A person who died in Sud-Ubangi province exposed at least 38 people on a long journey that crossed two countries and several previously unaffected provinces.
Frustrated workers are violating funeral protocols.
Officials are using anonymized phone data used to track population movements in the outbreak region.
A new CDC report shows most cases are from new transmission chains.
Since 2015, 176 cases of human H9N2 infection have been documented in China.
Total cases have passed 6,000 in DR Congo.
The Ervebo vaccine, which targets a different strain of Ebola but may offer some protection against the Bundibugyo virus, is being administered to frontline workers.
In total Uganda tracked 20 cases and 2 deaths from the virus.
Two recent reports, however, show promising results for an experimental monoclonal antibody called MBP134.
African health authorities warn the official case totals may be a significant undercount.
