Fears are rising about the spread of Ebola in Texas after health officials revealed an infected patient had come into contact with nearly 20 people over the weekend. 

Health officials said they are working to track down every person who came in contact with the patient, who has been identified in multiple media reports as Thomas Eric Duncan of Liberia. He remains in serious condition at a Dallas hospital. 

{mosads}Duncan could have passed the virus to as many as 18 people between Wednesday, when he began to show symptoms of Ebola, and Sunday, when he entered medical isolation at Dallas Presbyterian. 

Five of the people he came in contact with were children who attended school this week, local health officials said at a press conference without identifying the patient by name. Those people are now being kept at home in case they become ill. 

Government officials from Dallas to the White House sought to maintain calm Wednesday, assuring the public that the virus is not easily transmitted and will be contained.

The chances of an Ebola epidemic in the United States are “incredibly low,” said White House spokesman Josh Earnest. “The reason for that is that it is not possible to transmit Ebola through the air. … The only way that an individual can contract Ebola is by coming into contact with the bodily fluids of someone who is exhibiting symptoms.” 

The assurances from the administration weren’t enough for some Dallas residents, who began pulling their children from school.

Earnest said the administration was not planning travel restrictions or additional airport screenings to prevent the spread of the virus. 

“We’ve provided guidance to pilots, flight attendants and others who are responsible for staffing our transportation infrastructure to ensure that if they notice individuals who are exhibiting symptoms … that the proper authorities are notified,” he said. 

“In light of this incident, the administration has taken the step of re-circulating our guidance … to make sure people are aware there is an important protocol that should be implemented.” 

In Texas, nine experts from the Centers for Disease Control and Prevention (CDC) are working with local health officials to identify any new Ebola cases. 

People who came in contact with Duncan will be monitored for the next three weeks to see if any of them develop symptoms of the disease, officials said.  

A bevy of new details were revealed Wednesday about Duncan, his travel from Liberia and his care in the United States. 

The delivery driver is in his mid-40s and lives in Monrovia; he was sharing a home with a pregnant woman who was sick with Ebola, The New York Times reported. He apparently helped her travel to the hospital four days before his flight. 

Duncan was not exhibiting symptoms at the time of his travel, and officials insisted he could not have infected fellow passengers. He came through Brussels en route to Dallas, a detail revealed Wednesday by a Canadian health official. 

After arriving in Texas, Duncan did not seek medical care until Friday. Though Duncan told a nurse he had been traveling in Western Africa, the hospital sent him home with antibiotics, thinking he had the flu. 

On Sunday Duncan was admitted and placed in medical isolation at the hospital after showing more severe symptoms. 

As information is slowly released, officials have been seeking to tamp down fears that Duncan’s case could cause an outbreak. 

The government has neither confirmed Duncan’s identity nor revealed his flight information, maintaining that none of the other passengers on his flight could have been infected. 

“If you want to do what’s good by your viewers, you will tell them it’s zero chance” of getting Ebola from a person without symptoms, Dallas Mayor Mike Rawlings said Wednesday. 

Ebola is a hemorrhagic fever that initially looks like the flu. Transmitted through contact with blood, urine or other bodily fluids, it kills roughly 1 in 2 people it infects. 

While several people have been brought to the United States to be treated for Ebola — including doctors who were infected while fighting the outbreak in Africa — the Texas patient is the first confirmed case of the virus in the United States. 

“Ebola is a serious disease. … It is a severe disease which has a high-case fatality rate,” said CDC Director Tom Frieden on Tuesday when announcing the infection to the nation.

“Still, there are core, tried-and-true public health interventions that can stop it.”

This story was updated at 7:51 p.m.