Sunday, 29 April 2012

One Health: A Concept for the 21st Century


Dr. Laura Kahn, MD, MPH, MPP, FACP, is a physician and researcher with the Program on Science and Global Security at the Woodrow Wilson School of Public and International Affairs, at Princeton University. Before joining the staff at the University, however, she was a managing physician for the New Jersey Department of Health and Senior Services, a medical officer for the United States Food and Drug Administration in Rockville, Maryland, and attending physician at Prince George’s Hospital in Cheverly, Maryland and a staff physician at Gouveneur Hospital in New York, New York. She is a fellow of the American College of Physicians (ACP) and is a recipient of the New Jersey Chapter’s Laureate Award. Dr. Kahn is also an honorary diplomate of the American Veterinary Epidemiology Society.

Dr. Kahn emphasizing the need for One Health with Nipah Virus and Q Fever as examples.

Dr. Kahn started her presentation with comparing two One Health case studies, which included the Nipah Virus in Malaysia from 1998-1999, and Q fever, which occurred in the Netherlands from 2007 to 2009. She explained that both cases involved the challenges of intensive agriculture, which is becoming increasingly important as the world population increases. Intensive agriculture is needed to feed the seven billion people on the planet and so this issue is becoming ever more pertinent to our lives. Analyzing these cases may perhaps allow us to learn how to avoid catastrophes, such as these, in the future.

The Nipah virus outbreak occurred in the Eastern areas of Malaysia, and was primarily caused by environmental problems. In 1997, a massive deforestation effort was undertaken in this area of Malaysia, in order to clear area for new pig farms. This resulted in a thick haze in the area, and the loss of trees caused fruit bats to lose their natural habitat. As such, pigs and bats came into contact with each other in an area where they never had before. As fruit bats ate and came in contact with contaminated fruits, the bats would transmit viruses and perhaps other pathogens to pigs through their droppings. The pigs would then be a source of exposure to humans, who fell ill due to these viruses.

The signs and symptoms of the Nipah Virus, according to Dr. Kahn, are primarily neurologic, in animals. However in humans, fever, nausea, vomiting, headache, and dizziness are common. She went on to explain that the outbreak of the virus was initially mistaken for Japanese encephalitis (JE), but patients who had been vaccinated against JE were getting sick. Researchers and public health officials started ruling out other diseases until the virus was finally identified in March of 1999. It was also found that the natural host of the virus was in fruit bats and that it was primarily spread by infected secretions.

The virus yielded severe economic consequences for Malaysians, as half the pigs had to be culled to contain the outbreak. Trade with Hong Kong and Singapore, which were strong trade partners with Malaysia before the outbreak, came to a sudden halt. Dr. Kahn explained that had proper planning been employed prior to the deforestation, these economic, public health, and environmental catastrophes could have been avoided.

Similarly, Q Fever could also have been avoided if proper prior planning had been enforced. This outbreak began in dairy goat farms in the Netherlands. The “Q” in Q Fever, according to Dr. Kahn, stands for “query,” because physicians did not know what was causing the disease when it first came to light in the 1930s. However, it was eventually identified as an obligate intracellular organism, which spreads through the air. Humans with the fever do not necessarily show symptoms, unlike in the Nipah virus, as 50% of patients do not report any symptoms following infection. However, the symptoms that are reported include pneumonitis, endocarditis, and granulomas, among other pathologies. In livestock, though, there are very dramatic symptoms. Birth products are highly infectious and infections in pregnant livestock usually presents as spontaneous abortions. Ticks can also spread the infection.

Dr. Kahn went on to explain that many of these problems were due to poor coordination and cooperation between human and veterinary health officials. The challenge for governments was to balance the farmer’s interests with public health. Problems also arose due to the fact that initially the disease was not reportable. Farmers wanted to avoid public stigma and because veterinarians were not required to report the infections, public health officials were not notified and therefore, could not warn humans, which lead to the outbreak spiraling out of control in humans.

