Uganda's President Yoweri Museveni has urged people to avoid physical contact, after the deadly Ebola virus claimed one life in the capital, Kampala.
Fourteen people have now died since the outbreak began in western Uganda three weeks ago, he said in a broadcast.
There have been no confirmed cases of the infection spreading in Kampala.
Ebola, one of the most virulent diseases in the world, is spread by close personal contact.
Mr Museveni said health officials were trying to trace everyone who had had contact with victims so that they could be quarantined.
People should avoid shaking hands, kissing or having sex to prevent the disease from spreading, he added.
Mr Museveni said relatives and friends should not bury anyone who is suspected to have died of Ebola.
"Instead call health workers because they know how to do it," he said.
Mr Museveni said seven doctors and 13 health workers at Mulago hospital - the main referral hospital in Kampala - were in quarantine after "at least one or two cases" were taken there from Kibaale district, about 170km (100 miles) west of Kampala.
One victim - a health worker who had been transferred to the capital - later died.
"I wish you good luck, and may God rest the souls of those who died in eternal peace," Mr Museveni said as he ended his address to the nation.
The BBC's Ignatius Bahizi in Kampala says that some people have not yet heard about the latest outbreak of Ebola and are shocked when they find out.
At a bus station in the city centre, our correspondent saw officials warning passengers about the virus and telling them to avoid physical contact.
The first victim of the latest outbreak was a pregnant woman.
It then spread at a funeral, Mr Museveni said.
Uganda has seen three major Ebola outbreaks over the past 12 years.
The deadliest was in 2000 when 425 people were infected. More than half of them died.
There is no vaccine for the virus. Symptoms include sudden onset of fever, weakness, headache, vomiting and kidney problems.