Crohn’s disease: The causes

Crohn’s Disease and MAP Information

Crohn’s is a serious source of prolonged disability and ill-health especially in young adults
In children it can lead to stunted growth and development
CD is not a notifiable disease, so numbers are at best estimates
Thought that 65-80,000 cases in UK, with perhaps 7-8,000 new cases each year
The incidence of CD is increasing, mainly in Western World (Europe/N. America, but emerging in other countries)
There is no co-ordinated programme of research into Crohn’s disease
CD should be a notifiable disease so that the extent of the problem is identified — as well as areas of increased risk.

Mycobacterium paratuberculosis (MAP) has a very low level of infectivity
MAP discovered 100 years ago and known to cause chronic enteritis in many animal species, including primates
It can persist for years in animals without causing clinical disease
1994 survey dairy farms SW England showed 1% herds affected within which 2% of animals showed clinical disease
Within affected herds, a further proportion (6-15%) of animals will be sub-clinically affected (i.e. won't appear diseased)
Both affected and sub-clinically affected animals shed MAP into milk
Milk from affected animals is thrown away. Milk from sub-clinically affected animals enters pool for pasteurisation
Current work suggests that MAP may cause chronic enteritis in man in the presence of an inherited/acquired susceptibility
Other factors (co-factors) are involved — an inherited susceptibility, incidental infection (gastro-enteritis or multi-viral infections in childhood) and also psychological conditions which favour disease states
MAP is tolerated by the vast majority of people with no ill effects
For those patients with CD — or close relatives who may share same genetic disposition — it may be sensible to drink UHT milk
Other gastroenterological problems are not associated with this and there should be no concern about drinking milk as usual.