A 28-year-old technician at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East in Russia died from pneumonia last week, prompting fresh questions about pneumonic plague. Health authorities have not identified an official cause of death. According to the World Health Organization, none of the woman’s close contacts have tested positive for plague and the global public health risk is considered low.
Conflicting accounts have circulated in Russia about how the employee, identified by local reports as Darya Shipilova, became ill. One report suggested exposure from a broken test tube containing plague samples, while another pointed to a recent trip to Thailand. Unverified claims that she worked in a bioterrorism unit have also emerged. Dozens of people in Siberia are under quarantine, officials said, but no linked infections have been confirmed.
A microbiologist at Tulane University noted in separate media interviews that the death could ultimately prove unrelated to her workplace, and that the timing may be coincidental. The WHO said it is working with Russian health authorities as the investigation continues.
What is pneumonic plague?
Plague is caused by the bacterium Yersinia pestis. The Centers for Disease Control and Prevention describes three main forms: bubonic, septicemic, and pneumonic. Pneumonic plague is the most severe and the only form that can spread from person to person, though it is the least common in nature.
Pneumonic plague can develop when Y. pestis reaches the lungs during untreated bubonic or septicemic infection, or when a person inhales respiratory droplets from an infected person or animal. Symptoms include fever, headache, weakness, and rapidly developing pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery sputum. The World Health Organization notes symptoms can begin within a day of infection, and without prompt care, death can occur within 18 to 24 hours.
Experts cite the infection’s speed and lethality as reasons it is listed by the CDC as a Category A bioterrorism agent.
How is it treated?
Physicians can treat plague with antibiotics, typically for about two weeks, and early treatment is critical. Supportive care can include supplemental oxygen, fluids, and rest. If untreated, pneumonic plague is almost always fatal. A vaccine exists, but routine vaccination is not recommended by the CDC or WHO for the general public. It is considered for people at high occupational risk, such as laboratory personnel who work with Y. pestis.
Quick fact: The Black Death
The Black Death was a plague pandemic that killed an estimated 25 million people in Europe between 1347 and 1351.
Should you be worried about pneumonic plague?
Public health experts say the case does not warrant undue alarm, while acknowledging the need for more information. Sporadic plague infections occur globally, including in the United States, where the CDC reports about seven cases annually, mostly in the Southwest where flea hosts of Y. pestis are established.
According to the WHO, the risk of pneumonic plague transmission is moderate to low within the Irkutsk region and low elsewhere. The agency said it will continue to coordinate with Russian authorities as they assess the situation.