The MAP Infection | An Introduction
Crohn’s disease is a foodborne zoonotic bacterial infection caused by a pathogen known as MAP. This bold concept is moving from theory to reality. An international research symposium being held August 16 in Deerfield, Illinois will bring to light this new idea as to what causes Crohn’s disease, an idea that offers a path to complete cure.
Hi my name is Mike Collins, I’m a veterinarian and a board-certified microbiologist who spent the majority of his 40 year professional life working on mycobacteria avium subspecies paratuberculosis or simply known as MAP. The views expressed in this video are mine alone and not those of my employer or any other organizations with which I am affiliated.
MAP causes a disease of ruminant animals, such as dairy cattle, that is known as Johne’s disease are paratuberculosis this infectious bacterial disease of the intestine was first reported in the United States in 1908. Since then it has steadily spread among cattle herds to the point that now over 90% of US Dairy herds and roughly 5 to 10% of US dairy cattle are infected. This chronic contagious disease affects all breeds of cattle, sheep and goats along with other wild and domestic ruminants causing diarrhea and weight loss just as you see in this Holstein cow. Newborn animals are most susceptible to infection. The infection is followed by a prolonged incubation period. A time when the animal appears normal but the infection is slowly spreading internally. After sexual maturity and the first calf, MAP infected dairy cattle begin shedding the MAP bacteria in their manure and milk. Later, the animals become test positive on assays for antibodies to MAP, done on blood or milk samples. Finally, the animal develops obvious clinical signs of weight loss and diarrhea. What makes this infection so challenging to control is that the healthy looking infected animals are spreading the infection to young calves on the farm long before the owner realizes it.
MAP causes chronic diffuse granulomatous inflammation in the last part of the small intestine called the Ilium. The cobblestone appearance of the inner surface of the intestine strongly resembles that of a Crohn’s disease patient. Most MAP infections are in food producing animals, particularly dairy cattle and the raw meat and milk from these animals is MAP contaminated. This notoriously hardy and resistant pathogen can survive pasteurization and other manufacturing practices designed to kill off the less hardy pathogens. MAP has been detected alive, by culture methods, from dairy products and meat in multiple countries. If MAP behaves in humans as it does in animals then it is the young that may be the most susceptible to becoming infected. In short, there are many ways that humans can be exposed and kids are probably the most vulnerable to becoming infected.
Multiple studies show that MAP can be detected in patients with Crohn’s disease. This study on pediatric cases of Crohn’s disease in Canada is only one example. In this study they tested three biopsy samples for a specific gene found only in MAP called IS900. The study only designated a child is being MAP infected if all three of those biopsies were IS900 positive. Using this very stringent diagnostic criteria, this study found that 35% of 20 kids with Crohn’s disease were MAP positive in the Ilium and 26.3% of nine kids were MAP positive in their colon. In both tissues MAP was found significantly more often than in Ulcerative Colitis patients or controls. Medical science, like life, is full of uncertainties and it continues to be faced with challenging conundrums like Crohn’s disease.
Let me try to sort out some of the certainties from the uncertainties and put the MAP risk in perspective.
These are my MAP certainties, and I acknowledge that other experts may disagree.
- MAP is not ubiquitous in the environment and MAP infections are readily preventable.
- Veterinarians have all of the necessary diagnostic tools and knowledge to control MAP infections in animals.
- MAP infected animals lead to MAP contaminated foods. Now you may find this distasteful, but in fact there are no laws preventing MAP infected animals from providing milk or meat for human consumption.
- MAP survives many food manufacturing practices and can be found in retail products.
- MAP is found in people with Crohn’s disease and those human MAP strains have the same genetic fingerprint as those from animals.
Here are some Crohn’s disease certainties.
- The disease is becoming more common a pattern suggestive of an infectious cause.
- Epidemiological studies point to a trigger for Crohn’s disease that is associated with diet.
- The intestinal pathology of Johne’s disease in animals closely resembles that of Crohn’s disease.
- The consensus of case-control studies like the one from Canada I showed earlier, indicate that MAP can be found in Crohn’s patients far more often than in controls.
- The genetic markers linked with Crohn’s disease probably do play a role in the disease process but they cannot be considered a cause of Crohn’s disease. Interestingly, the same genetic markers are also associated with susceptibility to mycobacterial infections.
Okay, how about the uncertainties.
- Well, first of all, we have no idea how many MAP it takes to infect the human of any age and we don’t know if a single large dose of MAP is more likely to cause infection than a daily small dose. For the cause of tuberculosis, a related infection, it only requires 5 to 10 bacteria to infect the human.
- Exposure may lead to infection, but will all MAP infected people progressed to clinical disease?
- Some have suggested that even dead MAP in a food product such as infant formula could trigger an allergic reaction in the gut much like gluten leads to celiac disease in certain genetically susceptible people.
- Lastly, given all the uncertainties and certainties, should the public accept the risk posed by the presence of live or dead MAP in food.
You may find this information shocking and you may be asking yourself why veterinarians or USDA and FDA officials allow MAP to get into the food supply. The answer is fairly simple, public health officials have not designated MAP as a zoonotic pathogen, meaning a pathogen transmissible from animals to humans.
The US Centers for Disease Control and Prevention is one agency that seems responsible for making such determinations. The root director is Dr. Tom Frieden and M.D. with a Masters in public health under him is the office of infectious diseases led by deputy director Rima Khabbaz. Within this section of CDC is the National Center for Emerging and Zoonotic Infectious Diseases headed by Beth Bell an M.D. with a Masters in Public health.
This is the homepage for the national Center for Emerging and Zoonotic Infectious Diseases. As you see its mission is to protect people at home and from around the world from emerging and Zoonotic an infectious disease, from A to Z. Oddly, there is no mention of Johne’s disease, Paratuberculosis, MAP or Crohn’s disease.
I think this problem is real and I think this problem is large. The time is come to take some precautionary measures to protect public health for everyone’s sake, especially our children.
The upcoming International Research Symposium will explore the idea that Crohn’s disease results from a MAP infection of people. I’ll explain further how this pathogen has become a foodborne infection of humans. Medical gastroenterologists will describe new ways of treating Crohn’s disease based on the concept of Crohn’s as an infectious disease caused by MAP.