What is Pneumonic Plague Causing Alarm in Russia? How Does it Spread?
The World Health Organization (WHO) has requested that Russia provide further information regarding the death of a worker at a plague research laboratory in Siberia. While it is not yet certain what caused the worker to fall ill, media reports have triggered various speculations. Russian officials are still investigating the cause of death; however, they have stated that all individuals who came into contact with the researcher have tested negative for pneumonic plague.
What is pneumonic plague, and how dangerous is this disease? Pneumonic plague is a very serious lung infection and is often described as the most virulent form of plague. There are two other types of plague: bubonic plague, which affects the lymph nodes, and septicemic plague, which affects the bloodstream. Pneumonic plague can occur after an individual has first been infected by one of the other two types.
Symptoms include shortness of breath, chest pain, and often coughing up blood. Pneumonic plague is considered more serious but occurs less frequently than bubonic plague. The number of cases of the three types of plague worldwide varies annually, but it is estimated to range between 1,000 and 3,000 cases. Most cases are bubonic plague, with many occurring in Central Africa, though plague cases are also found in several other countries, including Russia, India, China, and the United States.
Professor Piero Olliaro, a professor of infectious diseases related to poverty at the University of Oxford, stated that the bacteria causing the plague still persist in various parts of the world. “Plague itself has not disappeared. The causative bacteria, Yersinia pestis, still survives in the animals that serve as its reservoir across the globe,” he said. “Around 200 rodent species can carry the bacteria, with reservoirs found in the Americas, Eurasia, and Africa. Therefore, human cases still occur sporadically. However, available surveillance systems, infection control measures, and effective antibiotic treatments are essential tools for limiting its impact.”
How does pneumonic plague spread? Plague is a communicable disease caused by bacteria usually found in small mammals and the fleas that live on them. A person can become infected through the bite of an infected flea or through contact with infected animals. However, pneumonic plague can also be transmitted between humans through respiratory droplets expelled when a sufferer coughs. These droplets containing the bacteria can then be inhaled by others, although such transmission usually requires sufficiently close contact. Pneumonic plague can also develop in patients with septicemic plague if the infection spreads to the lungs.
Pneumonic plague is believed to have been the primary type of plague behind the outbreak known as the Black Death, which killed millions in Europe during the 14th century. Dr Zania Stamataki, an associate professor of viral immunology at the University of Birmingham, stated that research into diseases such as the plague must continue. “I understand why the presence of plague bacteria in a laboratory could cause concern. Therefore, it is important to explain why such research is conducted. Plague is not merely a disease of the past. It remains endemic in rodent populations in various regions of Africa, Asia, and America. Human cases occur every year, including outbreaks of pneumonic plague. The development of diagnostic methods and vaccines, as well as monitoring antibiotic resistance, all require laboratories that store and study the living organisms that cause the plague. This research is vital to prepare for potential outbreaks.”
Can this disease be treated? According to the World Health Organization (WHO), pneumonic plague has a very short incubation period, sometimes as little as 24 hours. Experts warn that if it is not diagnosed and treated immediately, the disease is almost always fatal. However, plague can be effectively treated with antibiotics if treatment begins early.
Dr Malick Gibani, an associate professor of clinical vaccinology at Imperial College London, stated that this infection is widely regarded as a serious threat to public health. “Pneumonic plague is a very severe form of the disease. Some textbooks suggest mortality rates reach 100% if untreated, although it is difficult to obtain accurate figures nowadays. The disease can be treated with antibiotics, especially if treatment starts early. This is why individuals at high risk of exposure may be given antibiotics as a preventive measure following exposure and/or undergo quarantine.”
In the case in Russia, it remains unclear whether the deceased individual was infected with pneumonic plague. Russian authorities stated that examination results showed “no microorganisms related to the patient’s professional activities were found.” Therefore, it is not yet known exactly what happened. US President Donald Trump stated that Washington is monitoring the case “very seriously,” while the US Centers for Disease Control and Prevention (CDC) stated there is “no indication of a broader threat to the United States.” UK Health and Safety authorities stated they are seeking further information, but the risk to the British public is assessed as “very low.”