A Russian lab technician has died at a plague research centre in Siberia, but there are many reasons pneumonic plague is usually easily contained.
It may seem eerily familiar.
On Friday last week, a woman died from pneumonia of “undetermined” origin in Siberia after potentially being exposed to the plague. Russian media have reported that nearly 200 people were placed in isolation. Officials quickly shut down concern, but online speculation and alarm have been spreading.
The 28-year-old woman, named Darya Shipilova, worked at the Anti-Plague Institute in Siberia’s Irkutsk region. Unconfirmed reports suggested the woman fell ill with pneumonia-like symptoms either after breaking a test tube containing the plague bacterium, or following a field trip to the Buryatia region on the border with Mongolia. In this area, plague is endemic among wild animals.
As of this date no cause of death has been officially confirmed for Shipilova and laboratory testing is reportedly underway. But one thing is clear. Experts say that the case is unlikely to lead to a global outbreak. Here’s why.
The plague is caused by the bacterium Yersinia pestis. Clinically there are three forms: bubonic plague, pneumonic plague and septicaemic plague.
The bubonic plague is the most common variant and is spread by the bites of infected fleas. Once inside a human host, the bacterium travels to the lymph nodes where it causes painful sores called ‘buboes’ in the groin, neck and armpits. Human-to-human transmission of bubonic plague is rare, but the bacterium can spread to the blood where it causes septicaemic plague, or the lungs, causing pneumonic plague.
Unlike the other forms of plague, the pneumonic version can pass from person to person via tiny droplets released into the air when a person coughs or sneezes. Pneumonic plague is also usually fatal unless treated early, and the time from exposure to when symptoms begin can be as short as 24 hours.
The Black Death, caused by bubonic and pneumonic plague, killed more than 25 million people in Europe in the 14th Century, wiping out between one third to two thirds of the population. It was made possible by newly opened trade routes, and the importing of goods such as grain and flour via ships.
