(USA TODAY) -- Health officials in the United Kingdom and Hong Kong, fearing that the outbreak of the deadly Ebola virus in West Africa could go global, are quarantining airline passengers from the region who have shown symptoms of the disease.
The outbreak -- the largest in history -- has spread across Guinea, Liberia, Nigeria and Sierra Leone and killed at least 672 people, according to the World Health Organization. The disease has no vaccine and no specific treatment. It has a fatality rate of at least 60%.
In the United Kingdom, the Department of Health confirmed Wednesday that a man who flew into Birmingham airport recently from Nigeria via Paris was clear of the virus despite saying he felt feverish. The U.K. has never seen a case of Ebola.
Newly appointed British Foreign Secretary Philip Hammond planned to chair an emergency meeting later Wednesday on how to stop the spread of the virus.
Two American missionaries working with Ebola patients in Liberia have been diagnosed with the virus.
Ken Isaacs, a vice president of Samaritan's Purse, told The Associated Press that Dr. Kent Brantly -- the 33-year-old medical director for the group's Ebola care center on the outskirts of the Liberian capital of Monrovia -- was stable and in very serious condition. "We are hopeful and prayerful," Isaacs told AP by telephone from the group headquarters in Boone, North Carolina
The other infected American from the North Carolina-based missionary group, Nancy Writebol, had been disinfecting doctors and nurses working with Ebola patients when she was diagnosed with the virus
Bill Bailey, a family friend, told WCNC that Writebol's condition changes "hour by hour."
"Today, [her husband] said she's hanging in there," Bailey said. "She's doing about as well as could be expected. Maybe a little bit better than yesterday -- but very, very weak and tired."
The first American fatality was Patrick Sawyer, a 40-year-old consultant with the Liberian Ministry of Finance, who collapsed upon arrival in Lagos, Nigeria, last week and died Friday in a hospital while under quarantine.
His wife, Decontee Sawyer, who lives in Coons Rapid, Minn., said her husband had been scheduled to fly to Minneapolis on Aug. 16 to attend a birthday party for two of their children. "He could have brought Ebola here," she told The Daily Beast on Tuesday.
In Sierra Leone, Sheik Umar Khan, the doctor leading the fighting against the Ebola outbreak in that country, died from the virus on Tuesday, the country's chief medical officer said, the Daily Mail reports.
In Hong Kong, China' state-run media group CCTV News reported that a female patient with suspected Ebola symptoms had been isolated for treatment in the city. However, the South China Morning Post reported that the woman who had been on vacation in Kenya subsequently tested negative for the disease.
Experts say that in its earliest stages symptoms of Ebola include fever, aches and a sore throat.
WHO says the risk of travelers contracting Ebola is considered low because it requires direct contact with bodily fluids or secretions such as urine, blood, sweat or saliva.
Ebola can't be spread like flu through casual contact or breathing in the same air.
According to WHO, Ebola first appeared in 1976 in two simultaneous outbreaks, in Nzara, Sudan, and in Yambuku, Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name.
Contributing: Associated Press
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