US committee reports on ruminants as key source of MAP in food

The US National Advisory Committee on Microbiological Criteria for Foods has published its review 'Assessment of Food as a Source of Exposure to Mycobacterium avium subspecies paratuberculosis (MAP)'. Key conclusions of the report are:

• Current methods for detection of MAP have significant limitations.
• A standard method for the detection of viable MAP cells needs to be developed and adopted by researchers in order to accurately determine the presence and numbers of MAP in foods and other potential sources of exposure.
• Aside from MAP-infected domestic ruminant animals, the organism is found infrequently. This may be a function of low prevalence and/or a consequence of the absence of reliable detection methods.
  If MAP in cattle is controlled, the source of MAP in other animals, food, and water may largely be eliminated.
• Milk, particularly raw milk, may be a likely food source for human exposure to MAP.
• Thermal processes that deliver a 4- to 7-log reduction in the number of MAP cells should be adequate to inactivate the numbers of MAP estimated to be present in raw milk.
• A small percentage (< 3%) of commercially pasteurized
  milk may contain small numbers of viable MAP cells.
• Although the data are limited, cheese made from pasteurized milk is probably not a significant source of exposure to MAP, but the potential for exposure to MAP from milk products made from raw milk is unknown.
• Given the prevalence of MAP in U.S. cattle herds, ground beef may be a potential source of MAP.
• MAP survives in cattle feces, water, and soil and is found in many wild animals; therefore, farm runoff may potentially contaminate irrigation water, which can come in contact with fruits and vegetables and result in human exposure.
• Although there is no information to indicate that municipal drinking water is a source of human exposure to MAP, further study is needed.
• Although humans may be exposed to MAP through a variety of routes, including food and the environment, determination of the frequency and amount of exposure will require additional research.

The Committee was not being asked to consider the question of whether or not MAP is a human pathogen.