Volume 16, Number 8—August 2010
Materials Available Online Only
One Health Approach to Influenza: Assessment of Critical Issues and Options1
A task force of experts on influenza, public health, and animal health met at the conference One Health Approach to Influenza: Assessment of Critical Issues and Options in Washington, DC, on December 1–2, 2009. These experts discussed the role of the One Health approach in preparing for and responding to an influenza pandemic or other emerging zoonotic disease by using pandemic (H1N1) 2009 as a case study. The meeting was convened by the US Department of Homeland Security National Center for Foreign Animal and Zoonotic Disease Defense, and the National Institute of Allergy and Infectious Diseases/National Institutes of Health Western Regional Center of Excellence for Biodefense and Emerging Infectious Diseases.
The One Health concept is the realization that human, animal, and environmental health are interrelated. In practice, it is imperative to implement a One Health approach to high-consequence zoonotic diseases. Although pandemic (H1N1) 2009 virus has primarily affected humans (with some documented human-to-animal transmission), the genesis of this circulating human virus involved reassortment of viral genomic segments from human, porcine, and avian influenza virus lineages. The task force focused on 4 topics: 1) epidemiology and surveillance, 2) transmission dynamics, 3) immunobiology and vaccines, and 4) molecular approaches and pathobiology.
Epidemiology and Surveillance
A clear consensus that emerged from the task force was that current surveillance capabilities should be expanded and improved in a scientifically rational and sustainable fashion. Enhanced surveillance may be accomplished through several means, including establishing new field investigational programs and bolstering existing national and global surveillance networks, particularly at the animal–human interface. Because epidemiologic investigation is increasingly dependent on molecular information, modern molecular and informational technologies must be applied to the development of useful field and laboratory deployable devices. These advances will be negated unless they are coordinated with efficient global reporting and sample submission schemes that can aggregate and analyze accumulating data for identification of interrelationships among influenza viruses and hosts. The task force recognized and endorsed the broader, yet parallel, recommendations made by the Institute of Medicine/National Research Council in its report, Sustaining Global Surveillance and Response to Emerging Zoonotic Diseases (www.nap.edu/catalog.php?record_id=12625).
The measurement, understanding, and transmission control of influenza viruses between and among species and the environment is one of the most difficult topics to address. Influenza viruses represent a constantly evolving genetic pool of material in multiple species. Given the mutation and reassortment capability of influenza virus, the number of potential influenza virus strains functionally approaches infinity and raises the question of why history has not documented more influenza pandemics. Development of a pandemic state is a function of virus replication competence and a receptive and immunologically naive host population. The task force concluded that new genetic markers need to be identified in virus and host to clarify and potentially interrupt the transmission process. However, we currently lack sufficient genetic information on influenza virus host determinants to develop reliable and predictable genetic markers. Expanding our knowledge requires complete sequencing and fine mapping of all genomic segments of critical influenza virus isolates. This knowledge includes genetic sequencing of influenza viruses found among wildlife and domesticated animals, which are often neglected.
Immunobiology and Vaccines
One of the largest gaps found in preparedness for pandemic (H1N1) 2009 was the inability of scientists to translate virus detection and characterization into effective vaccines in an efficient and timely manner. Many of these issues similarly limit development of seasonal human and animal influenza vaccines. The task force believes that the most effective way to combat these challenges is by improving vaccine technology and production. Such improvements would include transitioning from using the outdated technique of growing vaccine in eggs to using cell culture and reverse genetic technologies.
Addition of adjuvants to influenza vaccines has been approved in many countries outside the United States. Approval of these adjuvants by the US Food and Drug Administration will help decrease the amount of vaccine needed per dose and concurrently enhance immunity. Increased collaboration between the 2 regulatory agencies involved in vaccine licensure (Food and Drug Administration and Department of Agriculture) provides opportunities for streamlined vaccine development and adoption of new technologies. To expedite this process, better understanding of protection, including cell-mediated immunity, and the role of heterologous immunity for different vaccine strains is needed. Faster delivery methods and more effective distribution will alleviate problems faced by the general public in receiving pandemic (H1N1) 2009 vaccination.
