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CLAYTON, Mo. (AP) – The 20-something college student didn’t know she had the new coronavirus as she flew home from a study abroad program in Italy, landing at one of the nation’s busiest airports. She took a train to a St. Louis station shared by Amtrak and the Greyhound bus service. Her father, who was exposed to her but shows no signs of illness, went to a coffee shop and took another daughter to a father-daughter dance at a hotel and a house party.

The risk that hundreds of people were potentially exposed to COVID-19 by just one family explains why it is generating so much fear that schools are being closed, athletes are participating in sporting events in empty arenas, and the stock market has bottomed out.

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

The vast majority of people recover.

According to the World Health Organization, people with mild illness get better 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.

The young woman, an Indiana University student from St. Louis County who didn’t know she was infected, returned home from a study abroad program in Italy, which has been hit hard by the virus. The plane landed at O’Hare International Airport in Chicago on March 2.

More than 230,000 travelers pass through O’Hare daily. In January, the Chicago Department of Aviation installed new dispensers for hand sanitizers at O’Hare in high traffic areas, including food courts. The airport now has more than 300 in its four terminals. It also increased workers’ surface cleaning.

After staying with a friend, she took an Amtrak train to St. Louis on Wednesday, departing at a hub called the Gateway Transportation Center in downtown St. Louis. A city spokesman said it’s unclear how many people she would have come in contact with at the station, but another Amtrak train would have passed through at roughly the same time, and the hub also serves Greyhound bus passengers.

Amtrak spokesman Marc Magliari said about 169 customers who purchased tickets for the same train – Amtrak 303 – that the woman rode have been contacted to let them know of the patient’s test result.

“They were encouraged to monitor their health and contact their health provider if they had questions,” he said.

Amtrak canceled one round-trip on the Chicago to St. Louis route on Sunday. The train had returned to normal service by Monday. The train stations in Chicago and St. Louis also are being cleaned.

St. Louis County spokesman Doug Moore said the young woman contacted the St. Louis County Health Department on Thursday to say she was feeling ill. She apparently stayed home and avoided contact with anyone until she was instructed to go to Mercy Hospital for testing on Friday. Meanwhile, County Executive Sam Page said, her family was told to self-quarantine at their home in Ladue.

Health officials learned Saturday that the woman tested positive.

Still, officials said, things got worse when they learned that the woman’s father apparently failed to heed the self-quarantine warning, going to a coffee shop on his own and to a house party and a school dance with another daughter.

“The way the family has reacted to this situation is really a tale of two reactions and the tale of how people should and should not react to the coronavirus,” Page said.

County officials said the father and the younger daughter on Saturday night attended a father-daughter dance for students at Villa Duchesne and Oak Hill School, private Catholic schools that share a campus with a combined 431 students. It’s unclear how many people attended but it would have included students, parents, staff, and workers.

The dance was at the Ritz-Carlton Hotel in Clayton. A statement from the hotel said it is “taking additional steps to perform enhanced cleaning of hotel areas where the event was hosted.”

An online message from Villa, an all-girls school for seventh- to 12th-graders, and Oak Hill, which serves coed preschoolers through sixth-graders, advises students and parents who attended the dance to be attentive to symptoms. Both schools will remain closed this week and through next week’s spring break.

The father and daughter also went to a pre-dance party at the home of a family whose children attend Villa as well as another private school, John Burroughs. Andy Abbott, the head of John Burroughs, said in a note to parents that a “handful” of Burroughs seniors went to the home after the father and daughter left. Although the students had no direct exposure, they won’t be allowed to return to school for two weeks, a period that includes spring break.

County and state health officials have not released details of other places the family members have visited, but workers at Deer Creek Coffee in Ladue called health officials and started cleaning after the family called to say that the father had been there Saturday morning while he was supposed to be quarantined.

“Disinfectant and bleach, a thorough cleaning,” Brent McCarty, owner of Deer Creek Coffee, told the St. Louis Post-Dispatch. “There is no cleaner surface right now than at Deer Creek Coffee. I can promise you that.”

Meanwhile, St. Louis County health officials are still determining who else needs to be notified, checked for symptoms or tested.

By JIM SALTER, Associated Press

The Associated Press receives support for health and science coverage from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.


Associated Press reporter Kathleen Foody in Chicago contributed to this report.