The 40-year-old Kenyan man, who died on October 5, was diagnosed with Ebola shortly after being admitted to hospital in the capital, Nairobi.
A family had taken him there shortly after picking him up at the airport. He had traveled from DR Congo, through Uganda and Kenya, without his illness being detected.
Since his death, officials have determined that he had been in contact with 128 people – and as of Tuesday, 113 of them had been found, the health ministry said.
Of these, 108 were quarantined in Kenya and tracing of the remaining 15 was ongoing, it said.
More than 4,000 people have died of Ebola in the DR Congo this year, in the second deadliest known outbreak to date.
The Ebola virus spreads through contact with infected body fluids such as blood or vomit.
“Anyone with fever, unusual fatigue, muscle or joint pain, vomiting, diarrhea or unexplained bleeding should seek immediate medical attention at the nearest health facility,” Kenya’s Ministry of Health said.
The current outbreak in DR Congo, which began in May, was caused by the Bundibugyo species of Ebola, which is relatively rare, with no approved vaccine or treatment – although studies are underway.
Shortly after the DR Congo declared an outbreak of Ebola in May, it was also reported in Uganda, where two people died.
However, the World Health Organization (WHO) declared this county free of the disease in August.
The African Centers for Disease Control and Prevention, the continent’s leading public health agency, reconstructed the Kenyan patient’s movements for the six weeks leading up to his death.
It revealed that he first began to feel unwell in DR Congo on September 15 – and showed how several opportunities to detect the infection were missed, including during several visits to Congolese medical facilities.
He then managed to travel through Uganda and Kenya – and was again not detected on the airport screens.
Health experts say it highlights the limitations of relying on temperature checks and self-declarations.