JOHNE’S DISEASE
What is it?
Johne’s disease is caused by Mycobacterium avium subspecies para tuberculosis NMAPO M a bacterium, which causes a chronic and sometimes fatal infection, primarily affecting the small intestine of ruminants, such as cows. It is found around the world.
History
Johne’s was first described in 1895. The last 100 years have seen a steady increase in the number of infected animals within a species, the number of different species infected, and the number of countries in which it has taken root.
Symptoms in animals
In cattle, the main signs are diarrhoea and wasting. MAP symptoms are progressive, and so affected animals become increasingly emaciated and usually die as a result of dehydration and muscle loss. Signs are rarely evident until two or more years after the initial infection.
Source
Johne’s disease is spread primarily by the faecal - oral route. Therefore, one cow with diarrhoea could potentially thoroughly contaminate her surroundings. Confining large numbers of animals in small areas helps to spread the disease and is one reason that it is such a growing threat. Sub- clinically infected animals don’t have symptoms but they can shed the bacteria into the environment, giving MAP the opportunity to become entrenched in am herd before it is apparent that a problem even exists.Every time animals are transported between farms, new herds may be infected. Results from a 2009 government study indicate that 42.5 per cent of UK dairy herds were infected with MAP.
Routes of transmission
There are clinical similarities between Johne’s disease in ruminants and inflammatory bowel disease in humans, leading some researchers to argue that the organism is a cause of Crohn’s.There are two strains of MAP: one that affects cattle, and one that affects goats and sheep. In 2000, a British government survey of retail pasteurised milk found that paratuberculosis bacteria could be ‘grown out’ of three out of every 100 cartons of milk. While pasteurisation kills most bacteria, MAP survives at higher temperatures and for a longer period of time. Second only to prions which cause mad cow disease, MAP is considered the most heat resistant pathogen in the human food chain. Scientific studies argue both for and against an association of MAP with human disease.
Symptoms in people
Crohn’s disease is a chronic inflammatory bowel disease. Sufferers experience profuse, urgent diarrhoea, nausea, vomiting, fevers, severe joint pains, lack of energy and weight loss.The immune system starts attacking the lining of the gut, which becomes swollen and inflamed. In extreme cases, this painful, embarrassing condition can affect any part of the digestive system from the mouth to the anus. The inflammation narrows the digestive tract and can result in excruciating pain during digestion, as well as constant uncontrollable bowel movements.
Treatment
There is no cure for Crohn’s disease, only treatment that can aim to lower the number of times a person experiences a recurrence of symptoms.Treatment may include drugs, nutrition supplements, surgery or a combination. Traditional control methods for treating Johne’s disease in farmed animals have involved culling, segregating infected animals and stricter hygiene.