The Human Animal Medicine Project has moved to the University of Washington

The Human Animal Medicine Project has moved to the University of Washington

As of September, 2013, the Human Animal Medicine Project has officially moved to its new home at the University of Washington, where Dr. Rabinowitz is now a faculty member with appointments in Environmental/Occupational Health and Global Health. UW will be an exciting new home for the Human Animal Medicine Project with great strengths in infectious disease research, public health, global health, environmental health, ecology and zoology, and other fields relevant to the human/animal/ecosystem interface. The Human Animal Medicine Project will continue to focus on emerging zoonotic diseases as well as animal and human sentinels for environmental health hazards and comparative clinical linkages between human, animal, and environmental health. 

See the new website at: http://deohs.washington.edu/hamp/

H7N9 Avian Flu in the Air

A recent ProMed posting (Saturday, May 4 2013  Volume 2013 : Number 216) provides an update on the outbreak in China of the H7N9 strain of avian influenza, which as of May 1 has resulted in 127 confirmed human cases, of which 26 (20.5%) have been fatal.  While the virus does not appear to have caused significant human-human transmission, the route of exposure from an animal source to humans is only now beginning to be understood. In a number of cases , there is no history of recent contact with birds or other animals. According to the ProMed posting, an official with the Chinese CDC has indicated that chicken feather plucking machines are suspected of spreading the virus through the air. Feather plucking  machines  (see picture below) can create aerosols of small feather particles as well as droplets of blood and other secretions. Such small particles are capable of being transporters of flu viruses,  and the Chinese CDC official has been quoted as saying “If there is a virus, it can be easily inhaled this way…This is what we suspect to be a major environmental exposure that causes human infections.”  (see the original story here).

Of course, it is not clear what evidence has been collected to support the theory implicating the feather plucking machines. Ideally one would like to see evidence that the virus is present in aerosols created by the machine, that the size of the particles with virus are small enough to remain airborne for significant amounts of time, and that such airborne virus is still viable (as opposed to being present but damaged during transport and not able to be infectious). It would also seem logical that workers close to such machines would be at increased risk of infection, and that a study of such workers would reveal increased rates of infection. At present it seems that such evidence has not yet been documented. Maybe the feather plucking machines are spreading H7N9, but maybe not.

This turn of events reveals once again how little we know about zoonotic (animal to human) transmission of influenza viruses such as avian flu or swine flu. Of course we are still learning how human influenza itself passes from person to person, and the debate continues about the relative importance of human flu transmission over distances in the air as very small particles versus direct contact with secretions or spread by droplets from a sneeze or cough that only travel several feet.  Yet we know even less about how animal flu viruses move around environments where often there are dusts (such as in a barn) or other unusual types of aerosols (such as with feather plucking machines) that potentially can carry viruses for extended distances.

While this recent disturbing outbreak of avian influenza reinforces the need to consider new approaches to vaccination and diagnosis, it should also spur research into the ways that these viruses spread and persist in the environment. Adequate prevention needs to include smart environmental management of infection risk, and answering questions such as “how long can the virus survive in the air?”. “When is it necessary to wear a mask to protect oneself?” And “how can environments be decontaminated in the midst of an outbreak”. Answering such questions will require sampling environments and high risk populations such as workers for evidence of the avian influenza virus, and developing an understanding of how the virus can and cannot travel and persist outside of an animal or human. Without such knowledge, we may miss important opportunities for prevention, and risk either scaring the public unnecessarily, or reassuring them inappropriately.

One Welfare?

Recently a colleague sent me an article that appeared to build on the concept of “One Health Ethics” mentioned in this blog last year (see OneHealth ethics) . Two veterinarians, enrolled in the Congressional Science and Engineering Fellows Program of the American Association for the Advancement of Science have examined the concepts of human welfare, animal welfare, and the welfare of the environment, and proposed that there is a need for a “One Welfare” approach to a large number of issues that cuts across traditional divisions. 

