Four family members of the Ebola virus patient in Dallas are under orders to stay home so officials can check that they aren’t falling ill, health officials say.

In an update to journalists Thursday, federal, state and local officials said they’re closely monitoring the family members of the patient, identified in media reports as Thomas Eric Duncan, who’s been in isolation in Dallas since Sunday.

The family members were issued a confinement order to ensure they don’t leave the premises, said Dallas County chief executive Clay Jenkins. The order was appropriate "for the safety of the family and the safety of the public."

Dr. David Lakey, the commissioner of the Texas Department of State Health Services, said food and groceries were being delivered to the family and professional cleaning of the apartment is being arranged.

"We didn't have the confidence we would have been able to monitor them the way that we needed," Lakey said.

ebola-dallas-texas-us-liberia

Yasmeen Scott drops off her son and daughter at their school, Hotchkiss Elementary, in Dallas. Hotchkiss has been identified as one of the schools where one or more students came in contact with the first man diagnosed in the U.S. with Ebola virus. (Tony Gutierrez/Associated Press)

The Ebola virus does not spread through casual contact, but through close contact with an infected patient or their bodily fluids.  It can cause fever, vomiting, diarrhea, hemorrhaging and death. 

Disposal of body wastes must therefore be done safely, for example, by sterilizing them under high pressure at a hospital.

"The sheets were placed in a sealed plastic bag and have been in the bag, as well as the belongings of Mr. Duncan; those were also in a bag," Jenkins said.

Health officials are focusing on Duncan’s closest contacts such as family members, checking their temperatures twice a day to identify any illness as quickly as possible.

The closest contacts also include the ambulance workers who brought him to hospital on Sunday and a handful of schoolchildren.

Health officials said they plan to expand their tracing of contacts from a group of 12 to 18 who came in direct contact with Duncan to about 80 others.

Earlier on Thursday, Liberian President Ellen Johnson Sirleaf expressed concerns to CBC’s Adrienne Arsenault about how the man carried the virus from Monrovia to Dallas.

"The fact that he knew [he was exposed to the virus] and he left the country is unpardonable, quite frankly," Sirleaf said. "I just hope that nobody else gets infected."

When Duncan first sought medical care for his symptoms, he told a nurse he had travelled from Liberia but that information wasn’t widely shared with his treatment team, Dr. Mark Lester, who works for the hospital's parent company, told reporters on Wednesday.

With files from The Associated Press and Reuters