Two patients are hospitalized in the United States with Ebola, the deadly infectious disease that has killed thousands of people in West Africa and recently emerged in the U.S. and Europe. Public-health officials across the country are taking steps to ensure that the virus does not get a foothold in North America. A look at the essential developments worldwide:
Three more people are under quarantine at a Madrid hospital where a Spanish nurse became infected. More than 50 other people who may have been exposed to the virus are being monitored. The nurse, who had cared for a Spanish priest who died of Ebola, was the first case transmitted outside of West Africa. Officials said she had changed a diaper for the priest and collected material from his room after he died. Dead Ebola victims are highly infectious. In West Africa, their bodies are collected by workers in hazmat outfits.
Ebola has killed more than 3,400 people in West Africa and infected at least twice that many, according to the World Health Organization. The virus has taken an especially devastating toll on health care workers, sickening or killing more than 370 of them in the hardest-hit countries of Liberia, Guinea and Sierra Leone — places that already were short on doctors and nurses before Ebola.
THE U.S. PATIENTS
An NBC News cameraman hospitalized in Nebraska became the fifth American with Ebola to return to the U.S. for treatment during the latest outbreak. A Liberian man is in critical condition with the disease at a Dallas hospital. He is on a ventilator and receiving kidney dialysis. Officials said he was showing improved liver function on Tuesday, the same day the Rev. Jesse Jackson organized a prayer vigil outside Texas Health Presbyterian Hospital.
THE WAY IT SPREADS
The virus that causes Ebola is not airborne and can only be spread through direct contact with the bodily fluids — blood, sweat, vomit, feces, urine, saliva or semen — of an infected person who is showing symptoms.
There are no approved medications for Ebola, so doctors have tried experimental treatments in some cases, including drugs and blood transfusions from others who have recovered from Ebola. The survivor's blood could carry antibodies for the disease that will help a patient fight off the virus.
Both the American video journalist being treated in Nebraska and the patient in Dallas are receiving the same experimental drug called brincidofovir, an oral medication developed to fight several other viruses. Laboratory tests suggested it may also work against Ebola.
Until Duncan's diagnosis last week, Ebola had never emerged in the United States. But other related viruses have been here, including a case of Marburg virus, which manifests as a viral hemorrhagic fever and is considered just as deadly as Ebola, and four cases of Lassa fever in the past decade.