Khaberni - A team of infectious disease experts warned that Influenza D virus (an animal virus affecting livestock) and the canine-transmitted coronavirus, both emerging pathogens of animal origin, could pose an increasing threat to public health in the context of weak health surveillance systems and delayed diagnostics, creating conditions favorable for their spread among humans.
This warning came in a study published in the journal Emerging Infectious Diseases, where the researchers pointed out that these two viruses possess evolutionary traits that could enable them to adapt to humans and cause epidemic outbreaks if early preventive measures are not taken.
Experts: Respiratory Threats in the Absence of Preparedness
John Lednicky, a research professor in the Department of Environmental and Global Health at the College of Public Health and Health Professions at the University of Florida, explained that a review of available scientific literature indicates that the Influenza D virus and the canine-transmitted coronavirus represent potential respiratory disease threats to humans, despite limited health responses to detect or prevent their transmission.
He noted that the risk lies in the potential for these viruses to develop the ability to effectively transmit from one human to another, which could lead to epidemics or pandemics, given the lack of prior immunity in most populations.
Influenza D Virus: Extensive Animal Spread
Since the discovery of the Influenza D virus in 2011, this virus has been associated with infections in cattle and pigs, and has later been detected in other animals, including poultry, deer, giraffes, and kangaroos. It is believed to contribute to respiratory diseases in cattle, which costs the livestock industry in the United States about a billion dollars annually.
Studies conducted on cattle farm workers in Colorado and Florida have shown that up to 97 percent of them carry antibodies against the Influenza D virus, indicating their previous exposure to the virus. So far, these infections are classified as "subclinical," meaning without apparent disease symptoms, but scientists warn that the virus has a high potential for rapid evolution.
In this context, the researchers pointed out that a recent strain of the Influenza D virus, isolated in China, has acquired the ability to transmit from human to human.
Documented Human Infections
Conversely, Lednicky confirmed that the canine-transmitted coronavirus has been linked to documented human infections, some of which were described as severe, while diagnostic tests for the virus are not routinely conducted, making the true extent of its spread among the population unknown.
Researchers note that this virus typically causes gastrointestinal diseases in dogs, and it differs from the SARS-CoV-2 virus that causes COVID-19. However, rare human infections associated with it have been recorded, and in some cases, have led to hospital admissions due to pneumonia in several Southeast Asian countries.
New Strains and Transcontinental Spread
In a 2021 study, a team from the University of Florida isolated a strain of canine-transmitted coronavirus from a medical staff member who had traveled from Florida to Haiti in 2017 and later experienced mild fever and general malaise. This strain was named HuCCoV_Z19Haiti.
In the same year, another scientific team, led by Gregory Gray, director of the "One Health" research and training lab at the University of Texas Medical Branch, announced the discovery of a new strain named CCoV-HuPn-2018, isolated from a child admitted to the hospital in Malaysia, which was found to be nearly identical to the strain discovered by the University of Florida team.
Since then, this strain has been detected in people with respiratory diseases in Thailand, Vietnam, and in the state of Arkansas in the United States, indicating that the virus is now spreading across continents.
Calls for Enhanced Surveillance and Preparedness
Researchers believe that these developments serve as a reminder of lessons from previous pandemics, indicating that a virus of animal origin that gains the ability to transmit efficiently among humans can rapidly transform into a widespread pandemic in the absence of preparedness.
Scientists have called for the enhancement of virus monitoring programs, the development of more accurate diagnostic tests, and efforts to provide treatments, and possibly future vaccines.
Researchers note that current knowledge on the epidemiology of these viruses "i.e., how they spread among humans" and their clinical manifestations "i.e., the symptoms they cause" remains limited, but the available data suggest that they pose a significant threat to public health.
