Human virus linked to deaths of endangered gorillas

A virus that causes respiratory disease in humans has been linked to the deaths of wild mountain gorillas, reports a team of researchers in the United States and Africa.

The finding confirms that serious diseases can pass from people to these endangered primates. Humans and gorillas share approximately 98 percent of their DNA, a genetic fact that led to concern that gorillas may be susceptible to many of the infectious diseases affecting people.

Researchers from the nonprofit Mountain Gorilla Veterinary Project; the Wildlife Health Center at the University of California, Davis; the Center for Infection and Immunity at Columbia University and the Rwanda Development Board have released their findings in the journal Emerging Infectious Diseases, a publication of the U.S. Centers for Disease Control and Prevention.

“Because there are fewer than 800 living mountain gorillas, each individual is critically important to the survival of the species,” said Mike Cranfield, executive director of the Mountain Gorilla Veterinary Project and a UC Davis wildlife veterinarian. “But mountain gorillas are surrounded by people, and this discovery makes it clear that living in protected national parks is not a barrier to human diseases.”

The potential for disease transmission between humans and mountain gorillas (Gorilla beringei beringei) is of particular concern because over the past 100 years, mountain gorillas have come into increasing contact with humans. In fact, the national parks where the gorillas are protected in Rwanda, Uganda and the Democratic Republic of Congo are surrounded by the densest human populations in continental Africa.

Also, gorilla tourism, while helping the gorillas survive by funding the national parks that shelter them, brings thousands of people from local communities and around the world into contact with mountain gorillas annually.

Infectious disease is the second most common cause of death in mountain gorillas (traumatic injury is the first). “The type of infection we see most frequently is respiratory, which can range from mild colds to severe pneumonia,” said co-author Linda Lowenstine, a veterinary pathologist with the UC Davis Mountain Gorilla One Health Program who has studied gorilla diseases for more than 25 years.

Fauna & Flora International (FFI), together with WWF and AWF are founding members behind the International Gorilla Conservation Programme (IGCP) whose mission is to conserve mountain gorillas and their forest habitat. The results of this study are of particular concern to Bruce Liggitt, Africa Programme Coordinator for FFI who said, “Scientists have now confirmed what has long been suspected – that gorillas can die from human respiratory diseases. This shows that we must be constantly vigilant in identifying and addressing threats to mountain gorilla survival.”

The two gorillas described in the new study were members of the Hirwa group living in the Volcanoes National Park in Rwanda, part of the Virunga Volcanoes Massif. In 2008 and 2009, this group experienced outbreaks of respiratory disease, with various amounts of coughing, eye and nose discharge, and lethargy.

Tissue analyses showed the biochemical signature of an RNA virus called human metapneumovirus (HMPV) infecting both animals that had died.

Vale Samehe

In another tragic blow to the mountain gorilla population, a pregnant female gorilla named Samehe in the Nkuringo family group in Uganda’s Bwindi Impenetrable National Park died on March 26 after suffering a serious head wound. It is thought she had sustained the wound from another mountain gorilla, and although the vets with the Mountain Gorilla Veterinary Program intervened multiple times, she never fully recovered and died this week.