Quick Summary
- Chewed plants prove a simple, noninvasive way to test primates for viruses
- Infectious diseases introduced by humans pose one of the greatest threats to survival of great apes in the wild
- Simple sampling methods are needed to monitor the health of endangered mountain gorillas before a virus becomes an outbreak
Chewed bark, leaves and fruit discarded by mountain gorillas provide a simple way to test the endangered apes for viruses without disturbing them, according to scientists from the University of California, Davis, studying mountain gorillas and golden monkeys in East-Central Africa.
The method is described in a study published recently in the American Journal of Primatology. The study is led by 新澳门六合彩内幕信息 Davis鈥 One Health Institute and Gorilla Doctors, a program led by the nonprofit Mountain Gorilla Veterinary Project and 新澳门六合彩内幕信息 Davis.
鈥淭his is the first time that viruses have been detected on plants chewed by primates,鈥 said lead author Tierra Smiley Evans, a graduate student at the One Health Institute. 鈥淭his is a technique people can use without disturbing the primate鈥檚 natural behaviors.鈥
Keep it simple
Roughly 880 critically endangered mountain gorillas remain in the Virunga Conservation Range, which spans Rwanda, Uganda and the Democratic Republic of Congo, and in the Bwindi Impenetrable Forest in Uganda. Roughly 60 percent of these gorillas are habituated to humans to support ecotourism in the region, putting them at high risk for contacting human pathogens.
Infectious diseases introduced by humans pose one of the greatest threats to survival of great apes in the wild, the study said.
Blood samples, and oral and rectal swabs are often used to detect viruses in primates, but to collect them, primates commonly have to be anesthetized. For the endangered mountain gorillas, anesthesia is only performed when a gorilla is sick or injured due to a human-related cause, not when they are healthy.
Simple, noninvasive sampling methods are needed to monitor the health of the mountain gorillas and other primates, ideally before a virus becomes an outbreak, the authors said.
Picking up after gorillas
In the study, researchers followed the primates at a distance, collected plant samples chewed and discarded by 383 wild mountain gorillas and 18 golden monkeys, and analyzed them to find viruses shed by mouth.
The method proved effective for detecting both RNA and DNA viruses, which is important because RNA viruses are more likely to be transmitted from humans to wildlife and vice versa.
The new noninvasive method could be used in combination with feces and urine sampling to access the most common routes of viral shedding in wild primates. It can also be used to detect viruses in other wild species where health monitoring is critical for conservation management.
Something to chew on
Smiley Evans said that studying the mountain gorillas in their natural environment was 鈥渢he best part of my Ph.D. experience. I got to go with the parks鈥 advanced tracking teams in the morning and be with the group of gorillas for a few hours before the tourists arrived. I got to observe them, see what they were eating, and collect samples. I was able to recognize individuals after several visits to a group. I wouldn鈥檛 trade that experience for anything.鈥
Her study builds on previous work she conducted in Nepal and Uganda with primates. In that research, she coated ropes with jam or mango juice, which the monkeys used as 鈥渃hew toys.鈥 Scientists retrieved the ropes to collect saliva samples.
A 鈥榦ne health鈥 approach
The research is an example of the 鈥渙ne health鈥 approach to public health and wildlife conservation embodied by Gorilla Doctors and the USAID Emerging Pandemic Threats PREDICT project, which is led by 新澳门六合彩内幕信息 Davis One Health Institute director Jonna Mazet. PREDICT conducts global surveillance to detect emerging viruses that move among people, wildlife and livestock before such viruses become pandemic. Gorilla Doctors is the PREDICT implementing partner in Rwanda, Uganda and eastern Democratic Republic of Congo.
鈥淲e need innovative, noninvasive techniques to sample primates that are simple to deploy in remote settings around the globe for surveillance of pathogens that could also affect people鈥 said 新澳门六合彩内幕信息 Davis professor Christine Kreuder Johnson, senior author on this study and director of surveillance for PREDICT.
The study鈥檚 research team included researchers from the Karen C. Drayer Wildlife Health Center and Gorilla Doctors program at 新澳门六合彩内幕信息 Davis; the 新澳门六合彩内幕信息 Davis California National Primate Research Center; One Health Approach in Conservation in Rwanda; Makerere University Walter Reed Laboratory in Uganda; and the Rwanda Development Board in Rwanda.
In addition to Gorilla Doctors technical support and permissions of the governments of Rwanda and Uganda, the study was funded by a William J. Fulbright Fellowship to Smiley Evans and USAID鈥檚 Emerging Pandemic Threats PREDICT project.
Media Resources
Tierra Smiley Evans, 新澳门六合彩内幕信息 Davis School of Veterinary Medicine, (916) 952-0275, tsmevans@ucdavis.edu
Kat Kerlin, 新澳门六合彩内幕信息 Davis News and Media Relations, 530-750-9195, kekerlin@ucdavis.edu