The death of a researcher in Siberia and the precautionary measures bring attention to an ancient but still present disease. How it is transmitted, what symptoms it causes and why antibiotics can save lives today.
There pneumonic plague has returned to newspapers around the world for a story that begins in Irkutsk, Siberia. On October 3, the governor of neighboring Buryatia wrote on Telegram that a woman had died, perhaps from the plague: she worked in a Russian disease research institute. He was 28 years old. Since then the versions have overlapped, the Russian authorities speak of pneumonia of unknown origin. Regional media mention the plague. The World Health Organization (WHO) says it has been following the case since October 2 and does not yet know the agent that caused the death.
Pneumonic plague in Russia: established facts and hypotheses
The governor, Alexei Tsydenov, had initially written that the woman had died of the plague and then corrected the text with a more prudent “perhaps”. Furthermore, many details come from the Russian media, so it is not clear whether it is really about pneumonic plague. The day after the message the Russian health agency Rospotrebnadzor confirmed the death of the employee of the Irkutsk Institute, claiming that she had pneumonia of unknown etiology, and defined the situation in Irkutsk and Shelekhov as stable: adding that extensive tests would not have identified microorganisms linked to the woman’s work. Then there is the rest, which comes from local sources and is not confirmed: according to the regional media a test tube would have broken in the laboratorywhile the Telegram channel Mash wrote that the woman had fallen ill after a trip to Buryatia, where an outbreak was reported near the border with Mongolia. But neither of the two reconstructions has found official confirmation.
Quarantine numbers are also circulating, because according to the Russian media, almost 200 people are under medical observation and some hospitals are isolatedalthough Moscow, according to Al Jazeera, denies having imposed anti-plague measures. On October 6, a message from the Russian authorities reported by the WHO explained that tests on contacts had not detected pathogens of dangerous diseases, and that the clinical picture initially resembled a common viral respiratory infection. Rumors of a second case arrived on Wednesday 7 October and Kremlin spokesman Dmitry Peskov responded that much of what the media writes is falsewhile the next day Rospotrebnadzor also denied it. Meanwhile, the director general of the WHO, Tedros Adhanom Ghebreyesus, has nevertheless asked Moscow to clarify, given that it is not yet clear how the woman became infected.
Pneumonic plague: how it is transmitted and why it is the most dangerous form
The plague is caused by Yersinia pestisa bacterium that normally lives in small mammals and their fleas, and the bubonic form, the one linked to the Black Death of the fourteenth century, is the best known, but if it is not treated the bacteria can pass into the blood or lungs. It is born in the lungs the pneumonic form, which can develop from bubonic or septicemic plague neglected, or by inhaling infected droplets coughed up by a sick person or animal, ed it is the only variant that passes from human to human via the respiratory route: which is why the WHO considers it particularly contagious and capable of triggering severe epidemics. Incubation can last as little as 24 hours and symptoms usually appear within one to three days, with shortness of breath and cough, often accompanied by bloody or watery catarrh, and without treatment the lethality ranges from 30 to 100%. If antibiotics are promptly administered, however, recovery is frequent. In Europe the plague has been missing for more than fifty years and human cases of pneumonic plague and other forms are recorded today especially in Africa, in particular in the Democratic Republic of Congo and Madagascar, where the rules are known: the patient must be isolated, contacts must be traced and treated, and the vaccine is not recommended for the general population but only for exposed groups, such as laboratory personnel and healthcare workers. British experts urge caution: Brendan Wren, of the London School of Hygiene & Tropical Medicine, recalls that transmission between humans is generally low, although he specified that a case contracted in a laboratory could, in theory, spread through the respiratory route.
The Madagascar precedent: the urban epidemic that was contained
The last major test was in 2017, in Madagascarwhere the epidemic was identified on 11 September after the death of a 47-year-old woman in Antananarivo, hospitalized for respiratory failure due to pneumonic plague, and the WHO was notified two days later. From 1 August to 24 November, 2,384 confirmed, probable and suspected cases were reported, with 207 deaths (9% lethality) in 57 out of 114 districts, and if the country normally records around 400 cases a year, almost always bubonic and rural, in 2017 the cases were at least six times as many and the pneumonic form dominated in the cities, including the capital and the port of Toamasina. Yet the epidemic stopped, thanks to a response based on isolation of patients, antibiotic prophylaxis of contacts and widespread surveillance: only eleven contacts developed symptoms and were classified as suspected cases, 71 healthcare workers were affected as of November 3 without any deaths, and on November 27 the Ministry of Health announced containment. Now for Russia it will be necessary to observe a possible second confirmed case, the definitive diagnosis, the access of independent experts and the regularity of the data provided by Moscow, while the American CDC estimates the risk for the United States extremely low. ECDC reports few trips between Irkutsk and the European Union, and as long as there is a lack of verifiable diagnosis and history any conclusions remain premature. For now, therefore, the Irkutsk case remains suspended between clinical questions and epidemiological prudence. Without verifiable laboratory results, any hypothesis risks ahead of the evidence. The priority is to distinguish facts from rumours, without fueling alarmism or dismissing the matter prematurely. Because, in infectious emergencies, it is the absence of certain answers that makes surveillance indispensable.
