American citizens will no longer be allowed to fly directly to the United States from the Democratic Republic of the Congo (DRC) under new federal restrictions aimed at preventing the spread of Ebola. 

Until now, only non-citizens were prohibited from entering the US directly from the DRC. The new ‘Do Not Board’ policy, which is being put together by the Centers for Disease Control and Prevention (CDC) and the Department of Homeland Security, requires US citizens who have been in the DRC within the previous 21 days and “certain travelers” from Uganda and South Sudan to quarantine in a third country before entering the United States. The CDC announced the new restriction July 15.

The move comes as the DRC battles the fastest-growing Ebola outbreak in history. As of today, the Bundibugyo strain of Ebola has sickened at least 2,124 people in the DRC and killed 828.

7 US aid workers quarantining in Kenya

The first Americans affected by the policy are seven aid workers who had been in DRC helping respond to the outbreak. The workers, none of whom is having symptoms, are now quarantining at an isolation facility in Kenya. 

The decision [to quarantine US aid workers in Kenya] was made ‘strictly out of an abundance of caution.’

The workers “voluntarily moved to the Kenya facility for precautionary monitoring and isolation," a US State Department official told Reuters, noting that the decision was made "strictly out of an abundance of caution."

The 50-bed facility, which is being built on an air force base in Kenya, is at the center of legal challenges and public protests by Kenyans who have questioned the decision to house potentially infected people in their country.