New Research from Kansas State University on The Novel H7N9 Influenza A Virus

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Richt Juergen2x3_3844-002

As part of DugDug’s ongoing series on leading researchers in veterinary science, we have had the unique privilege of interviewing Dr. Juergen A. Richt , a Regents Distinguished Professor and Kansas Bioscience Eminent Scholar at Kansas State University’s College of Veterinary Medicine in theDepartment of Diagnostic Medicine and Pathobiology. He also serves as the Director of the Department of Homeland Security Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD) which is now working with Principal Investigators in 16 different universities, as well as linking to various industrial partners. Dr Richt comes from a farming family (dairy) in Southern Germany and received his Doctorate in Veterinary Medicine (DVM) from the University of Munich and his PhD in Virology and Immunology from the University of Giessen, also in Germany. He completed his postdoctoral/residency studies at The Johns Hopkins University. He was then a Veterinary Medical Officer at the National Animal Disease Center in Ames, Iowa, where he worked on both swine and prion diseases. His latest paper, titled “The Novel H7N9 Influenza A Virus: Its Present Impact and Indeterminate Future”was recently published in the journal Vector Borne and Zoonotic Diseases. The paper studies the life and molecular evolution of the influenza virus.

Dr. Richt told DugDug: “My work in veterinary science – specifically veterinary microbiology – has mainly focused on the animal-human interface, called ’One Health,’ that links human medicine, veterinary medicine and the environment. The overall goal is to develop strategies to identify, control and/or eradicate agents with zoonotic potential, that is animal infections which have the potential to harm both humans and animals.  I am working now especially on influenza viruses in swine. Other interests include Rift Valley Fever Virus, Bovine Spongiform Encephalopathy (BSE) (known as “Mad Cow Disease”), Schmallenberg Virus, African Swine Fever Virus and Borna Disease virus (BDV).

“The pig is a ‘mixing vessel’ for influenza A viruses which can transmit to pigs from both people (i.e. human-like influenza viruses) and birds (i.e. avian-like influenza viruses). When two influenza viruses mix, new influenza viruses are formed that may be more or less virulent than the original parental viruses. Often, viruses are formed from many different animal sources (e.g. human, avian and pig viruses might mix) as had happened in 2008/2009 with the emergence of the pandemic H1N1 2009 virus that began in Mexico, being a mix of human-swine and avian influenza viruses.

“The life and molecular evolution of an influenza virus is unpredictable. We do not know how influenza viruses will change and evolve over their lifetime. My work includes tracking influenza and zoonotic viruses and seeking to understand how they are changing and to what extent these newly created viruses threaten animal and human health and the economy. The majority (~70%) of newly discovered emerging diseases begin in animals and cross over or spill into humans. These diseases are known as “zoonotic diseases” because of their animal origins; however, they can also cross back to humans as recently seen with the pandemic H1N1 virus. Although pathogens can spread from pets such as cats and dogs to humans, with proper hygiene pets are seldom an imminent threat to human health. The dangers arise from wild animals (wild birds and wild mammals), chickens, turkeys and domesticated livestock (e.g., pigs, sheep, cattle, etc.), especially when large numbers of different animal species are gathered in close proximity together, such as in the live (”wet”) animal markets in China. Furthermore, climate change with its unpredictable impact on the ecology of mosquitoes and various rodent species will certainly have a dramatic impact on pathogen and disease ecology especially on pathogens that threaten human health.

“At the present time I am trying to understand both the new H7N9 Influenza A virus that began in March in China, as well as the new respiratory Coronavirus that began last year in the Middle East. Work in my laboratory enables us to understand the makeup of a virus and the extent to which it might threaten human and animal health. For example, with respect to the H7N9 Influenza virus, I and a colleague wrote: “The good news is that there is no evidence of sustained human-to-human transmission, but the bad news is that this newly minted H7N9 avian virus can kill human beings who come in contact with birds or poultry that appear healthy but are in fact carrying a lethal zoonotic agent unbeknown to the human being” (Kahn and Richt, 2013).

“Understanding the genetic makeup of a virus enables us to prepare mitigation strategies in terms of diagnostics, vaccines and antiviral drugs that are essential tools to contain and hopefully eradicate a threatening virus. For each new virus, exploratory work needs to be done in the laboratory in order to determine the molecular make-up of a pathogen and to explore how protective immunity can be created in an animal model – knowledge which can then be translated to both humans and animals. As human beings, we tend to search for culprits as to which species or place is responsible for the emergence and spread of a novel dangerous pathogen. However, the reality is that both microbes and people are striving to live and successfully survive at the animal-human-environmental interface. The precise identification of a new zoonotic pathogen requires animal, human, and environmental scientists to carefully work together in the field (i.e. to understand pathogen ecology) and in the laboratory to ensure: (1) the identification of the original reservoir host wildlife species; (2) its mode of transmission into intermediate host species like poultry or domestic livestock and humans; and (3) its ecology and survival in the environment.

“My findings are essential information for international and national federal entities dealing with disease protection and prevention (i.e. OIE, FAO, WHO, USDA, CDC, DHS, etc.) as well as veterinary and human biologics/pharmaceutical companies trying to produce the necessary detection assays, vaccines and antiviral drugs. However, because of the complexity of the experiments my work needs first to be reviewed by others and then published in peer-reviewed academic journals, so that it is available for other researchers and the public in general. This takes significant amount of time.

“Readers of DugDug will be interested that I work on the second floor of a building, directly above our College of Veterinary Medicine’s hospital for small/companion animals. Research and the practical application of that research are very much a unity here at Kansas State University’s College of Veterinary Medicine in Manhattan, Kansas, and in many other Colleges of Veterinary Medicine in the U.S. and throughout the world.

“Talking to journalists, writing articles for academic peer-reviewed publications and mentoring and encouraging new researchers are all important parts of increasing awareness of ‘One Health.’

“You might wish to draw further information from the last paragraph of the article which I and a colleague wrote: ‘Avian influenza viruses tend to bind to the lower parts of the human lung, which are not easily reached. Therefore, these influenza viruses are not easily transmissible between humans. However, mutations in the avian influenza genome can allow an avian influenza virus to bind to the human influenza receptor. Such mutations would then render these avian viruses transmissible between humans, as it is feared might happen with the H5N1 avian flu virus. It must be emphasized that in the case of the new H7N9 virus this has already partially happened. The amoral reality is that influenza viruses are so unpredictable because they use sophisticated and efficient methods of molecular evolution, adaptation and cross-species transmission. One method is called “reassortment” or “genetic shift,” which is the mixing of the gene segments from different influenza viruses. Another method is called “genetic drift,” which is the constant introduction of mutations into the influenza genome with an unpredictable impact on the phenotype of the newly mutated influenza virus. In the case of H7N9, reassortment of several influenza viruses appears to be the basis of this new strain; and several adaptive mutations have already occurred, leading to a partial adaptation to the human environment. This is a very disturbing reality, as this new avian virus seeks not only to survive in avian species but it is looking for new opportunities in mammalian and human populations. The outcome of this cross-species interaction with this new H7N9 virus is at present indeterminate. What is determinate—what is conclusively settled—is that an increased commitment to the objectives and implementation of the ‘One Health’ approach to medicine in general is now more urgent than ever.”