The Trump administration is directing all travelers arriving in the United States after recent travel to the Democratic Republic of the Congo, Uganda, or South Sudan to undergo enhanced Ebola screening at Washington Dulles International Airport as health officials respond to a growing outbreak in central Africa.Under the new federal directive announced Thursday, all U.S.-bound people who have been present in the three countries within 21 days of arrival in the United States must enter through the Virginia airport beginning Thursday. The policy excludes cargo-only flights, airline crew members, and aircraft operated by the War Department.

The restrictions come as health officials warn of worsening Ebola outbreaks in the Congo and Uganda. World Health Organization Director-General Tedros Adhanom Ghebreyesus said Wednesday that there are nearly 600 suspected Ebola cases and 139 suspected deaths tied to the outbreak, in addition to 51 confirmed cases in the Congo. Uganda has also reported two confirmed cases among people who traveled from the Congo, including one death.

A U.S. medical missionary working in the Congo also tested positive for Ebola and was transferred to Germany for treatment, according to Tedros.