The condition of the first Ebola patient discovered in the United States deteriorated and was downgraded to "critical," a hospital said Saturday.
Thomas Eric Duncan, a Liberian in his mid-40s who traveled to Dallas to visit his relatives, is "in critical condition," a spokeswoman for Texas Health Presbyterian Hospital said without giving further details.
A day earlier, Duncan was listed in "serious but stable" condition. He has been kept in isolation and receiving treatment at the hospital since he was diagnosed with Ebola Tuesday.
Meanwhile, health officials are monitoring about 50 people who may have had direct or indirect contact with the patient. Nine of them had close contact with him and are deemed to be at higher risk. They include four family members and medical staff who had taken care of the patient before knowing he was an Ebola virus carrier.
Officials said the following few days could be critical in determining whether anyone has contracted the disease from Duncan. So far none of those being monitored have exhibited any Ebola symptoms, officials said.
Duncan allegedly began to show symptoms on Sept. 24. The incubation period of the Ebola illness could be as long as 21 days but most patients start showing symptoms within eight to 10 days.
The deadly virus can only be spread through direct contact with the bodily fluids of an infected person who is actively showing symptoms. Early symptoms include fever, headache, muscle pain, diarrhea, vomiting, abdominal pain and unexplained hemorrhage.