Bubonic plague is still found in scattered locations around the world, but thanks to modern antibiotics it is far easier to treat than in the past. Yet, the disease may still have left its mark on humankind.
Under the microscope, Yersinia pestis doesn’t look particularly special. It’s a fairly standard shape for a bacterium – a sort of short, round-ended rod – and relatively immobile. But it is responsible for a disease that once wiped out a third of Europe’s population and caused millions of deaths around the world.
The very mention of the words bubonic plague tends to provoke both fear and fascination even today. The disease is now vanishingly rare in both the US and Europe, largely thanks to changes in lifestyles that prevent it from spreading to humans from infected fleas as easily. Even when it does occur, it can be relatively easily treated with antibiotics, saving lives. But cases still do occur.
Most recently, a man in Oregon in the US, caught the bubonic plague from his pet cat. It is not something that comes as an enormous surprise to evolutionary geneticist Paul Norman, who studies bubonic plague at the University of Colorado, Anschutz.