Siberia lab death raises pneumonic plague concerns

The death of a laboratory employee in Siberia has raised concerns about a possible outbreak of pneumonic plague, an extremely contagious disease. Russia denies the existence of an outbreak, but the United States is reportedly alarmed. Russian authorities say the 28-year-old woman died from pneumonia of unknown origin, with no plague bacteria found in her samples, contradicting local reports she dropped a test tube. The US is monitoring the situation, with around 200 contacts under supervision and quarantine measures in place. Pneumonic plague is the most aggressive form of the disease, caused by Yersinia pestis and spread through respiratory droplets. Without treatment, it can be fatal within 24 hours, though prompt antibiotic treatment is highly effective.