American scientists have issued a stark warning about two emerging animal-borne viruses that could represent the next significant public health threats to families across the United States. In a newly published review, researchers highlight the influenza D virus and canine coronavirus as pathogens currently flying under the radar but possessing concerning potential for wider human transmission.
Underestimated Threats with Pandemic Potential
Dr. John Lednicky, a research professor at the University of Florida College of Public Health and Health Professions, emphasised the gravity of the situation in an official statement. "Our review of the literature indicates these two viruses pose respiratory disease threats to humans, yet little has been done to respond to or prevent infection from these viruses," he explained. "If these viruses evolve the capacity to easily transmit person to person, they may be able to cause epidemics or pandemics since most people won't have immunity to them."
Influenza D Virus: From Livestock to Human Concern
First identified in 2011, the influenza D virus has primarily been associated with infections in agricultural animals including pigs, cows, and livestock. Documented cases have also appeared in more diverse species including deer, giraffes, and kangaroos. The virus is believed to contribute significantly to bovine respiratory disease, which represents the most common and costly ailment affecting North America's beef cattle industry with estimated annual losses reaching $1 billion.
Symptoms in infected cattle typically include respiratory distress, nasal discharge, fever, and persistent coughing according to agricultural research bodies. Previous studies examining cattle workers in Colorado and Florida revealed that up to 97 percent carried protective antibodies against influenza D virus, indicating widespread occupational exposure.
While these exposures haven't yet resulted in symptomatic illness among workers, scientists express concern about the virus's evolutionary trajectory. Notably, a strain identified in China has already demonstrated capacity for human-to-human transmission. The absence of routine testing for this virus in the United States means its current impact remains largely unknown and unmonitored.
Canine Coronavirus: Already Crossing Continents
Canine coronavirus, distinct from the SARS-CoV-2 virus responsible for the COVID-19 pandemic, has been associated with serious human infections across multiple continents. Documented cases include pneumonia hospitalisations throughout Southeast Asia and a 2017 incident involving a traveler from Florida to Haiti who experienced fever and significant discomfort.
The same viral strain identified in that traveler was subsequently found in a hospitalised child in Malaysia and has been detected in individuals with respiratory illness living in Thailand, Vietnam, and notably in Arkansas during 2010. This geographical spread demonstrates that the virus is already circulating internationally, with the U.S. Food and Drug Administration acknowledging its presence across multiple continents.
Urgent Calls for Enhanced Preparedness
The research team asserts that both viruses possess genuine potential to trigger significant outbreaks and requires immediate attention from public health authorities. They advocate for substantial improvements in several critical areas including enhanced viral surveillance systems, development of more reliable diagnostic testing, and increased investment in potential treatments and preventive vaccines.
"Our knowledge about the viruses' epidemiology and clinical manifestations are limited to a modest number of research studies," the authors acknowledged in their publication. "Even so, the limited data regarding these novel, newly detected viruses indicate that they are a major threat to public health."
Context of Ongoing Viral Threats
This warning emerges against the backdrop of continuing H5N1 avian influenza outbreaks affecting commercial poultry flocks and wild birds across the United States. Recent data from the U.S. Department of Agriculture indicates increased bird infections this month compared to December figures. Last year's H5N1 spread resulted in dramatic egg price increases and widespread milk testing initiatives nationwide.
Experts have consistently warned that avian influenza represents another pathogen that could eventually mutate to enable efficient human-to-human transmission, though this adaptation hasn't yet occurred. "If it continues to be widely circulating in poultry, mammals and humans, it may certainly one day evolve into something very serious," cautioned Kelvin To, a clinical microbiologist at the University of Hong Kong, in recent commentary.
The convergence of these multiple zoonotic threats underscores the pressing need for robust surveillance systems and proactive public health strategies to address viruses emerging from animal populations before they escalate into full-scale public health emergencies.