We are not talking about food stamps and entitlements here, we are talking about the need for society to "make decisions in an interdisciplinary frame with a focus on action and a mission of balancing and promoting human and animal welfare in connected ecosystems and societies."

This seems like a welcome antidote to the discussions of human or animal welfare that at times seem to pit one species against each other, or the cost benefit analyses that suggest environmental degradation may be an inevitable a price tag for economic development . It will be interesting to see whether others pick up this theme and begin developing practical applications. 

For One Health Approaches to Succeed, Information Needs to Flow

In considering the different aspects of integrated approaches to human, animal and environmental health along a One Health paradigm, so many of the challenges seem to boil down to the challenge of how to get information to flow in ways it has not in the past. Here are some examples:  

Disease Surveillance:

A number of groups, including the National Academy of Sciences have called for the development of systems that integrate human and animal disease surveillance data. This could allow for improved detection of emerging disease threats in the environment, both infectious and toxic. The Yale Human Animal MedicineProject has performed analyses supporting the promise of such data integration.  But at present, disease surveillance is collected separately by human and animal health agencies, and not shared in a systematic fashion. As a result, we are still limited in our understanding of what the occurrence of disease events in animal populations (think white nose syndrome in bats or colony collapse in honeybees) means for human health. The Canary Database is one resource for at least examining this issue. We are also therefore limited in our ability to detect and predict human health problems related to environmental change. It will take political as well as scientific will to reorganize such information sharing, but it needs to happen.

Environmental risk data:

Part of the challenge of integrating human, animal, and environmental health is having adequate data about environmental risks, whether climate change, wildlife populations, or degree of contamination by biological, chemical, and/or physical hazards. While animal disease data can provide “sentinel” information about environmental risk “shared” by animals and humans, there is often a need to better characterize environments: getting this information often involves getting out in the environment and finding out what is going on, and transmitting that information to both human health and public health and animal health professionals.

 Genomic data:

The genomes of humans and animals hold the key to better understanding key differences and similarities between species that could help improve the health of both humans and animals, discovering new approaches to disease detection and treatment- see Zoobiquity.  Yet this information is complex and vast- and to use it better will take development of new technological approaches for comparing and exploring these genetic linkages. In addition, better understanding of the genetic characteristics of the pathogens that cross between humans and animals (such as influenza) can help anticipate and prevent outbreaks of zoonotic diseases affecting both human and animal populations. The Human Animal Medicine Project is working with several efforts to assemble and analyze genomic data about pathogens, including the GAINS database and Zoophy. Recent breakthroughs in DNA sequencing technology have produced vast databases of such genetic information- what is needed is a path through this thicket of data.

The Microbiome:

A related wealth of genetic information is accumulating about the human “microbiome”: the communities of microbes that call our gut, skin, and other surfaces home, and seem to have a large effect on our health and wellness. How do our microbiomes differ from those of our companion animals or other animals that we contact on a regular basis?  Is the sharing of microbes between humans and animals all negative or could there be some positive aspects to it that have evolved over millennia of coexistence between humans and animals? The Human Animal Medicine project is performing some pilot analyses of this in workers with close exposure to livestock.

Occupational Risk:

On a more basic level, when workers have close contact with animals, such as swine workers working in large production facilities, there is a need to supply them (and their employers) with better information about their occupational risk and ways to reduce such risk. Such information, such as the amount of virus or bacteria that is present in the air and surfaces of barns and other facilities may be critical to decisions about how to protect workers and reduce disease transmission. While this may seem to be sensitive information, better awareness of such information could actually benefit both human health (occupational and food safety) as well as the health of the animals. The Human Animal medicine project is piloting such approaches in workplaces.

The promise of One Health is the concept of rapid information flow between human, animal, and environmental health, allowing for early detection and prevention of emerging disease risks. If these pilot efforts and similar initiatives around the globe continue to bear fruit there is a chance that we are moving in the right direction toward a world with improved health across multiple species in a healthy environment.