Russian leader Vladimir Putin has been accused of a cover-up after the death of a worker at a plague research lab in Siberia, as the Daily Star reported this week.
There are fears of a leak and that it may linked to experiments with plague infested squirrels to turn the Black Death disease into a bio-weapon, but Russian officials deny there was even an accident.
So just what is the plague? Here, James Moore has put together the ultimate Q and A with everything you need to know…
What’s happened? Daria Shipilova, 28, fell ill after apparently dropping and breaking a test tube containing plague bacteria at a lab.
She died from pneumonia of “unknown origin” three days later. Other workers have been quarantined. Russian authorities maintain there’s no outbreak, but there are worries the plague could spread.
What is the plague? It’s an infectious disease caused by a bacterium called Yersinia pestis.
There are three forms. Bubonic, the most common, affects the lymph nodes. Septicaemic affects the blood. The rarer pneumonic plague is the type in question in this incident. It’s the deadliest and affects the lungs.
What are the symptoms of pneumonic plague? Shortness of breath, chest pain, fever and coughing up blood. The symptoms usually come on within 24 hours.
What’s the mortality rate? Nearly always fatal unless treated with antibiotics.
How’s it spread? Bubonic plague is usually spread to humans through flea bites.
Pneumonic plague is typically spread by breathing in droplets of infected air from a human or animal. But it needs close contact to spread and is less infectious than Covid, for example.
Is there a vaccine? There are vaccines, but they’re not often used and aren’t reckoned to be very effective in preventing pneumonic plague.
Did it cause the Black Death? Boffins think pneumonic plague was responsible for most of the 50million Black Death fatalities across Europe in the 14 th century.
How common is plague now? There are about 2000 human cases worldwide annually, mostly in Africa. It’s often found in rodents, including squirrels and their fleas.
Has plague been used in war? In 1347 Mongol forces wreaked havoc by flinging plague infested corpses into the besieged Crimean city of Caffa.
In the 1940s Japanese forces dropped plague infected fleas over China, killing thousands.
Both the Soviet Union and the US experimented with weaponizing plague in the early Cold War, while the secret Operation Cauldron in 1952 saw British plague tests carried out on animals off the coast of Scotland.
Experts say the pneumonic plague does have the potential to be weaponized.
What’s your risk? There’s little chance of a plague epidemic according to the World Health Organisation and the UK Health Security Agency says the risk to the British population is currently very low.