Zoonosis

Alan Wight imageAlan Wight is the interim Non-statutory zoonoses lead for APHA.  He has worked as a Veterinary Investigation Officer at APHA since July 2004, having previously spent 25 years in mixed general practice. Alan has been involved in the Non-statutory zoonoses Project as a Deputy Lead for five years and has gained considerable experience in zoonotic disease investigations during that time.

The role of APHA in relation to zoonotic disease

Zoonoses are diseases which are naturally transmissible between animals and humans. They can be caused by bacterial, viral, fungal, parasitic or prion pathogens. In one study about 75% of the new diseases that affected humans over the period of a decade were caused by pathogens originating from an animal, or from products of animal origin (LH Taylor et al, 2001).

The majority of human zoonoses cases in the UK are foodborne, which means that infection happens via contaminated food or drinking water, with Campylobacter and Salmonella being the most common causes.

Other zoonotic agents may be transmitted through other routes, such as inhalation, direct contact with diseased animals, vectors or contamination of the environment (non-foodborne transmission routes).

What is the risk to the public?

People working with animals or animal products may be at higher risk of contracting some zoonotic diseases compared to the general population. Occupational risks for those that work with animals include vets, farmers, animal keepers and abattoir workers.

Some leisure activities may also pose a risk, particularly if there is potential for interaction with animals, such as at pet shops, open farms and zoos. Young children, pregnant, elderly or immune-compromised people are more at risk of contracting zoonotic diseases compared to healthy individuals, and extra vigilance is recommended.

Very close contact often happens between pet animals and their owners in the home. Although fewer individuals may be exposed to a zoonotic pathogen at home compared to the number of visitors potentially exposed at an open farm or animal attraction, the consequences for each individual can be serious.

How can you reduce the risk?

To reduce the risk of contracting zoonotic diseases through contact with animals good personal hygiene measures, in particular hand hygiene are crucial. This may also include wearing appropriate personal protective clothing. For more information on foodborne illness in people please refer to the Food Standards Agency.

Investigating zoonotic disease

Investigations of zoonotic disease incidents need close cooperation between different organisations, and APHA is a member of the multi-agency ‘Human-Animal Infections and Risk Surveillance’ (HAIRS) group.

The group helps to facilitate good communication and information sharing between the human and animal health professions by meeting regularly as a forum to identify and discuss infections with potential for interspecies transfer and advising on risk prevention and reduction.

Some zoonotic diseases such as brucellosis, rabies and bovine tuberculosis are notifiable in animals in the UK, which means that anyone suspecting such a disease is legally obliged to inform APHA immediately.

Other zoonoses, such as Salmonella, have specific control programmes in place for certain species. Most other organisms of zoonotic potential fall into the category of ‘non-statutory zoonoses’.

Protocols published by PHE for the investigation of zoonotic disease incidents in people in England and Wales are set out in Guidelines for the Investigation of Zoonotic Disease (England and Wales).

There is similar guidance on the investigation and management of zoonotic disease in people in Scotland, published by NHS Scotland: Guidelines on the roles and responsibilities of agencies involved in the Investigation and Management of Zoonotic Disease in Scotland.

Advice for members of the public planning a trip to animal-associated visitor attractions and other information can be found on the PHE Zoonoses Webpages

What work does the APHA do with zoonotic diseases?

Surveillance of non-statutory zoonoses in farmed and domestic animals is undertaken by APHA, with the aim of providing:

  • Surveillance and consultancy advice to Defra, Welsh Government and other stakeholders in England and Wales, to assist policy makers to protect human health.
  • Consultancy advice to private veterinary practitioners and human health professionals on the risks and prevention of human infection.
  • Field and laboratory support for public health professionals in the investigation of zoonotic incidents and outbreaks.
  • Collaboration with Public Health Authorities for the protection of human health, such as through the Human Animal Infections and Risk Surveillance (HAIRS) group.
  • Scientific research to further our knowledge in zoonotic disease.

Veterinary surveillance is the keystone in the detection of new and emerging threats which may present a threat to public health, as well as to animal health and welfare.

Reference

Taylor LH, Latham SM, Woolhouse ME (2001) Risk factors for human disease emergence. Philos Trans R Soc Lond B Biol Sci. 356 (1411), pp 983-9