Wednesday, November 01, 2017

COCA Call Tomorrow: The Ecology of Emerging Zoonotic Diseases

Zoonotic Virus Transmission


Tomorrow afternoon the CDC will hold a new COCA (Clinician Outreach Communication Activity) call which will focus on the ecology of emerging zoonotic diseases, using Ebola and the Nipah virus as cases studies.
Primarily of interest to clinicians and healthcare providers, COCA calls are designed to ensure that practitioners have up-to-date information for their practices. They can, however, provide important insights to other groups as well.
Zoonotic diseases - those which originated in or are normally hosted by non-human species, but can infect humans - have been with us for thousands of years. Tuberculosis probably jumped to humans when man began to domesticate goats and cattle 5000 years ago. Measles appears to have evolved from canine distemper and/or the Rinderpest virus of cattle.  
And Influenza, as most of you know, is native to aquatic birds.
But the list of zoonotic diseases is long and continues to expand, and includes such notable  nasties as SARS, MERS, Babesiosis, Borrelia (Lyme), Nipah, Hendra, Malaria, Dengue, Zika,  Hantavirus, Ebola, Bartonella, Leptospirosis, Q-Fever, several flavors of avian flu and many, many others.

In 2014, in Emerging zoonotic viral diseases  L.-F. Wang (1, 2) * & G. Crameri wrote:
The last 30 years have seen a rise in emerging infectious diseases in humans and of these over 70% are zoonotic (2, 3). Zoonotic infections are not new. They have always featured among the wide range of human diseases and most, e.g. anthrax, tuberculosis, plague, yellow fever and influenza, have come from domestic animals, poultry and livestock. However, with changes in the environment, human behaviour and habitat, increasingly these infections are emerging from wildlife species.
These emerging infectious diseases are considered such an important threat that the CDC maintains as special division – NCEZID (National Center for Emerging and Zoonotic Infectious Diseases) – to deal with them. 

First, details on tomorrow's presentation (live attendance is limited, but it should be archived on the COCA site within a few days), then I'll return with a bit more.
The Ecology of Emerging Zoonotic Diseases

Date: Thursday, November 2, 2017
Time: 2:00-3:00 pm (Eastern Time)

Participate by webinar (participants will need to register in advance of the call using the link below):
Dial: 1 (415) 655-0052
Access code: 387-065-608
Passcode: Participants will receive passcode once they sign into the webinar


Zoonotic viruses–those which are transmitted between animals and people, represent an important group of pathogens that are responsible for a growing number of significant epidemics. SARS coronavirus, Ebola, Nipah virus, avian influenza, and perhaps most importantly, HIV, are all recently emergent zoonotic viruses that originated in wild animal populations and have caused significant morbidity and mortality in human, and in some cases, animal populations.
Zoonotic viruses can have profound health and economic impacts globally, even when occurring in relatively isolated regions, thereby making them a significant challenge for the global health community. The majority of viral pandemics are triggered by human activities such as deforestation, agricultural expansion and intensification, urbanization, hunting, travel, and wildlife trade.
To be able to minimize the impact of emerging viral zoonoses requires an understanding of the viral diversity within key wildlife reservoirs, the types of human behaviors that increase exposure to an infection with zoonotic viruses, and the ability to rapidly identify the etiologic agent behind clusters of human or domestic animal disease so that effective interventions can be implemented. During this COCA Call, participants will gain a broad understanding of how spillover and disease emergence occurs.
This COCA Call will use Nipah virus and Ebola virus as case studies and discuss effective interventions that reduce the risk of spillover of both known and unknown pathogens from wildlife. We will also discuss efforts that are currently underway to enhance the global community’s capacity to detect and respond to the emergence of novel zoonoses.
         (Continue . .. )

When Steven Soderbergh  made his pandemic thriller `Contagion’ a few years ago, technical adviser Professor Ian Lipkin created the fictional MEV-1 virus based on a mutated Nipah virus (see The Scientific Plausibility of `Contagion’) simply because of the very real possibility of someday seeing a bat-borne pandemic virus.

MERS-Cov, SARS-CoV, and the Ebola viruses (including Marburg) are all believed to originate from bats, and as the links below will attest, they aren't alone.
EID Journal: A New Bat-HKU2–like Coronavirus in Swine, China, 2017

Emerg. Microbes & Infect.: Novel Coronaviruses In Least Horseshoe Bats In Southwestern China

Bat Flu Reassortment Possibilities : Revisited

PNAS: SARS-like WIV1-CoV Poised For Human Emergence

None of this is meant to demonize bats - as they are a crucial part of the ecology - but these winged mammals are increasingly viewed as natural hosts for, and potential vectors of, a number of newly recognized emerging pathogens.

For more on this `golden age' of emerging and re-emerging infectious diseases we seem to find ourselves in, you may also wish to review:
The Third Epidemiological Transition (Revisited)

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