Six new coronaviruses in bats discovered in Myanmar
Scientists have discovered six new coronaviruses among bats in Myanmar. These coronaviruses are very different from the Severe Acute Respiratory Syndrome (SARS-Cov-1), Middle East Respiratory (MERS) or SARS-CoV-2 which are known to have jumped over from bats and infected humans.
A team of scientists from Smithsonian’s Global Health Program and Conservation Biology Institute said that most of these viruses were found in guano (accumulated faeces) samples harvested by local people in Myanmar for nutrient-rich manure. Whether these new coronaviruses are dangerous for humans is yet to be assessed.
The team focused on sites in Myanmar where humans live in close contact with wildlife like Hlawga National Park in Yangon. From May 2016 to August 2018, the team collected 750 saliva, guano and faecal samples from 11 bat species in these areas. Coronaviruses were detected in 48 samples.
“Guano samples accounted for the majority of positives, suggestive of an important transmission route for CoV shedding from bats and a possible risk to people during the act of guano harvesting,” the study published in PLOS ONE journal on Thursday said, adding that in future viral detection in guano samples can be made through non-invasive methods and doesn’t require people handling bats directly.
“Viral pandemics remind us how closely human health is connected to the health of wildlife and the environment. Worldwide, humans are interacting with wildlife with increasing frequency, so the more we understand about these viruses in animals -- what allows them to mutate and how they spread to other species -- the better we can reduce their pandemic potential,” said Marc Valitutto, a former wildlife veterinarian with the Smithsonian’s Global Health Program and lead author of the study in a statement. Authors also said the ongoing land-use change in Myanmar could be a prominent driver of zoonotic diseases in future.
Despite small sample sizes, the study managed to detect six coronaviruses in insectivorous bats. “Given the potential consequences for public health in light of expanding human activity, continued surveillance for coronaviruses is warranted, especially in other species and human-wildlife interfaces,” the study concluded, adding that over 3,200 CoVs occur in bats, most of which are still undiscovered.
The study said that bats are increasingly being recognised as natural reservoirs of viruses and they have a unique capacity to carry and transmit viruses due to some of their biological traits like the ability of sustained flight, the potential for long-distance dispersal and adaptation to semi-urban habitation. Bats are known to be carriers of the hemorrhagic Ebola, Marburg filovirus and the Nipah virus, apart from viruses that caused SARS, MERS and Covid-19 diseases. But bats are also extremely essential to ecosystems for seed dispersal, pollination, control of insect populations, among others.
Scientists suggest a “One Health” approach to keep zoonotic spillover at bay. One Health, according to the World Health Organization, involves the control of zoonoses, antibiotic resistance, etc., by focusing on the interactions between humans, animals and plants.
“In a country like India, people live cheek by jowl, not just with each other, but also with livestock (including both four-legged and two-legged), as well as in areas of high biodiversity. Such close proximity means that the diversity of pathogens that humans are potentially exposed to is very high. To understand the risks from these pathogens, it is thus necessary for us to adopt a One Health approach, where we have to work in large interdisciplinary teams that can investigate not only human and animal health, but also the links with changes in the natural environment,” said Abi Tamim Vanak, fellow, Wellcome Trust and senior fellow at Ashoka Trust for Research in Ecology and the Environment.
Around 60–75% of emerging infectious diseases consist of zoonotic diseases; more than 70% of those originate in wildlife species.