Agricultural Diseases

Recent blogs on slurry and sheep dipping have looked at a range of issues facing agricultural workers – from environmental implications of sheep dips and slurry to pesticides and livestock. Here, we’re going to identify problems surrounding agricultural diseases as well as the guidance needed for agricultural workers.

This is the third instalment in a series of blog posts which will identify and evaluate the typical environmental impacts associated with day to day farm processes.

Agricultural Diseases

There are numerous agricultural diseases which affect all types of animals associated with farming such as coccidiosis in broilers (poultry) and strangles in horses. Some diseases are highly contagious and are classified as “Notifiable Diseases”. You are legally obliged to report a potential outbreak to the Animal and Plant Health Agency (APHA), even if you only suspect that an animal may be affected. Failure to do so is an offence.

Notifiable diseases can be endemic (which are already present in the UK such as bovine TB) or exotic (which are not normally present in the UK such as foot and mouth disease).

Some endemic and exotic diseases are zoonotic which means they can pass between animals and humans, such as rabies.

The Department of Environment, Food and Rural Affairs (DERA) have provided guidelines if you suspect an exotic notifiable disease, control methods and what to do if a notifiable disease is confirmed.

Below are a few examples of Notifiable Diseases that can also be found on the DEFRA website. A full list of notifiable diseases can be found here.

Foot and Mouth Disease

  1. Affects cloven-hoofed animals (including cattle, sheep and pigs)
  2. Does not affect humans.
  3. Outbreaks in Great Britain have occurred in 1967, 2001 and 2007, the most significant of which was in 2001 when 2,000 cases of the disease were recorded in farms. Approximately 10 million sheep and cattle were killed in order to halt the spread of the disease. The most recent outbreak appears to have emanated from a research facility in Pirbright. Investigations made by the Health and Safety Executive and Brian Spratt of Imperial College concluded that leaking drains may have been the initial cause of the outbreak.
  4. Spread through direct contact with infected animals or indirect via equipment, vehicles, cloths, mud, humans etc. The virus is present in fluid in blisters, saliva, urine, dung and exhaled air before signs of disease appear.
  5. Relevant legislation includes Foot and Mouth Disease (England) Order 2006 and the Foot and Mouth Disease (Control of Vaccination) (England) Regulations 2006.

Anthrax

  1. Affects mammals and birds (including cattle, pigs, horses and sheep).
  2. Affects humans.
  3. The last outbreak in Great Britain was recorded in 2006.
  4. Anthrax was confirmed on a farm in Wiltshire in October 2015 however this case is being closely monitored by Public Health England and thought to pose a very low risk of infection to humans.
  5. Relevant domestic legislation is The Anthrax Order of 1991.

Scrapie

  1. Scrapie is a fatal brain disease that affects sheep and goats.
  2. It is not known to pose a risk to human health.
  3. There are 2 types of Scrapie; Classical and Atypical.
  4. Highly contagious and is spread by colostrum and milk, contamination in buildings, bedding, equipment and pastures were infected animals are kept.
  5. If Scrapie is suspected then the animal will be culled and tested. If it is confirmed that Scrapie is present then you must join the Compulsory Scrapie Flocks Scheme (CSFS).

Bovine spongiform encephalopathy (BSE)

  1. BSE is also known as “mad cow disease” and is a fatal brain disease that affects cattle, sheep and goats.
  2. Effected cattle do not show signs of disease until 4-5 years of age.
  3. BSE can be caused by feeding protein such as Prion to cattle.
  4. Cattle born in the UK before 1st August 1996 are classified as significant risk materials (SRM) and must not enter the food chain as meat may contain significant amounts of prion. A licence must also be applied for prior to moving cattle born before this date.
  5. If your herd is suspected of having BSE, the APHA will impose a movement restriction until testing has been completed.

Avian influenza (bird flu)

  1. Affects birds and humans.
  2. There are two types of bird flu: Highly Pathogenic Avian Influenza (HPAI) which is often fatal in birds and Low Pathogenic Avian Influenza (LPAI) which is less serious and it can cause mild breathing problems. The virus strains change frequently and there is a constant risk that a new strain may spread more rapidly in humans.
  3. The disease is spread from bird to bird by direct contact or from contaminated body fluids and faeces.
  4. The latest case was confirmed in Dunfermline in Scotland (January 2016). This case was thought to have been of low severity, with restrictions to the farm lifted in February.
  5. The government have an alert system which can provide updates of outbreaks for poultry farmers. You must register your flock if you have more than 50 birds.
  6. Further information on biosecurity, movement controls and licences, recent cases and legislation can be found here.

