Commentary

ID Blog: Wuhan coronavirus – just a stop on the zoonotic highway


 

Emergent influenzas

The Western world has been most affected by these highly mutable, multispecies zoonotic viruses. The 1957 and 1968 flu pandemics contained a mixture of gene segments from human and avian influenza viruses. “What is clear from genetic analysis of the viruses that caused these past pandemics is that reassortment (gene swapping) occurred to produce novel influenza viruses that caused the pandemics. In both of these cases, the new viruses that emerged showed major differences from the parent viruses,” according to the Centers for Disease Control and Prevention.

Influenza is, however, a good example that all zoonoses are not the result of a mixing-vessel phenomenon, with evidence showing that the origin of the catastrophic 1918 virus pandemic likely resulted from a bird influenza virus directly infecting humans and pigs at about the same time without reassortment, according to the CDC.

Building a protective infrastructure

The first 2 decades of the 21st century saw a huge increase in efforts to develop an infrastructure to monitor and potentially prevent the spread of new zoonoses. As part of a global effort led by the United Nations, the U.S. Agency for International AID developed the PREDICT program in 2009 “to strengthen global capacity for detection and discovery of zoonotic viruses with pandemic potential. Those include coronaviruses, the family to which SARS and MERS belong; paramyxoviruses, like Nipah virus; influenza viruses; and filoviruses, like the ebolavirus.”

PREDICT funding to the EcoHealth Alliance led to discovery of the likely bat origins of the Zaire ebolavirus during the 2013-2016 outbreak. And throughout the existence of PREDICT, more than 145,000 animals and people were surveyed in areas of likely zoonotic outbreaks, leading to the detection of more than “1,100 unique viruses, including zoonotic diseases of public health concern such as Bombali ebolavirus, Zaire ebolavirus, Marburg virus, and MERS- and SARS-like coronaviruses,” according to PREDICT partner, the University of California, Davis.

PREDICT-2 was launched in 2014 with the continuing goals of “identifying and better characterizing pathogens of known epidemic and unknown pandemic potential; recognizing animal reservoirs and amplification hosts of human-infectious viruses; and efficiently targeting intervention action at human behaviors which amplify disease transmission at critical animal-animal and animal-human interfaces in hotspots of viral evolution, spillover, amplification, and spread.”

However, in October 2019, the Trump administration cut all funding to the PREDICT program, leading to its shutdown. In a New York Times interview, Peter Daszak, president of the EcoHealth Alliance, stated: “PREDICT was an approach to heading off pandemics, instead of sitting there waiting for them to emerge and then mobilizing.”

Ultimately, in addition to its human cost, the current Wuhan coronavirus outbreak can be looked at an object lesson – a test of the pandemic surveillance and control systems currently in place, and a practice run for the next and potentially deadlier zoonotic outbreaks to come. Perhaps it is also a reminder that cutting resources to detect zoonoses at their source in their animal hosts – before they enter the human chain– is perhaps not the most prudent of ideas.

mlesney@mdedge.com

Mark Lesney is the managing editor of MDedge.com/IDPractioner. He has a PhD in plant virology and a PhD in the history of science, with a focus on the history of biotechnology and medicine. He has served as an adjunct assistant professor of the department of biochemistry and molecular & celluar biology at Georgetown University, Washington.

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