The Centers for Disease Control and Prevention issued a travel advisory as it monitors the spread of the Marburg virus in east Africa.
The CDC said there have been cases of the rare disease reported in Tanzania. The agency did not say exactly how many cases were detected there.
The CDC said the cases were found in the country’s northwest Kagera region, near the Uganda border.
Cases of Marburg are rare. Only once in the last 15 years has an outbreak involved more than a dozen cases, the WHO notes. There have been two outbreaks in the last 50 years of the virus resulting in more than 100 cases, the WHO said.
The most recent large outbreak came in Angola in 2005, when 374 cases were reported. The WHO said the outbreak resulted in 329 fatalities. There was also an outbreak reported from 1998 through 2020 in the Democratic Republic of the Congo. That outbreak resulted in 128 deaths.
The virus is spread through contact with blood or body fluids, the CDC said. Symptoms can begin two to 21 days after exposure,the World Health Organization said.
The WHO said that Marburg has a case fatality rate of about 50%, but can vary based on the strain.
Cases “begins abruptly, with high fever, severe headache and severe malaise,” the WHO notes. Detecting the virus can be a challenge given it initially presents symptoms similar to other diseases such as malaria and typhoid fever.
There are no vaccines to prevent the spread, but there are several treatments that have received emergency use authorization from the WHO.
The CDC is not advising against travel to Tanzania as of now. It has tips on its websitefor travelers to prevent catching the virus.