Russian lab worker dies of suspected plague. This is what you should know

Russian scientists and hospital patients are in quarantine after a laboratory researcher has died from suspected plague, amid reports she caught the illness from her workplace. The plague bacterium has high fatality rates if untreated – in the past it caused deadly epidemics throughout the world, including the “Black Death” of the 1300s, which killed half of Europe. While Russian citizens in Irkutsk and the wider Siberian region have been wearing masks and cancelling travel, UK experts have said there is no reason to expect global spread. Here’s what we do and don’t know. Shorts Could this cause a new pandemic? It’s extremely unlikely, because conditions are very different today from when the Black Death stalked the Earth. Then, the disease was mainly caused by bites from fleas living on infected rats, which in wealthy countries like the UK people rarely get close to. That hard-to-spread form of the disease is called bubonic plague. But if untreated, it can reach the lungs to cause pneumonia, which can then spread through droplets in the air between people in close contact. The suspected victim in Russia, Darya Shipilova, a 28-year-old laboratory technician at the Irkutsk Anti-Plague Institute of Siberia and the Far East, died from pneumonia. This suggests she had pneumonic plague, hence the quarantining of her contacts. But even if a few people did catch it from her, modern medicine means we could stop the outbreak from spreading further. For all its fearsome reputation, the plague bacterium, Yersinia pestis, can be treated and prevented with simple antibiotics. “There aren’t as many rats about today and people are a lot healthier and cleaner than they were,” said Dr Simon Clarke, microbiologist at the University of Reading. The infectious diseases hospital in Shelekhov, Irkutsk, has been placed under quarantine following the lab technician’s death from pneumonia (Photo: Reuters) Could this be a mutated version of the plague? There is speculation online that the bacterium that killed Shipilova could have been genetically tweaked to be deadlier or more transmissible. Some strains of the plague are resistant to some antibiotics, but there is no reason to think this is the case here – and many antibiotics work against the plague. It also seems unlikely that the Russian government would deliberately create a deadly version of the plague even to use against its worst enemies. The Covid pandemic showed that infectious diseases have no respect for international borders, and so Russian citizens would be just as likely to succumb. Was this a lab leak? Shipilova’s job certainly makes it a possibility, and there are reports that she told doctors she had broken a test-tube at work. But other researchers say this sounds implausible. Labs studying dangerous pathogens usually employ several layers of protection, such as researchers wearing gloves and masks and handling containers of the bugs inside cabinets with ventilation systems, said Clarke. “We also don’t tend to use test-tubes very much.” Another possibility is that Shipilova caught the infection from wild animals. Plague bacteria are naturally present in many species of small rodents, such as marmots, in that part of Russia as well as Africa, Asia and the Americas. How sure are we that she had the plague? That’s uncertain. The latest statements from Russian authorities say that Shipilova’s pneumonia was of unknown origin. However, “given the potential exposure risk, then the screening and quarantining potential contacts appears proportionate”, said Dr Malick Gibani, vaccinologist at Imperial College London. Lab workers at the Russian medical institute where the victim worked (Photo: The Irkutsk Anti-Plague Research Institute of Siberia and Far East/AP) How long before we know if it is spreading? Pneumonic plague has a short incubation period of one to three days. Shipilova was admitted to hospital on 29 September and died on 2 October, so if anyone had caught the infection from her, they should have started showing symptoms by now. The good news is that so far, no one else seems to have become sick, suggesting this is not the start of a wider outbreak. Have there been lab leaks before? In 2009, a biology professor at the University of Chicago called Malcolm Casadaban died after being exposed to the plague bacterium in his lab. Researchers have also been exposed to polio, Ebola and Zika virus – although none of these incidents led to wider outbreaks in the community. The global Covid pandemic may have started after a leak from the Wuhan Institute of Virology, which was studying coronaviruses – a claim denied by the laboratory. The other main idea is that it passed from animal hosts to humans at a large food market. At this stage, we may never find out which theory is right. Is it time to panic? Most experts say this isolated Russian case is not something to worry about. The bacterium doesn’t spread easily through the air, like Covid or flu, only through close face-to-face contact, when people are coughing and sneezing. Plus, there are good supplies of antibiotics that can treat it. “The public health risk from plague to the wider UK population currently remains very low,” said Chris Lewis, director of global health protection at UK Health Security Agency. “We are seeking information through the international health regulations channels to further understand the circumstances and verify the accuracy of these reports.”