Molecular Approaches and Pathobiology
Understanding underlying mechanisms at the molecular level is critical. Emerging developments in “-omics” tools, including but not limited to genomics, transcriptomics, proteomics, epigenetics, and bioinformatics for host and pathogen, should provide understanding at fundamental levels of how a lethal virus evolves and how its transmission and spread might be stopped. The task force concluded that these new developments must be used to predict, prepare for, prevent, and mitigate the future emergence of high-consequence influenza or other zoonotic diseases. New fields in molecular biology will provide needed information regarding influenza epidemiology, genetics, genomics, and transcriptomics, and aid in understanding genetic host factors that affect resistance, virulence, and immune response.
In examining the 4 themes, the task force discovered several cross-cutting challenges. One challenge was the development of universal recognition of the concept, with a common definition, of One Health across the fields of animal and human health. Although widely embraced within veterinary medicine, this concept needs further integration into medical schools and clinical and research settings. Another challenge was in fostering multiagency collaboration between animal health and public health workers and federal and state agencies.
Ensuring accurate communication between health entities, the media, and general public is another major challenge. Widespread use of the term swine flu during pandemic (H1N1) 2009 devastated the US pork industry because of consumer fears and bans by foreign trading partners.
Perhaps the biggest challenge was in preparing for the unpredictable. It is impossible to determine specifically where and when the next influenza pandemic will emerge or its severity. Despite these unknowns, we can prepare for an influenza pandemic or another zoonotic disease through enhanced surveillance and extensive response planning.
Pandemic (H1N1) 2009 was a test case for future pandemics. The challenge now will be to truly implement a One Health approach in addressing the knowledge gap in preparing for and responding to future influenza pandemics or zoonotic diseases.
Dr Powdrill is assistant director for external affairs and biological systems theme leader at the National Center for Foreign Animal and Zoonotic Disease Defense Center at Texas A&M University. His research interests include basic research leading to the development of countermeasures for high-consequence foreign animal and zoonotic diseases.
Suggested citation for this article: Powdrill TF, Nipp TL, Rinderknecht JL. One health approach to influenza: assessment of critical issues and options [conference summary]. Emerg Infect Dis [serial on the Internet]. 2010 Aug [date cited]. http://wwwnc.cdc.gov/eid/article/16/8/10-0673.htm
1A copy of the full report may be accessed at http://fazd.tamu.edu/ITFreport.pdf.
1Meeting participants: Rusty Cawley, Neville Clarke, Terry Nipp, Thomas Powdrill, Jennifer Rinderknecht, Gary Snowder (Texas A&M University, College Station, Texas, USA); Nancy Cox, Sherif Zaki (Centers for Disease Control and Prevention, Atlanta, Georgia, USA); Yuriy Fofanov (University of Houston, Houston, Texas, USA); Marie Gramer (University of Minnesota, St. Paul, Minnesota, USA); Hon Ip (US Geological Survey, Madison, Wisconsin, USA); Marcus Kehrli, Elizabeth Lautner (US Department of Agriculture, Ames, Iowa, USA); George Korch, Gerald Parker (US Department of Health and Human Services, Washington, DC, USA); Tom Ksiazek, Frederick Murphy, Richard Pyles, David Walker (University of Texas Medical Branch, Galveston, Texas, USA); Mark Miller (National Institutes of Health, Bethesda, Maryland, USA); Christopher Olsen (University of Wisconsin, Madison, Wisconsin, USA); Marguerite Pappaioanou (American Association of Veterinary Medical Colleges, Washington, DC); Daniel Perez (University of Maryland, College Park, Maryland, USA); and Richard Slemons (Ohio State University, Columbus, Ohio, USA).