Experts have revealed locations of global ‘hot spots’ where new deadly coronaviruses could emerge, driven by global land-use changes by people – including in China, France and the UK.
Forest fragmentation, agricultural expansion and ranching are all bringing people into closer contact with horseshoe bats, which are known to transmit zoonotic diseases, including Covid-19.
Conditions are “ripe” for disease to spread from bats to humans, especially in China, where a growing demand for meat products has spurred the expansion of large-scale industrial livestock farming.
Concentrated livestock farming is of concern because it brings together large populations of genetically similar, often immune-suppressed animals that are highly vulnerable to disease outbreaks, the researchers said.
The other major global hotspots outside of China are found in Java, Bhutan, Eastern Nepal, Northern Bangladesh, Kerala State (India), and Northeast India.
While there are also low-risk “cold spots” in southern China, the analysis also found that parts of the country south of Shanghai, as well as Japan and the northern Philippines, are at risk of becoming hot spots with further forest fragmentation.
Meanwhile, parts of mainland Southeast Asia (Indochina) and Thailand may turn into hotspots with an increase in livestock, they reveal.
China has the largest hotspot (red) for the confluence of high forest fragmentation, livestock density and human presence in the analysis. There are also high-risk ‘hotspots’ in the UK and France, and low-risk ‘cold spots’ in southern China and the Middle East
Hotspots (red) and ‘coldspots’ (blue) of forest fragmentation, from the British Isles to Southeast Asia. On average, China shows greater forest fragmentation (stakes) than the other regions analyzed geanalyseerd
DOES COVID-19 COMING OUT OF A WUHAN LAB?
British intelligence now believes it is “feasible” that the coronavirus pandemic started with a leak from a research lab in Wuhan.
They are now investigating the possibility that a leak from the Wuhan Institute of Virology, a Chinese research facility, triggered the global crisis that resulted in more than 3.5 million deaths.
Western intelligence agencies had seemingly written off the “external” chance that the lab — which researches bat-derived coronaviruses — had played a role, but a recent reassessment has led to the leak theory being deemed “feasible,” sources say.
Read more: Leak theory in Wuhan lab ‘is feasible’, says British intelligence
The study was conducted by researchers from the University of California, Berkeley, Polytechnic University of Milan and Massey University of New Zealand.
They used remote sensing to analyze land use patterns across the horseshoe bat’s range, which stretches from Western Europe to Southeast Asia, although it’s rare in the UK.
The team identified areas of forest fragmentation, human settlement, and agricultural and ranching, which they compared to known habitats for horseshoe bats.
This allowed them to find potential hot spots where the habitat is favorable for these bat species in the horseshoe family (Rhinolophidae), and where zoonotic viruses could jump from bats to humans.
“The analyzes aimed to identify the possible emergence of new hotspots in response to an increase in one of three land use characteristics,” said study co-author Maria Cristina Rulli of the Polytechnic University of Milan.
‘[We’re] highlighting both the areas that could become suitable for overflow and the type of land use change that could trigger hot spot activation.
“We hope these results can be useful for identifying region-specific targeted interventions needed to increase resilience to coronavirus spillover.”
A 2017 study the researchers previously linked forest fragmentation and habitat destruction in Africa to outbreaks of the Ebola virus.
Forest fragmentation, agricultural expansion and ranching all put people in closer contact with horseshoe bats (pictured) that carry zoonotic diseases
The exact origin of SARS-CoV-2, the virus that causes Covid-19, remains unclear – and may never be officially confirmed.
A recently surfaced theory – which leaked from a lab in Wuhan at the end of 2019 – is “feasible” according to British intelligence.
The most popular theory among scientists is that it emerged when a virus that infected horseshoe bats was able to jump on humans.
This was done either directly through animal-human contact, or indirectly by first infecting an intermediate host, such as the pangolin – a scaly mammal often confused with a reptile.
Horseshoe bats are known to carry a variety of coronaviruses, including strains that are genetically similar to those that cause Covid-19 and severe acute respiratory syndrome (SARS).
SARS-CoV-2 likely has its ancestral origin in a bat species, but may have reached humans through an intermediate species, such as pangolins — a scaly mammal often confused with a reptile (pictured)
Horseshoe bats are a generalist species and have often been observed in areas characterized by human disturbance.
“Land-use changes can have a significant impact on human health, both because we change the environment, but also because they can increase our exposure to zoonotic diseases,” said study author Paolo D’Odorico, a professor of environmental science, policy and management at UC Berkeley.
“Any formal land-use change must be assessed not only for its ecological and social impacts on resources such as carbon stocks, the microclimate and water availability, but also for the potential chain reactions that could affect human health.”
Human degradation of natural habitats may also indirectly increase exposure to zoonotic diseases by reducing biodiversity.
When forest areas become fragmented and natural habitats are destroyed, species that require very specific habitats to survive, called ‘specialists’, can dwindle or even go extinct.
Without competition from specialists, ‘generalistic’ species, which are less choosy about their habitat, can take over.
China has been a leader in tree planting and other greening for the past two decades, but many of the trees have been planted in interrupted land areas or forest fragments.
To tip the ecological balance back in favor of specialized species, creating contiguous areas of forest cover and wildlife corridors is more important than increasing total tree cover.
“Human health is intertwined with the health of the environment and also with the health of animals,” D’Odorico said.
“Our study is one of the first to connect the dots and really dig into the geographic land use data to see how humans interact with species that may be carriers.
“While we cannot directly trace the transmission of SARS-CoV-2 from wildlife to humans, we do know that the type of land-use change that humans are portraying is typically associated with the presence of these bats that are known is that they carry the virus.’
The study is published in Nature Food.
Scientists in China believe SARS-CoV-2 comes from bats
The human COVID-19 SARS-CoV-2 virus split from its closest known relative — another horseshoe bat coronavirus (pictured) — about 30 to 40 years ago, according to Professor Simon Hothe of the University of Sydney, jumped to the human most likely more recently
Researchers from the Chinese Academy of Sciences, the People’s Liberation Army and Institut Pasteur of Shanghai concluded that the coronavirus may have originated from bats.
In a statement, the team said, “The natural host of the Wuhan coronavirus” could be bats… but between bats and humans, there may be an unknown intermediate.
Research published in the Lancet also found that bats were the most likely original host of the virus after samples were taken from the lungs of nine patients in Wuhan.
The team suggested that bats passed the disease on to an “intermediate host” located at the Huanan fish market in Wuhan before passing it on to the “terminal host” — humans.
Authorities have placed the blame on food markets in Wuhan, the Chinese city at the center of the outbreak that scientists are trying to contain.
Rodents and bats, among others, are slaughtered and sold in traditional ‘wet markets’, where tourists flock to see the ‘real’ side of the country.