The patient had been ill for around a month before his death, according to the Africa Centres for Disease Control and Prevention (Africa CDC). The agency's chief, Jean Kaseya, told the BBC the man passed through multiple locations in DR Congo before crossing into Uganda and eventually flying to Nairobi, without his sickness being detected at any screening point.
"We know that he left Buta, a city in [northern] DR Congo, to drive to Kisangani. And from Kisangani, he took a flight to Beni. From Beni, he drove to Uganda. And from Uganda, he took a flight to Nairobi," Kaseya said. "What are symptoms he was presenting? Why was he not detected?"
The case has raised concerns about the effectiveness of screening measures across the region. The current outbreak in DR Congo began in May and has been caused by the Bundibugyo species of Ebola, a relatively rare strain for which no approved vaccine or treatment exists, though trials are under way. Ebola spreads through contact with infected bodily fluids such as blood or vomit.
Kaseya said Africa CDC is investigating the case alongside Congolese authorities, and a team is due to meet with Kenyan health officials. Kenya's health ministry has not yet released details of the patient's travel history or the screening protocols in place at airports and border crossings.