After epidemiologist Eric Leroy saw dogs scavenge the bloody remains of hunting expeditions in the jungles of the African country of Gabon, he wondered if they could contract the deadly Ebola virus. Some 439 blood samples later, Leroy’s fears were confirmed. Dogs—especially rural dogs—carry Ebola antibodies, proof that they were exposed to the virus before developing an apparent immunity. “If the dog can be infected, it can excrete the virus for a few days,” he says. “During this time it can be itself infectious for the human community living near the dogs.”
The study has led to an important tool for epidemiologists. Ebola antibodies in dogs are an indication of virus circulation, key information in regions where tracing the disease’s sporadic and unusual outbreaks has been difficult. When “there are a lot of dogs with antibodies, this means that a lot of dogs were in contact with the virus,” says Leroy, who works for the International Center for Medical Research in Gabon. “This means that the risk is very present . . . higher than elsewhere.”
With this tool, epidemiologists can now use dogs instead of humans to track the spread of the virus. Villagers have been bad sources of information. They don’t report the disease and are reluctant to give blood samples. “They think that if you take their blood, you take a part of them,” explains Pierre Rollin of the Centers for Disease Control in Atlanta. “And they aren’t used to it. There’s no health care where they are.”
