The Zoonotic Tuberculosis Syndemic: A Literature Review and Analysis of the Scientific Journals Covering a Multidisciplinary Field That Includes Clinical Medicine, Animal Science, Wildlife Management, Bacterial Evolution, and Food Safety

Abstract

The article reviews the steadily increasing literature on tuberculosis outbreaks involving Mycobacterium bovis, a bacillus traditionally associated with cattle and dairy products but in fact syndemic in a wide range of other animals including humans. Six major categories of journals cover this story: human infectious diseases and epidemiology, general human medicine, general veterinary practice, veterinary management of zoonoses and wildlife diseases, major multiscience journals, and microbiology. The journal literature is highly concentrated: Twelve high-impact journals account for more than half the citations, while sixty-seven others account for the remainder. While the incidence of food-borne TB has declined in most of the economically developed Western world, there remains a serious potential for dairy-based flares along the U.S.–Mexican border, for venison-associated outbreaks at the U.S.–Canadian border, and for continuing infection of herds in the United Kingdom due to a stubborn residual pool of infected grazing lands. While the consumption of unpasteurized raw milk and artisanal cheeses is generally inadvisable in many parts of the world, small-scale organic dairy farmers in economically developed countries who are particularly scrupulous in maintaining the health of their herds and cleanliness of the production process pose only a limited threat to public health, although occasional small-scale outbreaks will inevitably occur without pasteurization. However, in poorer countries, and especially in Sub-Saharan Africa, the confluence of wildlife, cattle, dairy operations, and rampant TB involving HIV/AIDS-compromised farm workers and consumers has created a nightmare cycle of infection and reinfection.

Keywords:

• applied ecology
• artisanal cheeses
• bacterial evolution
• beef cattle
• dairy herds
• dairy products
• epidemiology
• host–parasite co-evolution
• molecular evolution
• Mycobacterium tuberculosis
• pasteurization
• raw milk
• slaughterhouses
• syndemics
• tuberculosis
• wildlife management
• wildlife reservoirs of disease
• zoonoses

Acknowledgments

Ms. Hardin and Dr. Crandall gratefully acknowledge the Arkansas Bioscience Institute, which helped support their research.