Researchers have found the first genetic evidence of bat-borne viruses within commercially sold bat guano fertilizer in Thailand.
However, the viral strains the team detected are not known to infect humans. Moreover, since the researchers only identified fragments of viral RNA and did not isolate live, intact viruses, they could not confirm if the genetic material poses an active threat to human health, according to a recent study, reports Mongabay’s Carolyn Cowan.
But the findings suggest that viral genetic material from bat populations can persist far beyond caves and survive within publicly available retail products, the study says.
“The most surprising thing was that these viruses don’t just stay in the caves,” senior author Thachawech Kimprasit, a medical microbiologist at Mahidol University in Bangkok, told Mongabay. “Their material can be found in commercial end products.”
The discovery raises concerns over a general lack of biosecurity protocols to protect harvesters, agricultural workers, and retail handlers, Thachawech added.
Bat guano or droppings are harvested from caves and widely used as agricultural fertilizer around the world. Researchers screened 41 samples of commercially available bat guano fertilizer commonly sold in Thai markets. They found two samples that tested positive for Alphacoronaviruses, a genus of coronaviruses, and one sample that tested positive for Betacoronaviruses, the genus that includes the Sarbecovirus subgenus, from which the pathogen responsible for COVID-19 originates.
The researchers identified the croslet horseshoe bat (Rhinolophus coelophyllus), a cave-dwelling insectivorous species common across mainland Southeast Asia, as the most likely natural host of the detected Betacoronavirus.
“Biosecurity management of bat guano fertilizers might require heat treatment or chemical treatment to remove the virus raw genetic material,” Thachawech said. “We should also focus on maintaining safe ecological boundaries between bats and people.”
Thura Soe Min Htike, a conservation officer at the Nature Conservation Society–Myanmar, who wasn’t involved in the study, said the solution to predicting and preventing zoonotic diseases is not to target bats, but rather to manage human activities.
The mammals provide vital ecological benefits like insect control and crop pollination that have been shown to enhance yields of regional crops like durian, rice and cacao. “The real issue is not the bats themselves, but human disruption of their habitats, which increases the risk of disease transmission,” Thura Soe Min Htike said.
According to Thachawech, the best way to minimize the risk of disease transmission is to follow the “One Health” approach, which recognizes the interconnectedness of human, animal, and environmental health.
“People’s health and environmental health is the same health,” he said. When it comes to bats and their caves, this means minimizing disturbance: “There’s no need to disturb bat roosts.”
Read the full story by Carolyn Cowan here.
Banner image: Bats in a cave roost in Thailand. Image by Jayakarthi Natarajan via Wikimedia Commons (CC BY-SA 4.0).
