Yanthe Nobel walks through the rainforest, looking for a corpse. Reports of a dead elephant, lying in a stream, have reached camp and her job is to figure out what killed it. It’s not the poachers she is worried about — they are increasingly rare here in the Dzanga-Sangha Special Reserve in the Central African Republic. It is the pathogens.

When she and her colleagues find the dead elephant, it turns out to be a baby, less than a year old. Nobel dresses in full protective gear — gown, face shield, gloves — and starts taking samples. “Anthrax is very common around here,” she says, referring to the deadly bacteria that lives in soil as one possible culprit. “It could also be that its mother was poached,” she tells me over Skype, back in camp.

Nobel, a vet and PhD student in epidemiology, has come to Dzanga-Sangha to study viruses, mainly in bats and rodents. Elephants are not usually part of the job — but when a dead animal is found in the forest, she always performs a necropsy. If the cause of death isn’t obvious, and none of the usual pathogens shows up in the field lab, the samples are sent on to a bigger lab in Germany. “You always look for something new,” she says. In the bigger lab, the samples are tested for unknown viruses — pathogens that have not been seen before.