A special pathogens expert praised the Centers for Disease Control and Prevention (CDC) Friday for what she sees as an expansion of coronavirus testing in the United States to allow clinicians to go beyond testing only those who recently traveled to China or who had been in close contact with someone who had traveled to that country.

Dr. Syra Madad, a special pathogens expert who serves as senior director of New York City’s System-wide Special Pathogens Program, told CNBC’s Squawk Box the United States must strengthen its coronavirus diagnostic capabilities.

“We’re glad that CDC has finally broadened their clinical case definition, so now clinicians can test people that they think have the coronavirus disease without a very narrow, you know, process in place,” Madad said, continuing:

We know that there are over, you know, three dozen countries reporting coronavirus disease, outside of China. And, in fact, if we look at it today there are more cases mounting outside of China than even inside of China. And so, you know, broadening the clinical case definition, it should have happened weeks ago, unfortunately, but we’re glad that it finally did happen.

Madad said it is unknown how many cases of the virus are circulating in the United States already.

“The first case in California was a wake-up call, something that we were expecting, but we don’t know how many more out there,” she explained. “So, we need to ramp up diagnostic capabilities.”

Madad said she is seeing an effort to build up preparedness for the coronavirus across the country:

China has given us this window of time, if you will. And, so, we need to make sure we’re using this window of time very effectively, everyone all healthcare systems need to look and brush up on their search management plans. They need to make sure they have good staffing … space, systems, processes in place to be able to care for patients that will present with coronavirus disease.

Madad, principal investigator with the Center for Global Healthcare Special Pathogens Preparedness, also appeared as herself in the Netflix documentary series Pandemic: How to Prevent an Outbreak.

At the end of January, Madad praised China for what she saw as its effort to attempt to slow the rapid spread of the new coronavirus.

“I think China is doing a great job,” she told Squawk Box. “Right now, the majority of cases are in mainland China and they’re doing a number of different public health measures.”

Asked about whether warmer Spring temperatures will bring down the numbers of people infected with the new coronavirus that causes the COVID-19 infection – similar to what occurs with flu – Madad suggested observing Singapore in answer to that question:

Singapore … if you look at the temperature there it’s almost summer, you know, and there are still cases that are coming up in Singapore, which shows that even with warm weather this virus may not actually go away. So, with seasonal flu, we know that it is more common during the winter months during the cold time. It’s actually around all year long … But, I think in Singapore you’re seeing there are cases still arising, so we can’t really tell, but I think Singapore is a country we should continue to look at.

Madad said while it is important to observe the coronavirus “to get the full picture in order to understand what we’re dealing with,” at the same time, she warns that time is precious.

“The more you wait, the more human toll is going to mount,” she explained. “And, so, we need to continue to look at public health measures and implement public health measures. At the same time, we need transparency in data to understand what is the severity.”