Kenya confirms four new Ebola cases, including three health workers, in the first infections passed on inside the country

The virus has crossed the line Kenyan officials were working to hold. The health ministry confirmed four new cases of the Bundibugyo strain of Ebola on Saturday: three health workers, two men and a woman aged 29, 35 and 32, who managed the country's first patient on October 3 and 4, and a male relative of that patient who had been in quarantine since October 6. All four were already in quarantine when they developed symptoms and were diagnosed, and the ministry said there is no evidence the virus is spreading in the community.

The first Kenyan patient was a man who had been ill in Congo for about a month before travelling by road through Uganda and flying to Nairobi on October 3. He died on October 5. The second and third patients confirmed earlier are stable and responding well to supportive treatment. Of 130 listed contacts, 128, or 98.5 percent, have been traced and placed in quarantine, the ministry said, above the 85 percent benchmark it cited as needed to break the chain of transmission, as of October 17.

Kenya's cases are linked to the Ebola epidemic in Congo, the second largest outbreak ever recorded, with more than 9,000 cases and more than 4,000 deaths. There are no approved vaccines or treatments for the Bundibugyo strain. The arrival of the virus in Nairobi has raised questions about screening at the Congo and Uganda border, closed since May, and at Jomo Kenyatta International Airport. The ministry's position is that the system around the cases worked: every new patient was already inside quarantine when the fever came. Whether that holds is now the whole question for Kenya's outbreak.