Humans have always posed the biggest threat to mountain gorillas, which for decades were poached for trophies and for sale on the world’s wild animal market. One gorilla died in Rwanda in 1992 after stepping on a landmine.
Now, a virus that causes respiratory disease in humans has been linked to the deaths of wild mountain gorillas, according to a study conducted by researchers in Africa and two U.S. universities.
The finding, which for the first time confirms that life-threatening diseases can be transmitted by humans to these critically endangered animals, is of particular concern because the parks where Gorilla beringei beringei is protected in Rwanda, Uganda and the Democratic Republic of Congo are surrounded by the densest populations in Africa, the researchers said.
In addition, those nations count on gorilla tourism -- which brings thousands of people from around the world -- to help earn much-needed hard currency to fund local economies and the national parks that shelter the animals.
The researchers are from the nonprofit Mountain Gorilla Veterinary Project; UC Davis; the Center for Infection and Immunity at Columbia University; and the Rwanda Development Board. Their study was published online Monday by the journal Emerging Infectious Diseases, a publication of the U.S. Centers for Disease Control and Prevention.
Veterinarians had already noticed an increase in the frequency and severity of respiratory disease symptoms -- coughing, eye and nose discharge and lethargy -- among the total 786 wild mountain gorillas left in the world.
The study focused on a 2009 outbreak among 12 gorillas that was blamed for the deaths of an adult female and a newborn infant. Tissue samples from the stricken animals revealed the presence of nucleic acid from a virus known to scientists as human metapneumovirus.
In an interview, Kirsten Gilardi, assistant director of the UC Davis Wildlife Health Center, said, “We don’t know how or when the virus came into this gorilla population, but we do know it was most recently described as a human virus.”
“These animals are so closely related to us that it is not all a surprise they are susceptible to human
pathogens,” she added. “There are some measures we can take to better protect mountain gorillas from incursions of human infections. For example, in an open-air environment, if people stay seven yards away or farther from a gorilla, it would be far less dangerous for that animal.”
-- Louis Sahagun
Photo: Mountain gorilla mother and infant. Credit: UC Davis Wildlife Health Center