Major flaws in epidemic prevention: human and veterinary medicine lack an ecological perspective
The Council of Agriculture has confirmed that Taiwan's ferret-badger rabies outbreak has now lasted a full month. A few days ago it also grandly convened the "Domestic Rabies Human and Animal Epidemic Prevention Expert Joint Consultation Meeting," inviting experts from the medical field, the veterinary field, epidemiology and wildlife to discuss epidemic prevention strategy together. Although officials summarized the meeting as reaching seven points of consensus and conclusions (for details see the press release), some officials and medical experts, when discussing the rabies outbreak, lacked the open-mindedness to listen to what wildlife experts had to say, ignored the connection between the epidemic and ecology, and fell into narrow professional bias.
More than twenty years ago the United Nations put forward the "One Planet, One Health" initiative, and also proposed the concept of Conservation Medicine, emphasizing that environmental health affects animal health, animal health affects human health, and human health in turn affects environmental health; the three are closely interrelated.
Since human health is the goal of physicians, animal health is the goal of veterinarians, and environmental health is the goal of ecologists, maintaining the health of the planet as one requires the medical field, the veterinary field and the ecological field to join hands and conduct cross-disciplinary integrated research on zoonotic diseases.
Emerging zoonotic diseases discovered in recent years, such as SARS, avian flu, and AIDS HIV, are all related to infection through close contact between humans and wildlife, and cross-species transmission of wildlife diseases is inseparable from human destruction or alteration of the environment.
In this outbreak of rabies in Taiwan's ferret-badgers, although the source of infection has not been determined, it may be closely related to human behavior. These various questions await physicians, veterinarians and wildlife scholars joining hands to find the cause and formulate correct epidemic prevention measures.
Last year (2012), the Council of Agriculture's Animal Health Research Institute sent researchers to visit the US National Wildlife Research Center (NWRC) and the National Veterinary Service Laboratory (NVSL) to observe environmental monitoring and disease control models for pathogens such as rabies, avian flu and transmissible spongiform encephalopathy.
The visiting personnel saw that the US National Wildlife Research Center has ample research funding to hire experienced wildlife husbandry staff, establish biosafety level 3 animal housing, and, for diseases such as highly pathogenic avian influenza, keep wild waterfowl in long-term captivity to study how low-pathogenic avian influenza continually circulates among wild birds and the environment. It has also set up a "tropical biological environment simulation room" to raise exotic species such as pythons and frogs, assessing the adaptability of introduced exotic species and their impact on the domestic ecological environment. They were deeply envious.
This visiting researcher lamented that although Taiwan has abundant wildlife species, government agencies have very little research on wildlife and very little monitoring data on important zoonotic diseases, which is very much worth deep reflection and discussion.
Rabies returned to Taiwan after disappearing for 52 years. To confirm whether wild ferret-badgers were infected with the rabies virus, the Bureau of Animal and Plant Health Inspection and Quarantine had to rely on US CDC experts for the final determination through a transoceanic video conference. All of this highlights that in the past agricultural authorities lacked investment in conservation funding, which created today's predicament.
A NewsMarket reporter recently conducted an exclusive interview with Pei Chia-chi, professor at the Institute of Wildlife Conservation, National Pingtung University of Science and Technology. After compiling the content of "Chasing the source of the rabies virus: could the ferret-badger be a victim?" on tracing the source of the ferret-badger rabies virus, the interview then addressed current epidemic prevention problems and the timing of using oral animal vaccines.
An oral vaccine designed in Spain for wild boar tuberculosis. (Photo / Wang Wen-hao)
Physicians, veterinarians and wildlife scientists should join hands
Q: In this epidemic prevention work, what do you think could be improved?
Pei: In this rabies outbreak, we saw that the Centers for Disease Control under the Ministry of Health and Welfare, which manages human health, the Bureau of Animal and Plant Health Inspection and Quarantine under the Council of Agriculture, which manages animal health, and the Forestry Bureau under the Council of Agriculture, which manages the ecological environment, had weak horizontal communication and cooperation at the start. Many veterinarians do not understand wildlife expertise, and many wildlife experts do not understand veterinary medicine or human medicine. These disciplines need to be integrated. Although it is difficult, it must be done, and it can start from the academic world.
Since the 1940s, 75% of the diseases that had never been found before in human history or that newly emerged are zoonotic diseases, including avian flu, SARS, and the AIDS HIV virus. All of these stem from large-scale human destruction of the environment, which changes the contact between humans and animals. In addition, environmental change and climate warming also alter patterns of disease transmission.
This phenomenon drew international attention very early on, so more than twenty years ago the United Nations put forward the "One Planet, One Health" initiative, emphasizing that environmental health affects animal health, animal health affects human health, and human health also affects environmental health. This is a three-in-one, interlocking issue, which is why Conservation Medicine was proposed, hoping that physicians, veterinarians and ecologists would join hands.
This ferret-badger rabies outbreak is a typical example. Although we still do not know who the reservoir host is, whether an exotic species transmitted it to ferret-badgers or it spread out from ferret-badgers, in either case the disease has broken the line of separation between animals. If a human case unfortunately occurs, then the line of separation between animals and humans will have been broken.
Is the disappearance of this line of separation related to environmental destruction and development, and to climate change? Although information is currently insufficient, my personal intuition is that it is related. Many people say this virus already existed in Taiwan's environment and has only now broken out. But why did it break out? Very likely because environmental change reached a critical point. Of course, this remains to be verified.
Keep your distance from wildlife: the highest principle for avoiding infection
Q: So what relationship should humans maintain with wildlife?
Pei: Just keep your distance. Humans should keep their distance from the Formosan macaques of Chaishan, and also keep their distance from wild birds. Basically, by keeping your distance, not actively making contact, and not interacting, the transmission routes for many diseases disappear.
Taiwanese people are very careless, thinking they are skilled and bold. For example, there are a great many people who actively make contact with macaques, often not knowing how dangerous macaques are. If scratched or bitten, they may become infected with a zoonotic disease.
There are many kinds of zoonotic infectious diseases. Besides parasites and hookworms, there is, for example, simian B virus (a herpesvirus). If transmitted to humans and left untreated, the mortality rate is very high, exceeding 70%, but with treatment, death is almost nonexistent and the mortality rate is very low; the treatment model is similar to that for rabies.
Many emerging diseases pass from wildlife to humans. SARS and the HIV virus are both infections caused by consuming or coming into contact with large amounts of wildlife.
Therefore, in this ferret-badger rabies outbreak, my intuition is that it was caused by human activity, because smuggling of exotic species is also a form of human activity. But if the virus has existed in Taiwan for a long time and is only now breaking out, I believe it is also related to environmental change. (Second in the exclusive interview series)
Recommended reading
NewsMarket exclusive interview - Chasing the source of the rabies virus: could the ferret-badger be a victim?
Liberty Times - Canine distemper crosses species to infect ferret-badgers
One Health, One Planet, One Future