An outbreak of the deadly Marburg virus has been confirmed in Uganda's Kamwenge district by the health authorities.
Two miners have been diagnosed with the fast-spreading Ebola-like haemorrhagic fever, close to the border with the Democratic Republic of Congo.
One of them has died and about 40 other people working at Kitaka gold mine have been quarantined, officials say.
Marburg has a high fatality rate. The last reported outbreak was in Angola in 2005 when some 300 people died.
The health ministry has urged local people to report any suspicious cases.
Gold mines in DR Congo have been struck by Marburg in the past
Incubation takes up to 10 days and although the last suspected case was reported 15 days ago, there is still a risk that the disease could re-emerge.
"The last case needs to have been seen 21 days ago before we can actually say we've contained it," Sam Okware of Uganda's taskforce on haemorrhagic fevers told the BBC's Focus on Africa programme.
Gold miners in DR Congo have been struck by the disease in the past.
Dr Okware says it is not exactly known what causes Marburg, although birds and monkeys are suspected vectors. Rats and bats also reportedly spread the disease to humans.
"My own impression is that the source of the infection is in the mine itself - because when we went there to check, we found almost 5m birds in the mine and the situation was quite unsanitary," he said.
Early symptoms of Marburg are diarrhoea, stomach pains, nausea and vomiting, which give way to bleeding.
It is spread by the transfer of blood or other bodily fluids.
There is no cure. Infected patients need to be kept in isolation so as to prevent the spread of the virus.