Op-Ed – Why One Health?

Laura KahnLaura H. Kahn, M.D., M.P.P., General Internist and Research Scholar with the Program on Science and Global Security at the Woodrow Wilson School of Public and International Affairs, Princeton University.

One Health is a concept that seeks to integrate human, animal, and environmental health since all are inextricably linked. This concept is not new and indeed can be traced back to ancient times when the Greek physician, Hippocrates, noted that human health depended on a clean environment. The Romans advanced the concept of a clean environment by building extensive aqueducts and public toilets. Unfortunately, the recognition of the importance of environmental cleanliness waned during the Dark Ages and didn’t appear again until the French Revolution when French physicians promoted the concept of public hygiene.

In the late 19th and early 20th century, physicians and veterinarians worked closely in public health and biomedical research, but collaborative efforts waned as the 20th century progressed and advances in medicine became increasingly specialized. Dr. Rudolf Virchow, a German physician (1821-1902), coined the term “zoonosis” and stated, “…between animal and human medicine there are no dividing lines—nor should there be.” He established the field of veterinary pathology and advocated for food safety by having veterinarians inspect meat. Despite political opposition, European countries adopted Virchow’s recommended meat inspection policies and the United States subsequently followed. This practice is still done today although not as rigorously as one would prefer 1.

As the 20th century progressed, new infectious diseases such as avian influenza (H5N1), SARS, Nipah virus, and West Nile virus emerged from animals into human populations for many reasons including deforestation, intensive agriculture, and bushmeat consumption. In addition to the naturally occurring emerging diseases, the vast majority of bioterrorist agents such as anthrax, plague, and tularemia and food-borne pathogens, such as Salmonella, Campylobacter, and E. coli are zoonotic in origin as well. The zoonotic origin of many infectious diseases prompted the recognition that there needs to be a more integrated, inter-disciplinary approach, a One Health approach, to health and disease 2.

The deadly food borne outbreak occurring in late May 2011 in Germany is a good example of why a One Health approach is important. The German government began reporting a surge in people being hospitalized with bloody diarrhea and hemolytic uremic syndrome (HUS, a serious kidney disorder) from toxin-producing E.coli bacteria3. As of June 14, 2011, over 3000 people became seriously ill and 36 died. 4 Health authorities finally found the culprit: bean sprouts. This finding should not be a big surprise since bean sprouts have been implicated in many previous food-borne outbreaks. Indeed, since 1990, bean sprouts have been implicated in 45 disease outbreaks5. E. coli resides in the guts of all mammals and is typically a benign commensal organism, part of the body’s natural biome. However, there are variants that produce deadly toxins such the one that has killed 36 people.

The German government has been criticized for it slow, bumbling response to the crisis. Spanish farmers suffered unnecessary economic losses after German officials blamed Spanish lettuce, cucumbers, and tomatoes as the source of the outbreak6. Bean sprouts from an organic farm in Northern Germany were eventually identified as the culprit7. There is evidence that humans are the reservoir for this strain of E. coli. How this novel strain developed should be a top priority for researchers8.

The Centers for Disease Control and Prevention (CDC) estimates that 48 million Americans sicken from food borne illnesses each year; and of these, 3000 die9. It should be anticipated that more food borne and zoonotic diseases will plague human populations since the conditions that promote the emergence of microbes continues. The UN estimates that the human population will increase to over 9 billion people by 2075. These challenges are not going away and will likely only get worse as more people demand more food10. A One Health integrated approach that promotes increased communication and collaboration between the human, animal, and environmental health professionals will be critical to address present and future challenges.

1. Food Safety, Food & Water Watch. http://www.foodandwaterwatch.org/food/foodsafety/
2. Kahn, Kaplan and Steele (2007). Confronting Zoonoses through closer collaboration between medicine and veterinary medicine (as ‘one medicine’). Veterinaria Italiana. 43 (1), 5-19. Available online: http://www.izs.it/vet_italiana/2007/43_1/5.pdf
3. Eurosurveillance editorial team. Information resources and latest news about the Shiga toxin-producing Escherichia coli (STEC) outbreak in Germany available from ECDC. Euro Surveill. 2011;16(23):pii=19886. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19886
4. European Centre for Disease Prevention and Control (ECDC). Outbreak of Shiga toxin-producing E. coli in Germany (14 June 2011, 11:00)
5. Neuman, W. (2011, June 10). The Poster Plant of Health Food Can Pack Disease Risks. The New York Times. Retrieved from: http://www.nytimes.com/2011/06/11/business/11sprouts.html?ref=health
6. Cowell, A. (2011, June 7). Germany Is Criticized Even as E. Coli Outbreak Slows. The New York Times. Retrieved from: http://www.nytimes.com/2011/06/08/world/europe/08ecoli.html
7. Sample, I. (2011, June 10). E coli outbreak: German organic farm officially identified. guardian.co.uk Retrieved From: http://www.guardian.co.uk/world/2011/jun/10/e-coli-bean-sprouts-blamed
8. Scheutz F, Møller Nielsen E, Frimodt-Møller J, Boisen N, Morabito S, Tozzoli R, Nataro JP, Caprioli A. Characteristics of the enteroaggregative Shiga toxin/verotoxin-producing Escherichia coli O104:H4 strain causing the outbreak of haemolytic uraemic syndrome in Germany, May to June 2011. Euro Surveill. 2011;16(24):pii=19889. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19889
9. Centers for Disease Control and Prevention (June 30, 2011). Estimates of Foodborne Illness in the United States. Retrieved from: http://www.cdc.gov/foodborneburden/
10. United Nations, Department of Economic and Social Affairs/Population Division (2004). World Population to 2300. Printed in United Nations, New York. Available Online: http://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf