Diseases

Monkeypox

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Questions and answers on Monkeypox and animals (updated 30 May 2022)

Monkeypox is a viral zoonotic disease caused by infection with monkeypox virus that occurs primarily in tropical rainforest areas of Central and West Africa and is occasionally exported to other regions. Monkeypox virus belongs to the Orthopoxvirus genus in the family Poxviridae.

The Orthopoxvirus genus also includes variola virus (which caused smallpox, an eradicated disease), vaccinia virus (used in the smallpox vaccine), and cowpox virus.

In endemic areas, monkeypox virus is thought to be maintained in nature through circulation among a number of susceptible mammals, namely wild rodents (including squirrels and rats), with occasional spill-over to non-human primates and humans.

 

How is monkeypox transmitted?

Transmission of monkeypox virus can occur when a person or susceptible animal comes into contact with the virus from an animal, human, or contaminated materials. The virus enters the body through skin lesions (even if not visible to the naked eye), respiratory tract, or mucous membranes.

Monkeypox virus is transmitted from infected animals to humans or other susceptible animals by direct inoculation via bites, scratches or by direct contact with the body fluids and/or the meat of an infected animal during hunting and other activities involving susceptible animal species.

Human-to-human transmission occurs mainly through close physical contact (e.g., face-to-face, skin-to-skin, mouth-to-mouth, mouth-to-skin contact including during sex). In some cases, ulcers, lesions or sores in the mouth or throat can be infectious, meaning the virus can spread through saliva and respiratory droplets (and possibly short-range aerosols). More studies are needed on whether the virus can spread from breathing and talking.
Thus far, there is no documented evidence of human to animal transmission of monkeypox.

 

Can animals be affected?

Various wild mammals have been identified as susceptible to monkeypox virus. This includes rope squirrels, tree squirrels, Gambian pouched rats, dormice, and non-human primates. Although it may depend on the route of transmission and infectious dose, some species are asymptomatic, especially species suspected of being reservoirs (rodents). Other mammals, such as monkeys and great apes, show skin rashes similar to those experienced by humans.

Thus far, there is no documented evidence of domestic animals, such as cats and dogs, being affected by monkeypox virus. There is also no evidence or reports of livestock infection with the monkeypox virus.

 

What to do when coming across a suspected animal case?

  • Ensure good coordination and communication, using a One Health approach, between wildlife services, veterinary services, and public health services.
  • Use personal protective equipment including gloves, masks, and disposable protective clothing.
  • Take samples if possible (see sample types below) for testing for the presence of virus or evidence of exposure to the virus and send them to the national veterinary or reference laboratory.
  • Notify WOAH – countries are encouraged to report cases of monkeypox in animals to WOAH (by email to [email protected]) as significant animal health information as described in Article 1.1.5 of the Terrestrial Animal Health Code.
  • In addition, cases of infection of wild animals with monkeypox virus are reportable through the voluntary report on non-WOAH listed diseases in wildlife under the disease name “Pox viruses (other than those listed by WOAH) (Infection with)”

 

How to reduce the potential risk of humans infecting animals?

  • Monkeypox is a zoonotic disease, and, despite not having been documented, there is a potential risk of spillback to susceptible animals.
  • Therefore, a collaboration between public health and veterinary authorities is important when managing the potential risk of human to animal transmission. This will help to prevent the disease from being transmitted from humans to susceptible animals at home, in zoos and wildlife reserves, and also to peri-domestic animals, especially rodents.
  • Ensure that all waste, including medical waste, is disposed of safely and is not accessible to rodents and other scavenger animals.
  • People suspected or confirmed to be infected with monkeypox virus should avoid close contact with animals, including domestic animals (such as cats, dogs, hamsters, ferrets, gerbils, etc.), livestock, and other captive animals, as well as wildlife. People should be particularly vigilant around animals known to be susceptible, such as rodents, non-human primates, etc.

 

How can the monkeypox virus be detected in animals?

The appearance of clinical signs, including the presence of visible skin lesions, will depend on the species and age of the animal, as well as on the clade of monkeypox virus causing the infection. Species known as possible “reservoirs” will likely not present any clinical signs of infection. Detailed clinical signs per animal species can be consulted  HERE

In species that present clinical signs of infection with monkeypox virus, animal health professionals should be on the lookout for:

  • Increase in body temperature
  • Appetite changes
  • Conjunctivitis and/or ocular discharge
  • Coughing or sneezing
  • Abnormal sounds during auscultation of the lungs (this is not possible with the required PPE)
  • Skin lesions with or without pruritus
  • Palpable lymph nodes

Samples:

  • Swabs taken from lesions
  • Scabs
  • Conjunctival swabs and/or oral and nasal secretions swabs
  • Blood

Tests:

  • Virus Neutralisation Test (VNT) is the recommended diagnostic test for detecting poxvirus antibodies. It takes 2-3 days to do an Orthopoxvirus VNT and a fluorescently tagged VACV strain can be used to make identification easier.
  • PCR: a pan-pox PCR may be easier to find. However, a specific one to show which strain is causing the infection would be preferable.
  • Serology: Orthopoxvirus ELISAs

 

What is WOAH doing?

WOAH is working with its experts and partners, such as WHO, to gather the latest scientific information and reports from the field. WOAH collates this information and shares it transparently with its members and the general public, aiming to help decision makers to make risk-based decisions considering the latest scientific evidence and avoid unnecessary trade barriers.

Other resources

WOAH

Monkeypox

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WHO

WHO Monkeypox

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CDC

Monkeypox

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