Medical services in Guinea are on alert after a man died from Lassa fever, health officials said on Thursday, with some 80 people being monitored for the deadly disease.
Lassa fever is caused by a haemorrhagic virus which belongs to the same family as Marburg and Ebola.
The virus was found in a 35-year-old man from the southwestern town of Kissidougou. He died on January 29 in Mamou, some 400 kilometres (250 miles) away, according to officials.
Kissidougou is where an outbreak of Ebola began in December 2013, leading to thousands of deaths in Guinea, Liberia and Sierra Leone.
"(We) have set to work to see if there are any hidden cases and to trace all the contacts" of the deceased man, said Sakoba Keita from the National Health Security Agency (ANSS).
Keita said it was not yet clear whether this was "an isolated case or an epidemic".
Around 80 people -- 30 in Kissidougou and 50 in Mamou -- are being monitored but none have so far shown any symptoms of the disease, Keita said.
Lassa takes its name from the town of that name in northern Nigeria where it was first identified in 1969.
The virus is spread through contact with food or household items contaminated with rats' urine or faeces, or after coming into direct contact with the bodily fluids of an infected person.
It can be prevented by enhanced hygiene and avoidance of all contact with rats.
Nearly four in five peple who become infected with the virus do not have symptoms of the disease, the World Health Organization (WHO) says on its website.
A Lassa outbreak in Nigeria last year left 171 dead, and a resurgence of the disease there last month killed 16, according to official figures.