Five people out of eight infected with Marburg virus disease died in Tanzania's northwest Kagera region, the World Health Organization (WHO) has said.
The authorities confirmed eight cases after laboratory tests were carried out following reports of infections and deaths in the region.
"Five of the eight cases, including a health worker, have died and the remaining three are receiving treatment," the WHO said, adding that "a total of 161 contacts have been identified and are being monitored."
While Tanzania is struggling with Marburg virus, it is receiving assistance from the WHO.
The international health institution is supporting the Ministry of Health to deploy an emergency team to Kagera to carry out further epidemiological investigations.
"We are working with the government to rapidly scale-up control measures to halt the spread of the virus and end the outbreak as soon as possible," said Matshidiso Moeti, World Health Organization regional director for Africa.
The virus transfers to people from fruit bats and through direct contact with the bodily fluids of infected people, surfaces, and materials.
Marburg virus is of the same type as the virus that causes Ebola. It is highly virulent and leads to hemorrhagic fever, a fatality ratio of which amounts to up to 88%.
At present, vaccines or antiviral medicines approved to treat the virus do not exist. However, there are ways to improve survival, including rehydration with oral or intravenous fluids and treatment of specific symptoms.