They mask their identities to avoid harassment and violence in Congo, where the epidemic is spreading at the fastest rate since it started in August - and where rampant misinformation fuels a distrust of outsiders in medical garb.
The World Health Organisation (Who) has logged 119 attacks this year against health workers. Eighty-five have been wounded or killed.
Fear is changing tactics among aid staffers, who set out to convince communities that Ebola is real and they were there to help end it.
Now some downplay their mission in public, swapping white coats for street clothes and SUVs for motorbikes that blend into traffic.
“Our staff has to lie about being doctors in order to treat people,” said Tariq Riebel, emergency response director in Congo for the International Rescue Committee, a global aid group.
And the violence hampers the response effort in a more direct way: Ebola infections tend to spike after attacks, experts say, because emergency responders are forced to take cover and halt the distribution of immunity-boosting vaccinations.
The death toll in the central African country reached 1136 this week, government officials said. The infection count, meanwhile, has climbed to 1632 - with 88 more suspected, Congo’s Ministry of Health said.
Concerns are growing that the crisis in Congo’s North Kivu province could become as lethal as West Africa’s battle against the haemorrhagic fever from 2013 to 2016, which killed 11310 people across three countries.
“The tragedy is that we have the technical means to stop Ebola, but until all parties halt attacks on the response, it will be very difficult to end this outbreak,” Who director-general, Tedros Adhanom Ghebreyesus, tweeted on May 10.
An April assault on a hospital killed a Cameroonian epidemiologist in the verdant city of Butembo, the outbreak’s current hot spot. The killing drove hundreds of Congolese doctors and nurses into the streets. Experts are urging the global community to pour more resources into Congo’s struggle. “We’re at a breaking point,” said Stephen Morrison, a senior vice president at the Centre for Strategic and International Studies in Washington.
The Who has twice decided against declaring the outbreak an international public health emergency, as it did for the Ebola epidemic.