Coronavirus Update: Two-thirds of seriously ill COVID-19 patients didn't have fever, study finds

A new study is presenting surprising findings about COVID-19 and which factors play the biggest role in how severe the disease is for some people.

With New York being the epicenter for the virus in the U.S., researchers from the state's largest health care system moved quickly to document findings that would help others identify and treat COVID-19 patients. One thing stood out in the study published in the Journal of the American Medical Association.

"The most surprising finding to me was that two-thirds of the patients who were seriously ill with an active infection did not have a fever," said senior researcher Karina Davidson, PhD.

Fever is the first symptom doctors look for, but Davidson said the sickest patients didn't present with a fever.

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"This is a puzzling infection," she said. "Different people have different symptoms, some of them mild, some of those severe."

While having asthma is a major concern, researchers found the virus tends to target those with other common conditions.

Davidson and her colleagues from Northwell Health's Feinstein Institutes for Medical Research looked at the records of 5,700 hospitalized COVID-19 patients between March 1 and April 4.

Fifty-seven percent had hypertension (high blood pressure), 41% were obese and 34% had type 2 diabetes. The results reveal COVID-19 is much more than just a lung disease.

"It is going to have not just short-term effects that are deleterious on many target organs, but we may be looking at an infection that has long-term consequences," Davidson said.

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Men were more likely than women to die in every age group. And patients with diabetes were more likely to end up with acute kidney disease and on a ventilator.

Recent numbers from the Centers for Disease Control and Prevention show 1 out of 3 Americans have high blood pressure, 40% are obese, and more than 10% have type 2 diabetes. Researchers say their findings are a call to action.

"We have many chronic disease conditions for which prevention and management exists," Davidson said. "We have a duty to make sure that everyone gets that."

The hope is that these findings will help doctors evolve the way they treat patients.