Teen Bat Viruses: Causes & Concerns
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New research reveals high rates of coronavirus co-infection in young bats, providing a potential model for understanding the emergence of novel viruses.
Coronaviruses, a family of viruses endemic in bat populations worldwide, rarely infect humans. However, when they do, as seen in the SARS, COVID-19, and MERS outbreaks, they typically spill over from bats through an intermediary animal host. Understanding the natural circulation and evolution of thes viruses within bat populations is crucial for predicting and mitigating future pandemic threats.
A complete study led by Dr. Alison Peel from the University’s School of Veterinary Science has shed new light on coronavirus dynamics in Australian flying foxes. The research, which collected over 2,500 fecal samples from black flying foxes and gray-headed flying foxes across the eastern seaboard over three years, identified a notable prevalence of coronaviruses, notably in young bats.
The study found that coronaviruses were most prevalent in juvenile and subadult bats between March and July, a period coinciding with weaning and the approach of maturity. This consistent pattern across the three-year study period highlights a critical window for viral transmission and potential evolution.
“We were surprised by that high rate of co-infection among juveniles and subadults,” stated Dr. Peel. “Co-infection presents the prospect for a single cell to become infected with multiple viruses, an significant natural precursor to the generation of new strains.”
The research detected six coronaviruses, all belonging to the nobecovirus subclass, which dose not typically infect humans. Three of these were newly identified. While posing minimal risk to people, these nobecoviruses are evolutionary cousins of sarbecoviruses – the SARS-like viruses more prone to cross-species transmission. Analyzing the evolution of nobecoviruses,therefore,offers valuable parallel insights into the evolutionary pathways of more hazardous coronaviruses.
“We safely tracked how and when coronaviruses circulated naturally in bat populations, using genomics to track infections to individual animals,” explained Dr. John-Sebastian Eden, a study co-author from the Westmead Institute for Medical Research and the University’s Faculty of Medicine and Health.The findings provide a robust model for scientists globally aiming to understand coronavirus emergence and future risks in bat populations. By focusing on co-infections in young bats during specific periods, researchers may be able to better predict the natural evolution and emergence of riskier coronaviruses before they pose a threat to human health.
Factors Influencing Susceptibility
Dr. Peel emphasized the need for further research to pinpoint why young bats are more susceptible to infection and co-infection. Potential factors include the developmental stage of their immune systems as they transition from maternal care, or the physiological stress associated with seeking a mate for the first time.
Environmental changes also play a significant role. “We certainly know from previous research on other viruses that habitat loss caused by encroaching human populations and food shortages can create stress in bats that weakens immunity and makes them susceptible to infections,” dr. Peel noted. “It will be critically importent to find out if that’s also the case for coronaviruses.”
The research,initiated in 2020 amidst the COVID-19 pandemic,builds upon earlier work on the spread of the Hendra virus,another bat-borne pathogen.
“It’s rare to see this scale and depth of data in virological research, even among human viruses,” Dr. Peel concluded. “The gathering of samples from both individual bats and beneath roosts, and the tracking of individual strains across multiple sites and years, provides a strong foundation for ongoing research into the role of environmental stress on coronavirus emergence.”