The government website is regularly updated with potential outbreaks and guidance for farmers. For example, DEFRA have predicted that there may be an outbreak of Bluetongue by the end of the summer in 2016. Bluetongue is spread by infected midges between March and September. Relevant legislation includes Directive 2007/75 (EU) and Bluetongue Regulations 2008/Bluetounge (Amendment) Regulations 2012. Bluetongue affects sheep, cows, goats and camelids such as llamas. Humans are not affected by this disease. Whilst it is often hard to predict disease outbreaks, regular updates and monitoring on current situations in the UK can be found online. A risk assessment has been produced to assess the likelihood of occurrence, with the last outbreak in Great Britain recorded in 2007.

Whilst it is important to note the potential chemical contaminative risks that are associated with farming, it is vital to acknowledge the biological risks which can destroy whole flocks and herds and even spread to humans. Disease outbreaks pose great environmental risks and can ruin farmer’s livelihoods. If infected animals are not contained, treated and in some cases disposed of properly, the risk of spreading viruses to future livestock and humans is great as some viruses may last in the ground for years after the original outbreak.

 


References:

2015. Keeping farmed animals– collection Notifiable diseases in animals. https://www.gov.uk/government/collections/notifiable-diseases-in-animals. Date accessed 29/04/2016

2015. Notifiable diseases in animals: Scrapie: how to spot and report the disease. https://www.gov.uk/guidance/scrapie. Date accessed 29//04/2016.

Public Health England. 2014. Zoonotic diseases (zoonoses): guidance, data and analysis. https://www.gov.uk/government/collections/zoonotic-diseases-zoonoses-guidance-data-and-analysis. Date accessed 29/04/2016.

DEFRA. 2014. Foot and Mouth Disease: how to spot and report it. https://www.gov.uk/guidance/foot-and-mouth-disease. Date accessed 29/04/2016.

DEFRA. 2015. Anthrax: how to spot and report it. https://www.gov.uk/guidance/anthrax-how-to-spot-and-report-the-disease. Date accessed 29/04/2016.

DEFRA. 2015. Scrapie: How to spot and report it. https://www.gov.uk/guidance/scrapie. Date accessed 29/04/2016.

DEFRA. 2015. BSE: How to spot and report it. https://www.gov.uk/guidance/bse. Date accessed 29/04/2016.

DEFRA.2016. Avian influenza: how to spot and report it. https://www.gov.uk/guidance/avian-influenza-bird-flu. Date accessed 29/04/2016.

DEFRA. 2016. Bluetounge: How to spot and report it. https://www.gov.uk/guidance/bluetongue. Date accessed 29/04/2016

Risk assessment

Council Directive. 2000. Laying down specific provisions for the control and eradication of bluetounge. http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32000L0075&from=EN. Date accessed 29/04/2016.

The National Archive. 2008. The Bluetounge Regulations. http://www.legislation.gov.uk/uksi/2008/962/contents/made. Date accessed 29/04/2016.

The National Archive. 2012. The Bluetounge (amendment) Regulations 2012. http://www.legislation.gov.uk/uksi/2012/1977/made. Date accessed 29/04/2016.

The National Archive. 2006. The Foot-and-Mouth (England) Order 2006. http://www.legislation.gov.uk/uksi/2006/182/contents/made. Date accessed 30/04/2016.

The National Archive. 2006. The Foot-and-Mouth Disease (Control of Vaccination) (England) Regulations 2006. http://www.legislation.gov.uk/uksi/2006/183/contents/made. Date accessed 30/04/2016.

The National Archive. 1991. The Anthrax Order 1991. http://www.legislation.gov.uk/uksi/1991/2814/contents/made. Date accessed 30/04/2016.

Animal & Plant Health Agency. APHA Alerts and Subscription Service. http://animalhealth.system-message.co.uk/AH_subscribe_index.php. Date accessed 30/04/2016.

APHA & DEFRA. 2015. Keeping farmed animals- guidance: Registering Poultry. https://www.gov.uk/guidance/poultry-registration. Date accessed 30/04/2016.

Horse & Hound. Undated. Strangles. http://www.horseandhound.co.uk/tag/strangles. Date accessed 30/04/2016.

BBC News. 14/09/2007. Pirbright: Labs at centre of outbreak. http://news.bbc.co.uk/1/hi/uk/6931830.stm. Date accessed 07/06/2016.

Leave a Reply