes that only complicated things further. The changes have been made and testing will soon happen on a very large scale basis. All Red Tape has been cut, ready to go!” he added, without providing any evidence for the claim.

Meanwhile, the restrictions in testing in the US appear to be affecting even those who have travelled to countries with high rates of infection.

Michael Page, a 37-year-old NGO manager, returned from a work trip to Paris earlier this month with a cough. He contacted his physician to outline the symptoms and was brought in for a brief checkup.

“They checked my lungs, ear nose and throat. But there wasn’t even a question of getting tested for coronavirus,” he said. “It wasn’t even brought up because there is absolutely no availability.”

“‘Not only that, there is no follow up,” he added. "I’ve been practicing social distancing but I can't test one way or another. You essentially can’t get the test until you are at death's door.”