A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

Date: Fri 10 Oct 2014
Source: OIE press release [summ., edited]

[The World Organisation for Animal Health (OIE) has issued on 6 Oct 2014 a technical information sheet on Ebola virus disease (EVD) outlining epidemiological observations and scientific knowledge of the disease including the animal reservoir. The information has been prepared and reviewed by internationally regarded scientific experts, including experts from OIE global Reference Centres and Working Group on wildlife, and was subsequently endorsed by the OIE Scientific Commission on Animal Diseases. We herewith copy for subscribers’ convenience the animal-related segments, “Natural hosts” and “Transmission to humans”. – Mod.AS]

Natural hosts
Field studies and epidemiological surveys in Africa have demonstrated widespread antibody prevalence to Ebolaviruses in fruit bats suggesting that fruit bats may be natural hosts for EBOV. When bats and other vertebrate species were experimentally inoculated, only bats became infected and shed virus in faeces without showing any clinical signs.

Monkeys are not considered as natural hosts because of their high sensitivity to the virus and their high mortality rate when infected.

The related Marburg virus has been isolated from fruit bats (_Rousettus aegyptiacus_) in Uganda.

The role of pigs in EVD epidemiology is unclear. There is no evidence that domestic animals play an active epidemiological role in the transmission of the disease to humans.

Transmission to humans
Ebola is a disease transmitted from wild animals to humans most likely through hunting and collection of sick or dead wild animals and handling or consumption of uncooked bush meat. Although the source of infection for non-human primates often remains unclear, most evidence indicates direct infection from one or more natural hosts. In rural areas fruit bats are a popular source of forest meat for humans and are prepared by hand to be dried, smoked and/or cooked. Infection could also be transmitted to humans by consumption of forest fruits contaminated with bat saliva or faeces.

It is recommended that in affected countries contact with wild animals, including bats, rodents or monkeys should be avoided and that communities in contact with these animals practice basic hygiene measures such as regular hand washing at all times. The hunting of susceptible wild animal species listed above for food in affected countries should be avoided.

Human to human transmission occurs through contact with body fluids of an infected person. It is thought that the current epidemics throughout West Africa originated from a single animal-human transmission event that occurred in the forest at the border between Guinea, Sierra Leone and Liberia.

Communicated by:

[The following list of reported Ebola virus infections in animals has been derived from Ref 1 (for the omitted references, please go to the paper, available free online).

“A total of 51 surveyed locations reporting infections in animals were identified in the literature since the discovery of the disease (Table at http://elifesciences.org/content/3/e04395/T2, map athttp://dx.doi.org/10.7554/eLife.04395.007). These comprised 17 infections in gorillas (_Gorilla gorilla_), 9 infections in chimpanzees (_Pan troglodytes_), 18 in OWFB [Old World fruit bat] and 2 in duikers (_Cephalophus_ spp.). A large proportion of the great ape cases originated from the ROC [Republic of Congo]/Gabon border, coinciding with the main known distributions of both chimpanzees and gorillas and representing a period of well-documented great ape Ebola outbreaks in and around the Lossi Animal Sanctuary. All animal isolations of Ebola viruses have come from countries that have also reported index cases of human outbreaks, with the exception of several seropositive bats from a survey in southern Ghana.”

1. D M Pigott, N Golding, A Mylne, Z Huang et al (2014). Mapping the zoonotic niche of Ebola virus disease in Africa. eLife 2014;3:e04395. DOI: http://dx.doi.org/10.7554/eLife.04395
2. S Funk & P Piot (2014). Epidemiology: Mapping Ebola in wild animals for better disease control. eLife 2014;3:e04565. DOI: http://dx.doi.org/10.7554/eLife.04565
– Mod.AS

A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/promed/p/6075.]

See Also

Ebola virus disease – West Africa (189): Sierra Leone, Liberia, OIE 20141008.2841244
Marburg virus disease – Uganda: (KM) RFI 20141005.2834300
Ebola virus disease – West Africa (183): great apes as sentinels 20140930.2818170
Transboundary disease transmission – USA: risk from wildlife trade 20140831.2738382
Ebola virus disease – West Africa (116): Morocco NOT, Nigeria, bushmeat, more 20140805.2663054
Ebola virus disease – West Africa (68): Liberia, One Health approach 20140619.2553035
Ebola virus disease – West Africa (23): Cote d’Ivoire, bushmeat ban 20140421.2419488
Ebola virus disease – Guinea (02): bat eating banned 20140326.2359281
Ebolavirus aerosol transmission, pig to primate 20121116.1412991
Filoviruses – Indonesia (02): (KA) orangutans, clarification 20121107.1397850
Filoviruses – Indonesia: (KA) orangutans susp. hosts 20121103.1387712
Ebola virus – Indonesia: orangutans, susp. 20120806.1230473
Ebolavirus-like filovirus – Spain (02): (AS) bat 20111023.3157
Ebolavirus-like filovirus – Spain: (AS) bat 20111022.3148
Ebola & Marburg hemorrhagic fever, Egyptian fruit bat – W. Africa 20091006.3469
Ebola hemorrhagic fever, fruit bat – Congo DR, 2007 20090530.2014
Ebola-Reston, porcine – Philippines (10): bat testing 20090316.1075
Ebola-Reston, porcine – Philippines 20081211.3896
Marburgvirus, fruit bats – W. Africa 20070823.2755
Viral hemorrhagic fever – Uganda (Kamwenge): Marburg conf. 20070801.2490
Ebola virus, bats – Central Africa 20051201.3467
Bats, disease reservoir 20051112.3311
Hemorrhagic fever, Marburg virus – Congo, DR 19990506.0748
Ebola: reservoir, stability 19970123.0137
Ebola: reservoir, stability 19970123.0137
Ebola: hunt for reservoir 19961117.1926
Ebola – Zaire: bat reservoir? 19961020.1757
Ebola – reservoir 19950525.0345
Ebola – reservoir 19950515.0288