There are now three confirmed cases of the new coronavirus in Collin County, health officials confirmed Tuesday.

The updated number includes the original case of a Frisco man, his wife and their 3-year-old child, Collin County Judge Chris Hill said. Test results for two other children in the family came back negative.

A retest of a fourth child came back Wednesday as negative for COVID-19, county officials said.

The man had been in the Silicon Valley area last week on a business trip and presumably had come into contact with someone carrying the COVID-19 virus, Hill said in a Monday news conference. The man noticed he was feeling ill after arriving home and was not contagious while on the airplane.

There are now three confirmed cases of the new coronavirus in Collin County, health officials confirmed Tuesday.

Hill says the man returned at the end of February and began experiencing symptoms the last day of February and the first days of March.

“He got back and developed a cough and other flu-like symptoms. Did exactly what we would coach our citizens across the county to do: talked to his doctor, got tested for the flu, got tested for Coronavirus and once it was confirmed took immediate steps to isolate himself,” Hill said.

Tests done by the Collin County Health Department confirmed the man contracted COVID-19, so did his wife and their three-year-old child.

The three patients are self-quarantined at home with mild symptoms, Hill said.

There are now three confirmed cases of the new coronavirus in Collin County, health officials confirmed Tuesday.

The man’s three other children were also tested, as was a family friend.

The friend and two children’s tests all came back negative.

However, a third child who attends Tadlock Elementary School received an "inconclusive" result and is being tested again.

Results for the child’s test should be in the next 48 hours, according to Hill, who stresses even if the test comes back "positive" the child in question stayed home when they would’ve been contagious.

Hill is not releasing information as far as what locations the man visited before being diagnosed.

“I don’t know that we have information that is helpful to the community about where he’s been,” Hill said.

But the judge does say the family did not attend mass gatherings recently and had contact with 17 to 20 people, mostly the man’s family and some of his co-workers at an undisclosed location.

Those co-workers have been contacted and advised to monitor their health for two weeks.

“There’s no reason for anyone to go beyond a heightened sense of awareness, to heightened sense of panic,” said Hill. “We don’t need that. It’s not helpful. Those who came into contact with this individual have already been contacted. They’re monitoring their health right now. If there’s something else to report we certainly will.”

Frisco ISD on Monday confirmed one of the children in the family attends Tadlock Elementary School. On Tuesday, health officials confirmed the child who tested positive was not school-aged and did not attend daycare.

The family's two school-age children did not have symptoms and were not contagious when they were at school.

Frisco ISD is currently on spring break.

Health officials on Monday tested a seventh person who came into contact with the family soon after the father reported he had tested presumptive positive for COVID-19. The individual is now under self-quarantine.



Meanwhile, two major sporting events in Frisco are moving forward.



Beginning Wednesday, 24 college basketball teams will face of at the Ford Center for the Conference USA Championship.



Wednesday night at Toyota Stadium, the U.S. Women's National Soccer Team takes on Japan in the SheBelieves Cup. Spain plays England during the afternoon.



"I just think that's a bad idea. I think that's a really bad idea. That's how it's going to explode here," said Frisco mom Lauren Sevak.



Both events were planned well before the outbreak. Organizers say they're adjusting by adding portable hand sanitizing stations throughout the venues.



Players say they're taking precautions too.



"I think along with everyone being super safe, washing our hands a lot," said USWNT forward Christen Press.



At the basketball tournament, the pregame handshake has been eliminated and players are being urged to use fist and forearm bumps after the game.

Cleaning crews dressed in full protective suits entered Tadlock Elementary School in Frisco on Monday, hours after the district sent an email to parents letting them know the father of at least one student at the school tested positive for the coronavirus.

Collin County's epidemiology staff are closely monitoring the cases and working to identify additional patients who have come into contact with the family.

There have now been more than two dozen COVID-19 cases reported across the state, including one case announced Tuesday in the Longview area.

For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause severe complications, including pneumonia.

The vast majority of people recover from the new virus. According to the World Health Organization, people with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover. In mainland China, where the virus first exploded, more than 80,000 people have been diagnosed and more than 58,000 have so far recovered.

Texas lawmakers are scheduled to meet in Austin on Tuesday to discuss the state's preparedness for the new virus. Some other legislative meetings have been canceled in light of health concerns.

How to Avoid COVID-19 Infection:

The best way to prevent infection is to take precautions to avoid exposure to this virus, which are similar to the precautions you take to avoid the flu. CDC always recommends these everyday actions to help prevent the spread of respiratory viruses, including:

Wash your hands often with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.

Avoid touching your eyes, nose, and mouth with unwashed hands.

Avoid close contact with people who are sick.

Stay home when you are sick.

Cover your cough or sneeze with a tissue, then throw the tissue in the trash.

Clean and disinfect frequently touched objects and surfaces.

*Information shared from the Office of Texas Gov. Greg Abbott

NBC 5's Maria Guerrero contributed to this report.