Could fighting in Sudan result in a deadly lab leak?

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The fighting in Sudan has claimed hundreds of lives and caused many thousands to flee Khartoum as the army clashes with the paramilitary Rapid Support Forces.

Amid the turmoil, the World Health Organisation has in recent days sounded the alarm about the occupation of the capital’s National Public Health Laboratory.

Reports indicate that workers are unable to get into the lab and there are concerns that power cuts could hamper efforts to look after samples.

It raises questions about whether harmful material could be released and pose a risk to nearby populations and highlights the vulnerability of laboratories in countries experiencing conflict.

“If people are in the lab breaking open vials, opening cultures, there’s a risk they could get infected. It’s certainly not safe in that context,” says Paul Hunter, professor of medicine at the University of East Anglia in the UK, who has visited labs in Sudan.

Fortunately, in this instance, the wider threats are thought to be modest. The pathogens that the lab reportedly holds — viruses that cause measles or bacteria that cause cholera, for example — circulate or have recently been circulating in Sudan anyway, according to Prof Hunter.

“If TB got out, there’s plenty of TB already out there,” he says. “If polio got out, Sudan has an ongoing polio virus outbreak. Measles is quite a common infection in that part of the world.

“At the moment, all of the infections that the WHO has said are stored in the lab — viruses or bacteria — are ones that are prevalent in the population anyway.”

A concern would be whether the laboratory has anything more lethal, such as Ebola. This appears, Prof Hunter says, not to be the case. It is a public health laboratory that probably focuses on diagnosis rather than on carrying out research using the most dangerous pathogens.

Sudan, like most other African nations, does not have any laboratories with the highest levels of biosafety. Known as Biosafety Level 4 (BSL-4) facilities, they require considerable investment to set up and run.

Only BSL-4 labs are allowed to deal with deadly microbes easily transmitted by air, and for which there are no effective treatments or vaccines.

The Ebola virus and the Marburg virus, for example, can be worked on only in BSL-4 laboratories, according to the US Centres for Disease Control and Prevention.

In some BSL-4 labs and those with lower levels of biosecurity, “gain of function” research is undertaken, where researchers experiment with pathogens in ways that may make them more of a threat, such as more easily transmitted or more virulent.

Even in developed nations, it can prove difficult to justify the expenditure on BSL-4 facilities, according to a UK House of Commons report, titled Biosecurity in UK Research Laboratories, published in 2008.

An expert quoted in the report stated that level 4 laboratories represent “such a big investment” that a university “would have to have a very serious long-term guaranteed investment” to build one, unless working in conjunction with other universities or agencies. Their high cost limits the number of locations where they can be set up.

That report was produced in response to a 2007 outbreak of foot-and-mouth disease, an often fatal viral condition affecting cloven-hoofed animals including cattle, sheep and pigs. Illustrating the risks that laboratories may pose, this outbreak was traced back to the effluent pipes of either of two research facilities in south-east England.

The origins of the Covid-19 pandemic remain uncertain, but one suggestion is that the novel coronavirus leaked from the Wuhan Institute of Virology in China. The institute has a BSL-4 laboratory, although a senior official at the centre stated that coronavirus work was carried out in BSL-2 and BSL-3 laboratories, which have lower levels of, but still stringent, biosecurity.

It is unlikely to ever be known definitively whether the institute was the source of the pandemic, which WHO figures indicate has killed nearly seven million people. Some researchers believe instead that an animal market in Wuhan was the likely source.

Laboratories in conflict

Laboratories anywhere in the world that deal with potentially dangerous material are typically well run, according to Polly Roy, professor of virology at the London School of Hygiene and Tropical Medicine.

“[They are] well managed generally anywhere in the world. It’s not a threat,” she says. "[There are] very strict biosafety requirements that I’ve seen everywhere. [It is] always extremely difficult for anything to leak out. It’s really managed very strongly.”

There is no official global register of BSL-4 labs, but King’s College London (KCL) and George Mason University (GMU) in the US have found that there are around 60 worldwide.

Of these, three are in Africa — in Ivory Coast, Gabon and South Africa — and one is on the Arabian peninsula, in Riyadh.

The rest are spread across the globe, with particularly large numbers in western Europe, North America, South Asia and East Asia. There are dozens of BSL-3+ facilities, which also work with deadly pathogens.

The Global BioLabs Report 2023 from KCL and GMU recommends that labs adopt an international standard to manage biorisks and calls on the WHO to improve its guidance and to provide a centre in Africa, among other regions, to collaborate with facilities on the continent that handle dangerous material.

“The dangers posed by an accidental or deliberate release of a pandemic-capable pathogen means that strengthening international oversight of high-consequence life sciences is critical,” the report says.

Aside from accidental leaks, experts have highlighted the potential for deliberate biosecurity breaches, such as material being stolen or an employee using insider knowledge for malicious purposes, perhaps even to launch a biological attack.

There are thought to be no BSL-4 or BSL-3+ laboratories in Ukraine, but reports citing an interview on Ukrainian television indicate that the country has two BSL-3 labs, which are said to have multiple biosecurity measures, such as sealed windows and self-closing doors.

Nevertheless, just over a year ago the Reuters news agency reported that the WHO had advised Ukraine to destroy any potentially dangerous pathogens in its laboratories because Russia’s attack on the country could result in material being released.

Any spread of pathogens in a country at war could be especially harmful given that healthcare facilities and disease-control measures would probably be under severe strain.

Also at a time of war there is the risk that populations could be panicked by misinformation, possibly from adversaries, about potential threats from lab leaks.

Often when war breaks out, the greatest — real — threats in terms of disease do not come from lab leaks, but from the collapse of services.

“The big problem in Ukraine is that getting on for two million people no longer have running water”, Prof Hunter said.

“It’s the breakdown of civil society. Another is infrastructure damage, loss of sewerage and drinking water networks — a big issue in Ukraine.”

Forced migration can be another problem, with diseases spreading easily when large numbers of people are in camps in close proximity to one another.

Routine vaccination programmes and other public health campaigns may fall away, causing diseases such as diphtheria to re-emerge.

“This is far more concerning, from a public health perspective, than the lab, but that doesn’t mean we don’t need to worry about the lab,” Prof Hunter says.

The risk of leaks from labs may increase in future because the Covid-19 pandemic has made more countries seek to have their own biosecure laboratories, to improve preparedness for the next major disease outbreak.

Indeed this year’s KCL and GMU report talks of a “global boom in construction of BSL-4 and BSL-3+ labs”, so there may be many more facilities working with the world’s deadliest pathogens in years to come.