Tuesday, 25 June, 2024
HomeEpidemiologyVirus hunters of Sierra Leone pursue the next deadly coronavirus

Virus hunters of Sierra Leone pursue the next deadly coronavirus

A team of medical scientists in Sierra Leon, part of the Predict international network, is in search of a holy grail to virus hunters: the next deadly pathogen that could sweep across the globe, writes The Telegraph.

Gradually, plumes of bats rise like smoke from the caves. Those that get caught in the nets snarl and thrash about. Avoiding their snapping fangs, scientists disentangle the bats and pass them to a team seated around a plastic picnic table converted into a makeshift field laboratory. Under torchlight the bats are weighed and measured, and subjected to oral and rectal swabs, with blood samples taken from the veins laced through their wings. The test tubes are placed in a mobile freezer before the bats are released back into the night air; now carrying the scent of chlorine disinfectant intermingled with rich earth.

The Daily Telegraph reports that by the end of the evening the scientists have tested some 21 bats; insect-eating ones from the Hipposideros genus. The hope, if you can call it that, is that one of them may turn out to be harbouring what is a sort of holy grail to virus hunters: the next deadly pathogen that could sweep across the globe. In July this same team discovered an entirely new strain of the Ebola virus among bats captured in the neighbouring district of Bombali. It is gruelling and potentially lethal work. But the ambition prevails that by locating new diseases in the wild they can prevent epidemics before they spread to humans. ‘

The virus hunters of Sierra Leone are part of an international network known as Predict, launched with $200m funding from the US Agency for International Development (USAID) and currently operating in more than 30 countries. The report says the project has amassed tens of thousands of samples for analysis and discovered more than 900 new viruses.

Predict is a forerunner of the more ambitious Global Virome Project – a 10-year plan to identify as many as possible of the estimated 1.6m unknown viruses in birds and mammals. Of these, it is thought between 600,000 and 800,000 are zoonotic, meaning they have the potential to jump from animals to people. Earlier this year the World Health Organisation (WHO) announced it was sufficiently concerned about what was lurking in the wild to include something called ‘Disease X’ in its global strategy plan, representing an as yet undiscovered pathogen with the potential to spark a pandemic.

Since being established two years ago, the Predict team in Sierra Leone has taken some 49,000 samples from bats, rodents, primates and livestock in more than 30 sites around the country. As well as developing its core team of scientists – who are almost entirely homegrown – the project is also developing a network of 70 trained health officers around the country.

All the domestic-livestock samples taken by the Predict team are analysed in the university city of Makeni, established in partnership with Cambridge University, but those from wild animals are shipped out to the University of California Davis and Columbia University in New York. In July this year, researchers confirmed the discovery of two new viruses in bats in Myanmar. They belong to the coronavirus family, which includes two pathogens already featured in serious outbreaks: severe acute respiratory syndrome (SARS), which spread worldwide in 2003, infecting about 8,000 people; and Middle East Respiratory Syndrome (MERS), first identified in 2012, which has a 35% mortality rate.

The discovery of the Bombali virus in free-tailed bats is the first time a strain of Ebola has been confirmed prior to an outbreak. It is not yet known to what extent it could mutate. “Viruses surprise us all the time,” says Professor Tracey Goldstein, the co-principal lead on pathogen detection for Predict at UC Davis. She points to extrapolated figures that suggest there may be a staggering 3,200 different types of coronavirus harboured in bats alone. “Keeping your eyes on understanding what might be coming up ahead and testing and learning from these viruses once we have found them is critically important.”

Many in rural Africa prefer traditional medicines to those introduced from the West. And, the report says, the local attachment to bushmeat is another challenge that authorities continue to come up against. Sorie Kamara, director of the livestock and veterinary services division at Sierra Leone’s Ministry of Agriculture, describes the consumption of bushmeat as a “serious problem”. The country’s markets were closed during the outbreak but are now once more doing a roaring trade selling tropical game including monkeys, chimpanzees, cane rats, bats and snakes.

Bushmeat is entrenched in local culture and is often a vital form of subsistence, hence why the authorities are unwilling or unable to announce an outright ban. The health risks, however, are enormous.

The report says the HIV/Aids pandemic – which to date has killed 35m and infected 70m – started about a century ago in Cameroon when a chimpanzee virus was transmitted to a human who almost certainly killed, butchered or consumed it. “I am seriously worried for the future, about the diseases lurking in the bush,” says Kamara, sitting in his office in Freetown. “We are making an imbalance in the ecosystem. Ebola caught us unawares, but there may be another far worse threat out there.”

[link url="https://www.telegraph.co.uk/news/disease-x-virus-hunters/?WT.mc_id=e_DM1192958&WT.tsrc=email&etype=Edi_GHS_New_Weekly&utmsource=email&utm_medium=Edi_GHS_New_Weekly20200206&utm_campaign=DM1192958"]Full report in The Daily Telegraph[/link]

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