A Phoenix mom panicked when her baby got coronavirus, but some strains are common

Corrections & Clarifications: A previous version of this article incorrectly identified the genetic material of the virus that is being studied.

A virus once concentrated in China is now spreading globally, and a Valley mother said she thought her daughter could be the second confirmed case in the United States, but Phoenix hospital officials say her baby actually has a common and less harmful strain of the virus.

There are many different strains of coronavirus common throughout the world that cause infections in insects and animals, but only seven strains that cause infections in humans. Of those seven strains found in humans, four are extremely common, according to Brenda Hogue, an Arizona State University researcher who specializes in studying the coronavirus.

"They do cause what we recognize as the common cold," Hogue said. "So it's just an upper respiratory type infection."

About 30% of common colds are caused by a strain of coronavirus, Hogue said. However, the other three strains that affect humans are much more severe, including a new strain that was first identified in Wuhan, China, late last year.

This novel strain of coronavirus has caused illness in hundreds of people and killed at least six. But Phoenix Children's Hospital has not treated any cases, officials confirmed Wednesday.

Valley baby developed fever, cough

Brittany Swain, 28, of Phoenix, said her 1-year-old daughter, Kylie, was in Phoenix Children's Hospital this week with a strain of coronavirus. 

According to Swain, Kylie was always a "healthy baby" until Friday when she developed a fever and cough. By Saturday evening, she was "breathing rapidly," and on Sunday, Swain decided to take her to the hospital.

When doctors began checking Kylie's vitals, Swain said they raised serious concerns among staff.

"I knew it was serious when I saw all of these doctors coming into our room," said Swain. "I had no idea about the coronavirus at the time, but they told me they were certain that was what this was." 

The most common signs of infection include fever, cough, shortness of breath and breathing difficulties — symptoms that align closely with Kylie's. However, many of these symptoms are common among all strains of coronavirus, not just the novel strain from China.

The biggest difference between the new strain of coronavirus and more common strains is that the new one causes lower respiratory infections akin to severe pneumonia, whereas more common strains only cause upper respiratory infections.

Swain said the hospital released Kylie on Wednesday.

"I am relieved that it is not the one from China," she said. "Today, she is a lot better."

Phoenix Children's Hospital treats 'many' coronavirus patients every year

Phoenix Children’s Hospital's Chief Medical Officer Dr. Michael Ritchey confirmed in a statement Wednesday that the baby has coronavirus but that it is not the new strain of coronavirus that has killed six people in China.

"There are many strains of coronavirus, which can produce illness ranging mild to severe in nature. Phoenix Children’s clinical team treats many patients each year with coronavirus, but Phoenix Children’s has yet to treat a patient with the novel coronavirus strain from China," he said.

The baby's case "is not severe, nor is it related to the virus from China," he said. 

The first case in the U.S. was announced on Jan. 21 involving a Washington state man in his 30s who had been traveling in China and visited Wuhan. The man is in good condition at a local hospital, the Centers for Disease Control and Prevention said.

There are ongoing investigations to learn more. No other cases have been confirmed in the U.S.

What to know about coronavirus

The virus can be spread from animals to people. But it also can be spread by coughing, sneezing and through close contact with an infected person or an object carrying the virus.

Based on what she knows so far from a genetic analysis of the new virus, Hogue said the virus seems to be most similar to another severe strain of coronavirus that first appeared in 2003 called severe acute respiratory syndrome, also known as SARS, as well as one strain of coronavirus that is found in bats.

"But it's not clear that it's spreading as quickly as SARS," she said. "We need to get more information on patients who have been infected."

Hogue previously worked on developing a vaccine for SARS that worked to generate antibodies in mice, but that was never developed for human use.

"By then, SARS was contained," she said.

Developing vaccines for human use can be costly, and getting Food and Drug Administration approval can take time, but Hogue said she is open to using her  research to help potentially develop a vaccine for this new strain of coronavirus.

She is studying the new virus's RNA  and said the vaccine she worked on for SARS wouldn't necessarily work for the new strain — which has clear genetic differences — and would need tweaking.

"This new virus, when you compare with other coronaviruses, is really a novel virus," she said.

While she can see clear genetic differences in the RNA , she said researchers will need time to fully understand what the results of those differences are and how the virus works.

USA TODAY reporter John Bacon contributed to this article.