The first patient diagnosed in the US with Ebola is on a ventilator and kidney dialysis, as officials monitor those with whom he came in contact.
美国首位确诊的埃博拉病毒患者目前靠呼吸机与肾透析维持生命，当局正密接监视着曾与他接触过的人。
Thomas Eric Duncan's liver function has improved but could fluctuate in the coming days, said the Dallas hospital where he is in isolation.
The current outbreak of Ebola has killed about 3,400 across West Africa.
But no new diagnoses have been confirmed in the US since Mr Duncan's on 30 September.
Experimental drug
President Barack Obama has said the US was preparing a screening regimen for air passengers from countries affected by the outbreak.
Ebola spreads through contact with bodily fluids and the only way to stop an outbreak is to isolate those who are infected. Ebola patients only become infectious after they show symptoms of the disease, such as fever.
There have been nearly 7,500 confirmed infections worldwide, a figure health officials say is probably an undercount. Liberia, Sierra Leone and Guinea have seen the vast majority of infections.
On Tuesday, US Centers for Disease Control and Prevention Director Dr Tom Frieden said Mr Duncan was being treated with the experimental drug brincidofovir, originally developed to fight several other viruses.
He remains in a critical condition in Texas Health Presbyterian Hospital.
His son, Karsiah Duncan, a Texas resident and student at Angelo State University, asked Americans to pray for his mother, who is currently in isolation in Dallas, and for his father to survive.
The younger Mr Duncan also thanked Mr Obama for sending troops to help combat the transmission of the disease in West Africa.
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