Amid an outbreak of Marburg virus in Rwanda, travelers coming into the United States who have been in Rwanda in the previous 21 days will be screened starting next week, the US Department of Health and Human Services announced Monday.

Marburg virus is named after the town in Germany where it first emerged. In 1967, there were simultaneous outbreaks at laboratories in Marburg and Belgrade in Serbia (then part of Yugoslavia). The outbreak was caused by African green monkeys imported from Uganda for use in experiments. Seven people died.

WHO has said the risk of the outbreak is “very high at the national level, high at the regional level, and low at the global level.” Marburg virus disease is highly contagious and can cause haemorrhagic fever with a fatality ratio of up to 88 per cent. There is currently no vaccine or specific treatment.