|The patient's initial swabs tested negative for the coronavirus. Photo: AFP|
In a study published in the medical journal The Lancet on Monday, the doctors said scans of the patient's lungs indicated a fungal invasion, tests showed no telltale sign of the coronavirus in the upper respiratory tract and the patient had an immune response called a cytokine storm within just hours of the disease's onset.
"For a disease that was unknown only five months ago, it might … be too early for clinicians to be certain of which manifestations are typical," the team led by Timothy Harkin from Mount Sinai Hospital's pulmonary division, said in the paper.
The patient was a 34-year-old male anaesthesiologist in otherwise good health. He initially tested positive for influenza A and the symptoms disappeared following a routine treatment.
After more than 10 days' rest, the patient returned to work at a medical centre in the city only to suddenly fall very ill that afternoon and be admitted to the emergency department at Mount Sinai Hospital.
The symptoms included fever, chills and shortness of breath. The patient also developed a cytokine storm, a life-threatening condition in which the immune system attacks healthy cells.
Harkin said a nasal sample from the patient came back negative for Covid-19.
The patient's symptoms quickly improved after he was given some antibiotics and other standard treatment for a lung infection. But on the fifth day the patient's condition worsened again.
"[Medication was] administered, without clinical improvement," the paper said.
The man's lung scan showed a halo-like sign of inflammation in the right lung, which radiologists suggested could be a fungal infection.
"[The inflammation] was not characteristic of previously reported CT findings for Covid-19," the paper said.
However, the team suspected that the patient might have Covid-19 and the man was tested for the coronavirus again on the seventh day. These tests also returned negative results.
The Mount Sinai team decided to get a sample using a method known as bronchoalveolar lavage (BAL).
BAL involves inserting a tube in a patient's lung to extract fluids and tissues. It is expensive, time-consuming and uncomfortable, and is not widely used in the United States, with the American Association for Bronchology and Interventional Pulmonology opposing its use in Covid-19 testing in all but extreme cases.
But researchers in China have said that the approach can increase the accuracy of viral detection to more than 90 per cent ― compared with about 60 per cent for nasal swabs and 30 per cent for oral swabs.
The New York patient's BAL test was positive. By the time the patient learned that he had Covid-19, he had already spent nine days in hospital. He was still sick, but his condition had stabilised.
"Via follow-up phone calls, the patient reported that his cough and myalgias slowly resolved, and he had no fever higher than 37.8 degrees Celsius," the researchers wrote.
The doctors were struck by several unusual presentations in the patient's symptoms. He developed a cytokine storm within a few hours of the disease's onset, something that rarely happens so quickly.
The doctors were also puzzled by the absence of virus in the upper respiratory samples even at the peak of infection, adding that this could be the result of a previous medication. The patient had been taking drugs on a regular basis for pre-exposure prevention of HIV, an occupational hazard for doctors in New York.
The case adds to the mysteries about the novel coronavirus. Some patients in China, for example, tested negative to an oral swab but positive in anal samples. Scientists also found viral strains hidden deep inside the lung of a patient who had recovered.
Some researchers say that the questions are the result of an inadequate understanding of the interaction between the new virus and our immune system, while others suspect that the virus might have mutated and those new strains are causing symptoms different from those reported in earlier cases.