For the first time, a virus that causes respiratory disease in humanshas been linked to the deaths of wild mountain gorillas, reports ateam of researchers in the United States and Africa.
The finding confirms that serious diseases can pass from people tothese endangered animals.
The researchers are from the non-profit Mountain Gorilla VeterinaryProject; the Wildlife Health Center at the University of California,Davis; the Center for Infection and Immunity at Columbia University;and the Rwanda Development Board.
Their study, which reports the 2009 deaths of two mountain gorillathat were infected with a human virus, was published online today bythe 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, eachindividual is critically important to the survival of their species,"said Mike Cranfield, executive director of the Mountain GorillaVeterinary Project and a UC Davis wildlife veterinarian. "Butmountain gorillas are surrounded by people, and this discovery makesit clear that living in protected national parks is not a barrier tohuman diseases."
Humans and gorillas share approximately 98 percent of their DNA. Thisclose genetic relatedness has led to concerns that gorillas may besusceptible to many of the infectious diseases that affect people.
The potential for disease transmission between humans and mountaingorillas (Gorilla beringei beringei) is of particular concern becauseover the past 100 years, mountain gorillas have come into increasingcontact with humans. In fact, the national parks where the gorillasare protected in Rwanda, Uganda and the Democratic Republic of Congoare surrounded by the densest human populations in continental Africa.
Also, gorilla tourism -- while helping the gorillas survive byfunding the national parks that shelter them -- brings thousands ofpeople from local communities and around the world into contact withmountain gorillas annually.
The veterinarians of the Mountain Gorilla Veterinary Project, whomonitor the health of the gorillas and treat individuals sufferingfrom life-threatening or human-caused trauma and disease, haveobserved an increase in the frequency and severity of respiratorydisease outbreaks in the mountain gorilla population in recent years.
Infectious disease is the second most common cause of death inmountain gorillas (traumatic injury is the first). "The type ofinfection we see most frequently is respiratory, which can range frommild colds to severe pneumonia," said co-author Linda Lowenstine, aveterinary pathologist with the UC Davis Mountain Gorilla One HealthProgram who has studied gorilla diseases for more than 25 years.
The two gorillas described in the new study were members of the Hirwagroup living in Rwanda. In 2008 and 2009, this group experiencedoutbreaks of respiratory disease, with various amounts of coughing,eye and nose discharge, and lethargy. In the 2009 outbreak, the Hirwagroup consisted of 12 animals: one adult male, six adult females,three juveniles and two infants. All but one were sick. Two died: anadult female and a newborn infant.
Tissue analyses showed the biochemical signature of an RNA viruscalled human metapneumovirus (HMPV) infecting both animals that haddied. While the adult female gorilla ultimately died as a result of asecondary bacterial pneumonia infection, HMPV infection likelypredisposed her to pneumonia. HMPV was also found in the infantgorilla, which was born to a female gorilla that showed symptoms ofrespiratory disease.
Source: University of California - Davis