Paratuberculosis Awareness and Research Association logo

News Release

CountryDateRelease Date

United Kingdom

August 12 1998


Retail move to change milk pasteurisation times ineffective.

Claim about milk pasteurisation contradicted by scientific evidence.

The British supermarket giants Tesco, Sainsbury and Safeway have today announced that milk pasteurisation time will be increased from 15 seconds to 25 seconds to reassure the public that their products do not contain Mycobacterium avium subspecies paratuberculosis(MAP), a bacterium that has been linked to Crohn's disease, a chronic Inflammatory Bowel Disease that affects 80,000 people in the United Kingdom.

However, the retail chains claim that the new pasteurisation conditions will eliminate MAP is contradicted by available scientific evidence.

The time necessary to eliminate MAP from milk depends on the number of bacteria in that milk. See table below for the pasteurisation times necessary to eliminate MAP.

Number of bacteria per milllitreRequired pasteurisation time
1,000,00070 seconds
100,00059 seconds
10,00047 seconds
1,00035 seconds
10023 seconds
1011 seconds

The numbers of MAP bacteria present in milk from cattle with Johne's disease can be as high as 1 million bacteria per millilitre or more, as a result of faecal contamination of milk.

Cattle with Johne's disease suffer from severe liquid diarrhoea, which sprays over the rear ends of their bodies, including the udders, leading to faecal contamination of their milk. Infected cattle can shed up to 100 million MAP bacteria per millilitre.

To effectively eliminate the levels of MAP that can be present in milk from infected cattle requires a pasteurisation time of 70 seconds or higher.

Since the numbers of MAP in milk can be even higher than 1 million bacteria per millilitre, the only method of ensuring that live MAP bacteria are not present in milk is to prevent milk from infected cattle from reaching the human food chain.

For a discussion of milk pasteurization and MAP, see the PARA document MAP in retail dairy products.

For further information contact

ContactKaren Meyer
Executive Director, Paratuberculosis Awareness and Research Association, Inc.

Paratuberculosis Awareness and Research Association, Inc.

is a non-profit organization of Crohn's disease patients, their families and friends who are dedicated to the following goals:
  1. To raise awareness of the zoonotic (disease-causing) potential of the bacterium, MAP, in the national community of sufferers of Crohn's disease, in medical, veterinary and food science research communities, in governmental agencies and in the public in general
  2. To urge governmental agencies to directly address control and eventual eradication of MAP from the human environment, particularly from foods of animal origin
  3. To urge governmental and medical research agencies to make funding available for research which will determine the role played by MAP in causing Crohn's disease

Paratuberculosis Awareness and Research Association, Inc.
Box 16219
Temple Terrace, FL 33687-6219

Source:   Contact PARA:
Paratuberculosis Awareness & Research Association