zoonotic diseases

The sun is shining and we are all outside sorting out all those chores we couldn’t do in the rain. We will all be shovelling, sweating, dragging the wheel barrow back and forth, some of us driving the quad with all our tools onboard for the designated job/s. We will also be checking our livestock at the same time and then having a bite to eat and a well earned drink to quench our thirst. But with this wonderful weather and all our hard efforts think of hygiene. The warm weather and bacteria are best friends and it is paramount that hygiene is first and foremost for you, your family and for your visitors.

As you are all aware, all farm animals naturally carry a range of diseases, some of which can also affect humans. Potential pathogens are numerous and include bacteria, viruses, parasites, and fungi but most infections are mild and easily prevented with simple procedures such as wearing protective clothing (overalls), washing hands and using and encouraging others to use our foot dips.

It is also true to say that some people are particularly susceptible to some diseases that are carried by pigs. For example, an individual who has a very low immune system may suffer with extreme affects from a Salmonella infection contracted from a pig.

I would like to draw your attention to the pig specific zoonotic diseases (from pig to human) not all are relevant to us in the UK but I thought I would include as many as I can. I hope you find it useful.

Transmission
For diseases to be transmitted from pigs to humans, organisms are either ingested, vaccinated or inhaled. Knowing this presents a clear opportunity to prevent infection. For example, if people washed their hands before handling food or touching their mouths, the likelihood of accidentally ingesting any bacteria, e.g., Salmonella, Toxoplasma, or Campylobacter, would drop dramatically. However there are known factors that will increase the susceptibility of individuals such as stress, fatigue, poor general health, low immune system and age.

Ingestion: The majority of zoonotic diseases for us pig keepers come about by eating the infected organism. Breaking the cycle is all about personal hygiene. Always wash your hands before eating, smoking, or touching your mouth.

Inoculation: Tetanus is the most serious disease for pig keepers as the bacteria can be found in pig faeces or soil infected with faeces from pigs (as well as other animals). Although disease is rare, infection is serious. The bacteria usually enters the body through a wound. Tetanus may result in stiffness and muscle spasms and in worse cases can cause death. As you all know a vaccine is available.

Inhalation: Although the inhalation of dust and other matter can be a health hazard it is not the usual mode of transmission for zoonotic pathogens. Having said this the transmission of Streptococcus suis should not be ruled out as children can be affected.

Zoonotic bacteria from pigs

Ascariasis: this roundworm infection is due to ingestion of parasite eggs, and may be related to contaminated food. Clinical signs may include abdominal pain and coughing. Proper hygiene and food handling practices greatly reduce the risk of infection.

Brucellosis: a form of this bacteria can be transmitted from pigs to humans. The disease is serious. Pig keepers are usually exposed by contact with reproductive fluids or tissues. A flu like symptom may be experienced and serious complications may follow. Antibiotic treatment is required. NOT IN THE UK

Campylobacteriosis: a bacteria that is excreted in the faeces or reproductive fluids of infected animals and may be ingested. Campylobacter is an important cause of foodborne illness. It usually causes gastrointestinal illness. Hygienic work and food preparation practices are important in reducing exposure.

Cysticercosis: this parasite can be ingested via undercooked pork. It may cause gastrointestinal signs, or less commonly, neurological disease. Proper cooking eliminates risk of infection.

Erysipeloid: the bacteria (Erysipelothrix rhusiopathiae) is spread by contact and most commonly infects skin wounds. It causes swelling and lesions on the hands - this disease is different from human Erysipelas, caused by a Streptococcus species. Infection is rare. Hygienic work practices are recommended to reduce the risk of infection.

Hepatitis E: this virus is usually spread by ingesting food or water contaminated with infected faeces. A pig specific type of this virus exists in the USA, although it does not cause illness in pigs.

Leptospirosis: spread by contact with infected urine or waste. It causes general flu-like symptoms in people. Hygienic work practices are recommended to reduce the risk of infection.
Listeriosis: a bacteria that is usually spread by contact with infected waste, contaminated food, or soil. This pathogen may cause flu like symptoms, or gastrointestinal upset.

Ringworm: a fungi that is spread by contact and can occasionally cause itching, hair loss, and scaly skin in people. People are much more likely to contract ringworm from any livestock other than pigs. Avoid contact with suspect lesions, and use hygienic work practices to reduce exposure and risk of clinical disease.

Salmonellosis: this bacterial agent is spread by ingestion of fecal matter via contaminated food or objects, including your hands. Salmonella is an important cause of foodborne illness.

Diarrhoea, fever, or abdominal cramping are experienced. Hygienic food preparation practices, and proper cooking, are recommended.

Scabies: pig-specific mites can survive on humans, but cannot reproduce; they may cause temporary itching and redness.

Mange: can be a significant problem in some pig herds, but the risk to humans is minimal. Wear overalls and gloves when treating pigs and to avoid cross contamination change overalls and boots.

Streptococcus suis: spread by contact and often enters through wounds. Although disease is relatively rare, it may be quite serious and includes blood and brain infections. Good hygiene, and covering wounds/abrasions, is recommended to reduce exposure. Prompt treatment with antibiotics is critical in cases of neurological disease.

Swine influenza: these viruses most likely spread to people by contact with respiratory secretions of sick pigs. Many cases of swine influenza in humans are probably undiagnosed because of their clinical similarity to human influenza infection. Good hygiene is recommended to reduce exposure.

Tetanus: this bacterium can be found in pig faeces or soil infected with faeces from pigs (as well as other animals). Although disease is rare, infections are serious. The bacteria usually enters the body through a wound. Tetanus may result in stiffness and muscle spasms.

Toxoplasmosis: infective forms of this parasite can be ingested when people consume undercooked meat products. This infection is not uncommon, but most infections are asymptomatic. Clinical signs range from mild to severe, particularly in pregnant women or others with weak immune systems. Infections can be treated with antibiotics.

Trichinellosis: this parasite can also be ingested via undercooked pork. Infection is very rare in the UK. Clinical signs may be gastrointestinal or neurological. Proper cooking and/or freezing virtually eliminate risk of infection. Please note you should NOT be subject to charge from your abattoir for the testing of Trichinella.

Please remember:
· Prompt treating or disposal of infected animals
· Adequate disposal of infected tissues
· Proper cleaning of contaminated sites
· Proper use of personal protective equipment
· Use eye protection and gloves when necessary