Colorado went from two cases of the new coronavirus to eight in one day, but health officials say there’s no evidence the disease is spreading through the community or presents a risk to the general public.

Two people in Denver, two more in Douglas County and one patient each in El Paso and Eagle counties tested positive Friday for COVID-19, the disease caused by the new coronavirus that’s spreading globally, county health officials announced.

On Thursday, state officials had announced a Douglas County resident and a California man visiting Summit County had both tested positive.

At least seven of the patients recently had traveled overseas. Two had taken a trip together, but otherwise, there are no known connections between any of the other cases.

Bob McDonald, executive director of the Denver health department and the city’s public health administrator, said there’s no need for residents to change their plans or avoid going out in public. The best thing to do is to practice good hand hygiene, and move away if someone is coughing or sneezing, he said.

“People don’t need to start staying at home,” he said.

All of the cases are listed as “presumptive positive” because they haven’t been confirmed by the U.S. Centers for Disease Control and Prevention, but the state lab results are considered reliable. It typically takes 24 to 48 hours to confirm test results, according to officials with the Denver Department of Public Health and Environment.

The patient in Summit County initially went to a hospital with difficulty breathing and was brought by a private car to Jefferson County, where the altitude was low enough to ease his symptoms. All of the other patients are in isolation in their homes.

Cali Zimmerman, emergency management coordinator for the Denver Department of Public Health and Environment, said public health workers conducted extensive interviews with the two Denver patients and determined there is no risk to the general public. They do that by determining when a person started having symptoms, with a cushion built in to account for people’s imperfect memories, she said.

“We ask a lot of questions about where they were when they became symptomatic,” she said.

Neither of the Denver patients, a man in his 40s and a woman in her 70s, visited any places where they could expose significant numbers of people after developing symptoms, Zimmerman said.

Seven other Denver residents who either traveled to an area where the virus is spreading or live with a person who has been diagnosed with COVID-19 are quarantined in their homes. It’s not clear how many people may be in quarantine statewide. None of the seven had shown symptoms as of Friday, city health officials said.

People who are in quarantine have to stay there for 14 days after their last exposure, or essentially, two weeks after the sick person gets better, Zimmerman said.

St. Anne’s Episcopal School, a private school with students in preschool through eighth grade, asked parents to pick up their children early on Friday after learning one of the Denver patients is the father of a student there. City and state health officials said there wasn’t a significant risk to students, but the school could make its own decision.

The parent hadn’t been on school grounds in roughly a month, but the school opted to send students home to allow more time for a deep cleaning. Classes will go on as normal on Monday.

“We chose a cautious and proactive approach for our community,” the school said in a statement.

Schools occasionally close for a few days to allow for deep cleaning and to stop students from infecting one another. Adams County School District 14 closed Kearney Middle School for one day in December to stop the spread of a gastrointestinal illness, and Mesa County Valley School District closed all schools for several days in November because of an outbreak that was believed to be norovirus.

Health officials in the other counties also said they saw no signs of increased danger to the community. All of the Douglas County patients had traveled abroad recently, according to the Tri-County Health Department. They include a school-aged girl who visited the Philippines, but didn’t return to class after developing symptoms; a woman in her 40s who visited Italy; and a woman in her 70s who took a cruise, whose case was announced Thursday.

“Both of these new cases are from known international exposure, have mild illnesses and are isolated at home, not in a hospital. There is no indication of additional community exposure at this time. Tri-County Health Department staff is monitoring the people who may have been exposed,” Dr. John M. Douglas Jr., the department’s executive director, said in a statement.

An El Paso County man in his 40s tested positive after traveling to California and is in “stable condition,” El Paso County Public Health officials said.

“We hope he is able to make a full and quick recovery,” said Susan Wheelan, director of El Paso County Public Health, in a statement. “Protecting the health of our community is our top priority, and we are doing everything possible to make sure the public is safe.”

An Eagle County woman in her 50s was exposed during international travel. Officials didn’t specify where she had traveled.

The health department advised Denver residents to wash their hands well, avoid touching their faces, cover coughs and sneezes, and stay home if they feel sick. If you need medical care and are concerned you might have COVID-19, call your doctor so the office can take precautions to avoid spreading the disease to other patients.

Colorado is only testing people who have symptoms and traveled to an area where the new virus is circulating or had close contact with an infected person, or who had to be hospitalized because of severe symptoms.

McDonald said he expects additional positive cases, but thinks state and local health departments will be able to keep the situation under control.

“We’re prepared to manage it,” he said.

Denver Post staff writer Jessica Seaman contributed to this report.