Following the death of a laboratory technician at a plague research institute in the Russian city of Irkutsk, discussion in the media and among the public has intensified over the risk of the infection spreading. Although Russian authorities have denied the reports and cited unspecified pneumonia as the cause of death, the incident has raised a number of questions about laboratory biosafety measures and the potential scale of pathogen transmission.
What risks does plague pose today, how safe are laboratory environments, and is there a threat of a new epidemiological outbreak? Molecular biologist Gvantsa Brachveli discusses these and other important issues with us.
What is plague, and why is it still dangerous today?
Plague is a bacterial infection caused by the bacterium Yersinia pestis. In nature, its main reservoirs are small mammals and their fleas. In humans, the infection is most commonly transmitted through the bite of an infected flea. Human-to-human transmission is also possible, particularly in the case of pneumonic plague, or the pulmonary form, which can spread through respiratory droplets.
It is important to note that an infection caused by the same bacterium can take different clinical forms. The most common is bubonic plague, characterized by painful, enlarged lymph nodes. Pneumonic plague affects the lungs and is particularly important from a public-health perspective because it can be transmitted from person to person. The course and mortality of these forms also differ, with pneumonic plague being especially dangerous if treatment is not started promptly.
Yersinia pestis has, of course, undergone evolution over the centuries, but it is the same bacterium that historically caused major plague epidemics. What has changed radically is our ability to treat and control the disease. Today, we have effective antibiotics, early diagnostic methods, infection-control measures, and epidemiological surveillance systems. Therefore, when the disease is detected and treated promptly, the prognosis is significantly better.
Let us move directly to the incident in Irkutsk — what can be said about the versions circulating about what happened?
First of all, I should point out one important limitation regarding this particular case: independently verified information is quite limited. It is difficult to independently confirm the reports coming from Russian official agencies and media outlets, so at this stage we should distinguish between confirmed facts, the official version, and information reported by the media. Accordingly, based solely on the available reports, we cannot say that the exact mechanism of the laboratory technician’s infection has been established.
In general, however, a laboratory is indeed a high-risk environment, particularly when work involves infectious pathogens. The risk of biological exposure and laboratory-acquired infection can never be reduced to zero. Unfortunately, such incidents can occur even in the best-run laboratories. The main objective is to minimize the risk as much as possible and to have a rapid and effective response system in place in the event of an incident.
Laboratory safety, therefore, is not limited to the use of protective equipment. The qualifications and experience of laboratory personnel and their ability to respond appropriately in high-risk situations are also important. At the same time, the laboratory must be properly equipped, including personal protective equipment, appropriate devices and technology, air-flow and ventilation systems, as well as protocols designed for both routine and emergency situations.
It is equally important that personnel not only know these protocols but also understand how to apply them in practice. There should also be a working environment and safety culture in which employees can immediately report any incident, mistake, or potential hazard without fear of punishment or other negative consequences. In particularly high-risk laboratories, such an open and non-punitive reporting mechanism is critically important, because timely reporting of a minor incident may help prevent a more serious exposure or infection.
Therefore, if a broken test tube is being considered as the official explanation for the Irkutsk incident, knowing only this fact is not enough to assess how plausible a specific infection scenario is. We would need to know what material was in the tube, under what conditions the incident occurred, what protective measures were being used, and whether any biosafety procedures were breached. Without this information, in my view, it would be more appropriate to discuss this as a possible mechanism rather than state that the infection definitely occurred in this way.
There are reports that the young woman was initially considered a COVID-19 patient and was placed on mechanical ventilation without receiving antibiotics. What risks could such a scenario create?
Here, too, we must first distinguish confirmed information from circulating versions of events. At this stage, it has not been independently confirmed that the patient actually had plague, that she was initially diagnosed with COVID-19, or that she did not receive antibiotic therapy. Russian authorities currently state that the patient was diagnosed with pneumonia of unknown etiology and that no microorganism associated with her professional activities was found in her biological material.
However, if we hypothetically assume that the patient did in fact have pneumonic plague, several important issues arise. The clinical picture can overlap to some extent with COVID-19 — both can cause high fever, cough, shortness of breath, and severe pneumonia. According to the CDC, severe viral pneumonia, including COVID-19, can indeed be included in the differential diagnosis of pneumonic plague. However, in this particular case, the epidemiological history would be especially important. If the person actually worked at a plague research institute and, moreover, had genuinely been exposed to material containing Yersinia pestis, this would be highly important information for the treating physician. In such a situation, pneumonic plague should be seriously considered in the differential diagnosis from the outset. According to CDC recommendations, when plague is suspected, treatment should not be delayed while awaiting laboratory results; the decision should be based on the clinical presentation and the patient’s history.
As for ventilation, one important clarification is needed: I would not say that “the ventilator dispersed the pathogen into the air.” That would be an overly direct and, at this stage, unconfirmed formulation. In pneumonic plague, infection can be transmitted from person to person through respiratory particles, particularly during close contact, while intubation and other aerosol-generating procedures may increase the risk of exposure for healthcare workers.
If such a patient was initially not correctly identified and appropriate infection-control measures were not implemented, the main epidemiological risk would be exposure of healthcare workers and other people who had close contact with the patient, potentially resulting in secondary cases. In such a situation, patient isolation, rapid identification and monitoring of contacts, and, where appropriate based on the exposure, preventive antibiotic therapy are essential.
How realistic is the threat of a new global pandemic? Do we have reason to fear that events could unfold in a way similar to the coronavirus pandemic in China, or do modern medicine and antibiotic treatment protect us from such an escalation?
First, we need to distinguish between a theoretical possibility and the actual risk associated with this particular case. At present, the available information does not provide grounds to regard the Irkutsk incident as the beginning of a new global pandemic.
Theoretically, pneumonic plague can indeed spread from person to person and cause outbreaks. However, its mode of transmission differs significantly from that of SARS-CoV-2. Yersinia pestis is primarily transmitted through large respiratory droplets during close contact, and these particles do not remain suspended in the air for prolonged periods.
Another important difference is that effective antibiotic therapy is available for plague. Without treatment, the disease — particularly pneumonic plague — can become fatal very rapidly, but early diagnosis and prompt initiation of antibiotics significantly improve the prognosis. In addition, close contacts can be identified and monitored, and preventive antibiotic therapy can be provided when indicated.
Therefore, antibiotics alone do not protect against a pandemic — early diagnosis, isolation, infection control, contact tracing, and prompt treatment are crucial. Because of these mechanisms, based on the available data, the Irkutsk case should not be regarded as the beginning of a global pandemic similar to COVID-19.
At the same time, there is certainly reason for caution: pneumonic plague can progress rapidly, and a delayed diagnosis can lead to secondary cases. Therefore, the appropriate response in such cases is a high level of preparedness and rapid epidemiological action — not predicting a pandemic on the basis of unconfirmed information.
