Wildlife Health Specialist Group


Commissioned by the IUCN Species Survival Commission to serve as a first response for wildlife health concerns across the world.

Recent Ebola Hemorrhagic Fever Outbreaks and Wildlife

Recent Ebola Hemorrhagic Fever Outbreaks and Wildlife

Ebola hemorrhagic fever outbreaks have been seen in the Kibaale District of Western Uganda (confirmed as Ebola Sudan) and the Haut-Uele district in Province Orientale in the Democratic Republic of Congo (confirmed as Ebola Bundibugyo). The two outbreaks do not appear to be epidemiologically linked. Members of the IUCN SSC Wildlife Health Specialist Group are involved in the response to both outbreaks.

In Uganda, the outbreak, which was detected in late July 2012, appears to have been contained by late August/early September 2012. In total, 24 cases of suspected and confirmed illness and 17 mortalities were reported. The Ministry of Health worked with partners from the WHO, CDC, the USAID's Emerging Pandemic Threats PREDICT and RESPOND program, Red Cross, Medecins Sans Frontieres (MSF), World Vision, and others on outbreak control efforts (1,2).

In DRC, the Province Orientale outbreak appears to be ongoing and as of September 15, 2012 had been seen in 46 cases (14 confirmed, 32 probable) with 19 fatalities; 26 additional suspected cases of illness are under investigation. The DRC Ministry of Health is working to address the outbreak through its National Task Force, which includes partners from WHO, Medecins Sans Frontieres (MSF), the International Federation of Red Cross and Red Crescent Societies (IFRC), US Centers for Disease Control and Prevention (CDC), United Nations Children's Fund (UNICEF) and the USAID's Emerging Pandemic Threats PREDICT program (3).

The sources have not been identified for either outbreak. Typically, past human Ebola outbreaks have originated from human contact with an infected animal source, and then spread through human-to-human transmission (4). The PREDICT program with its local partners are conducting sampling of bats, primates and rodents in the affected areas to determine whether the outbreaks could be linked to infections in wild populations (5).

Ebola virus represents a significant conservation threat to gorillas and chimpanzees. The western lowland gorilla (Gorilla gorilla ssp. gorilla), a Critically Endangered Species, has suffered severe mortality from Ebola virus since the early 1990's (6); Ebola is viewed as a main risk to the survival of the species. The Endangered chimpanzee (Pan troglodytes) has also seen die-offs, and repeat epidemics have led to chimpanzee mortality events in Gabon and the Republic of Congo (7). Ebola virus has also been seen in duikers (Cephalophus spp.) (8). Ebola Reston virus has been attributed to viral hemorrhagic fever in captive macaques (Macaca fascicularis), as well as imported monkeys from the Philippines (4); the Reston species may also cause asymptomatic infection in pigs (4).

Ape carcasses have been observed prior to human outbreaks in previous instances (8), and past human index cases have been linked to hunting or butchering of infected apes (9). Several species of bats in Africa have been suggested as possible reservoir species for Ebola virus (4,9,10).

Literature Cited

1. World Health Organization Global Alert and Response. “Ebola in Uganda – update”. August 14, 2012. http://www.who.int/csr/don/2012_08_14/en/index.html

2. World Health Organization Global Alert and Response. “Ebola in Uganda – update”. September 3, 2012. http://www.who.int/csr/don/2012_09_03/en/index.html

3. World Health Organization Global Alert and Response. "Ebola outbreak in Democratic Republic of Congo – update". September 18, 2012. http://www.who.int/csr/don/2012_09_18/en/index.html

4. World Health Organization. "Ebola haemmorrhagic fever". 2012. http://www.who.int/mediacentre/factsheets/fs103/en/index.html

5. USAID EPT PREDICT Program Surveillance Personnel. Personal Communication. September 13, 2012.

6. Walsh, P.D., Tutin, C.E.G., Baillie, J.E.M., Maisels, F., Stokes, E.J. & Gatti, S. 2008. Gorilla gorilla ssp. gorilla. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. . Downloaded on 25 September 2012.

7. Oates, J.F., Tutin, C.E.G., Humle, T., Wilson, M.L., Baillie, J.E.M., Balmforth, Z., Blom, A., Boesch, C., Cox, D., Davenport, T., Dunn, A., Dupain, J., Duvall, C., Ellis, C.M., Farmer, K.H., Gatti, S., Greengrass, E., Hart, J., Herbinger, I., Hicks, C., Hunt, K.D., Kamenya, S., Maisels, F., Mitani, J.C., Moore, J., Morgan, B.J., Morgan, D.B., Nakamura, M., Nixon, S., Plumptre, A.J., Reynolds, V., Stokes, E.J. & Walsh, P.D. 2008. Pan troglodytes. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. . Downloaded on 25 September 2012.

8. Leroy E.M. et al. Multiple Ebola Virus Transmission Events and Rapid Decline of Central African Wildlife. Science. 2004; 303.

9. Olson S.H. et al. "Dead or alive: animal sampling during Ebola hemorrhagic fever outbreaks in humans". Emerg Health Threats J. 2012; 5:9134.

10. Leroy E.M. et al. “Fruit bats as reservoirs of Ebola virus”. Nature. 2005: 438.