Deep in the jungle of the DR Congo, medical sleuths are trying to track down the origins of the latest Ebola outbreak in the country.
It is a different strain than the one that has swept three west African countries this year, killing nearly 4,900, and its toll of 49 so far is extremely modest in comparison.
Their all-terrain vehicles bounce along gutted roads in the northwest of the vast country where the outbreak began in late July and has been contained.
Pinning down its source, and learning more about how it acts and develops, are keys to fighting the virus better.
The epidemic in the Lokolia region of Equateur province some 800 kilometres (500 miles) northeast of the capital Kinshasa is the seventh in the country since the virus was first discovered in 1976.
As a result, the DR Congo is more familiar with the disease than the countries engulfed in the current crisis -- Guinea, Liberia and Sierra Leone -- but its secrets persist.
The DR Congo outbreak was initially traced to a woman who died shortly after preparing bush meat that that been hunted by her husband, a pastor.
Today experts are almost certain that she was not the "index case".
"She was the first person to have tested positive for the disease in the lab, but not the first person to die of it," Benoit Kebela, an epidemiologist at the DR Congo health ministry, told AFP.
Kebela, who recently spent some time helping out in Guinea, is a veteran of several Ebola epidemics in the DR Congo.
Around 15 kilometres (nine miles) southwest of Lokolia, three doctors get out of the vehicle in Ikanamongo, a village of a few cinder-block houses with roofs fashioned from tree branches.
A few dozen people rush to meet the team, but they keep their distance to avoid any possible contamination.
- 'All the pigs died' -
The pastor, Doudou Bobua, said his late wife came into contact with two other women, "one of whom died before her, showing Ebola symptoms, and the other two days after."
Another Ikanamongo resident, Jean-Paul Iloko, said that "before the epidemic hit the village, all the pigs died as well as some other farmyard animals."
Other accounts gathered in the region confirm that a porcine fever epidemic preceded the Ebola outbreak. "When (the pigs) were dying we were eating them without knowing that we shouldn't," Iloko said.
Kebela said it was the third time, after 2007 and 2012, that widespread pig deaths had preceded Ebola outbreaks in humans in the DR Congo.
And it has been established that the pigs that died in 2012 carried the Ebola virus, he said.
The Paris-based World Animal Health Organisation said its veterinarians in Africa are closely monitoring livestock and pets but that for now the role of the pig in the Ebola epidemic remains uncertain.
There are suspicions, but no one has proved the transmission of pig to human, Kebela said.
As a precaution, the authorities have nevertheless banned consumption of both bush meat and livestock. "We are eating manioc leaves, that's it," one resident complained.
After the Ikanamongo visit, the team planned to work the environmental angle, replicating their work during the 2012 epidemic when they took soil samples from places where people prepared the dead for burial.
"We were able to pin down the start of the virus, and that even confirmed to us some cases that we had not" spotted, Kebela said.
The investigation continues.