These studies illustrate the challenges of intensive agriculture and balancing the need to provide affordable food with environmental health and sustainability, now that we have a global population around seven billion people. Hopefully by remembering the problems that lead to these aforementioned crises, we may be able to avoid them ourselves. However, we must employ the use of a One Health approach when viewing public health problems. It is becoming increasingly difficult, though, because of systematic challenges that prevent the One Health approach from being used. These are listed below:

  • Institutions – Dr. Kahn explained that when viewing and analyzing institutions, their mission statement is critical in understanding its priorities and which issues it will likely pursue. These institutions include international, national, regional, and local infrastructures. Take for example the United States, under the executive branch, the Department of Health and Human Services, and a few other departments, have disease control, prevention, and surveillance for humans in their mission statement. However, no department has animal disease control, prevention, or surveillance in their mission statement, which shows a lack of interest and concern with this issue. Furthermore, it illustrates the fact that these institutions do not understand the interconnectedness between human and animal health. 
  • Funding – This is responsible for, and determines, programs and activities. Funding is allocated to specific agencies, for specific purposes, and these purposes are typically in line with the mission of the organization. Because no specific organization exists solely, or even in part, for the control, prevention, or surveillance of disease in animals, it is not surprise that almost no money goes into animal disease research, compared to human medical research. For example, the budget for the Centers for Disease Control was $11 Billion in 2010, whereas it was $760 Million for APHIS, which is the Animal Plant Health Inspection Service. “Paucity of funds for animal disease surveillance, control, prevention, and research makes implementing One Health difficult,” Dr. Kahn expressed with concern.
  • Education – 137 medical schools exist in the United States, whereas only 28 veterinary schools exist. The same ratio exists around the world, as well. This disproportionate number of medical schools compared to veterinary medical schools is responsible for the vast number of human medical physicians compared to veterinarians, practicing in the United States. Furthermore, a majority of the practicing veterinarians are in small animal care, which is important and is what the public demands, but fewer veterinarians are in large animal practice, which is necessary for proper surveillance of diseases that concern One Health. Dr. Kahn also expressed the need for One Health Degree Programs, which would offer Master’s or Doctoral degree programs in One Health. In addition to biostatistics and epidemiology courses, she elaborated, subjects would include food and water safety and security, environmental health, urban development, agriculture and sustainability, and zoonotic diseases.
  • Attitudes – Perhaps the most challenging issue to tackle, will be this. In a survey of 4897 physicians and 4144 veterinarians across the United States, 80% of MDs and 45% of DVMs replied that they never communicate with their colleagues in the alternate field. They also expressed at a high rate that they would never be interested in doing so. Primarily, specialist physicians said that they would not likely ever encounter rare zoonotic diseases in their practice, so they concluded that conversing with DVMs would not be worth their time. DVMs, though, believe that more interaction would be helpful, but MDs typically have little respect for veterinarians and show little interest in potential zoonotic diseases. This is a cause for major concern, as zoonotic diseases are a stark reality for thousands of people across this country, and physicians should be more educated on this issue.

Dr. Kahn believes that addressing these systematic challenges could be done by creating One Health Organizations, which would have a unified interdisciplinary mission. Their priorities would be, equally, human, animal, and environmental health. Disease surveillance, control, prevention, and research for humans, animals, and the environment would be a core mission of the organization and this would be reflected in its budgets for each of these areas. Furthermore, education could be revamped by implementing Colleges of One Health. These would have under them, schools of Medicine, Veterinary Medicine, Nursing, and Public/Environmental Health. This is a good vision to have for the future.

However, this all depends informing political leaders about the benefits of approaching public health issues with a One Health perspective. This may encourage them to influence policies in such a way that funding for animal, human, and environmental health becomes comparable, unlike the current situation. Medical leaders must also be convinced, as they must acknowledge the inherent interconnection between human and animal health.

Dr. Kahn takes questions from the audience and discusses what small steps can be taken to lead the way for One Health.

Dr. Kahn finished her presentation, the final one of the semester, by acknowledging Drs. Kaplan, Monath, Woodall, and Conti, who have been relentless in their One Health efforts. Following this, she opened the floor up for discussion and questions. Several questions were posed about what the most realistic next few steps would be towards implementing more One Health friendly policies. Several members of the audience, especially physicians, veterinarians, and public health officials, exchanged their ideas about the feasibility of these recommendations and what they believe are the current challenges to implementing One Health in public health issues.  This concluded the spring semester of One Health sessions – leaving us to ponder upon what this generation can do to lead the way for One Health.

Post Authored by Nasir Khatri, B.S. Biochemistry, B.A. Chemistry candidate at North Carolina State University.