Fears that the west African Ebola outbreak could spread to other continents is growing, with European and Asian countries on alert and a leading medical charity warning the epidemic is out of control.
Hong Kong announced quarantine measures for suspected cases, although one woman arriving from Africa with possible symptoms tested negative, while the EU said it was ready to deal with the threat.
The International Civil Aviation Organisation has held talks with global health officials on potential measures to halt the spread.
In Britain, Foreign Secretary Philip Hammond chaired the government's COBRA crisis management committee to assess the situation.
The US State Department has confirmed that one American died from Ebola in Nigeria after being infected in Liberia. Two other American aid workers infected with Ebola - Dr Kent Brantly and missionary Nancy Writebol - are in serious condition, but have shown slight improvement.
The first cases of this outbreak were confirmed in Guinea's remote south-east in March. It then spread to the capital, Conakry, and into neighbouring Liberia and Sierra Leone.
Concern deepened last week when a Liberian-American died from Ebola in Nigeria having travelled from Liberia. Authorities in Nigeria, as well as Ghana and Togo, where he passed through en route to Lagos, are trying to trace passengers who were on the same plane.
Some airlines in the region have cut routes to countries affected by Ebola, despite the World Health Organisation saying it does not recommend travel restrictions as a step to control outbreaks.
Ebola can kill victims within days, causing severe fever and muscle pain, vomiting, diarrhoea and, in some cases, organ failure and unstoppable bleeding.
Since March, there have been 1201 cases of Ebola and 672 deaths in Guinea, Liberia and Sierra Leone, according to the World Health Organisation.
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