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Irkutsk Anti-Plague Research Institute of Siberia and Far East. Institute workers in a lab.
Opinionscientist plague death
Russian plague death What is plague and how dangerous is it?
A Russian researcher has died after working at a plague research centre. But while the disease has a terrifying history, modern medicine has changed the picture dramatically.
PRESIDENT DONALD TRUMP is looking “very strongly” at the case of a Russian lab technician who died at a plague research centre in Irkutsk, Siberia.
The death has been announced as “pneumonia of undetermined aetiology”. Irkutsk’s governor said, “No microorganisms linked to the woman’s work had been found in her biological samples.”
A state TV station in Irkutsk reported on 5 October that she died the previous week in a hospital in Shelekhov, a town outside Irkutsk.
Unconfirmed reports suggested the woman fell ill either after breaking a test tube containing the pathogen or following a field trip to a region where plague is found in wild rodents.
Russian authorities are reported to have quarantined a hospital and are monitoring contacts of an employee at a plague research institute.
The World Health Organization (WHO) said on Monday of this week that it was in contact with Russian health authorities to verify what happened, what testing is underway, and any further international public health implications.
“Based on official information available, the public health risk to the general population appears to be low,” a WHO spokesperson said, adding that its risk assessment would be updated once more information was available.
What is plague and how dangerous is it?
Plague is an infectious disease caused by the bacterium Yersinia pestis that is usually found in small mammals and fleas. It is transmitted to animals from fleas. Humans can be infected either by being bitten by an infected flea, contact with infectious bodily fluids or contaminated materials, or by inhaling respiratory particles from a patient with pneumonic plague.
Pneumonic plague is the most infectious form and can trigger severe epidemics through person-to-person transmission by inhaling respiratory particles.
Historically, plague was responsible for widespread pandemics with high mortality. It was known as the “Black Death” during the 14th century, responsible for more than 50 million deaths in Europe. Nowadays, plague is easily treated with antibiotics and the type of standard precautions we became so familiar with during the Covid-19 pandemic to prevent person-to-person transmission.
Types of plague: bubonic, pneumonic and septicaemic
There are three main clinical forms of infection: bubonic, pneumonic and septicaemic.
Bubonic plague is the most common form and is caused by the bite of an infected flea. The bacteria, Y. pestis, enter the body and travel through the lymphatic system to the nearest lymph node where they replicate themselves. The lymph node becomes inflamed, tense and painful, and is called a “bubo.”
Left untreated, the inflamed lymph nodes can turn into open, pus-filled sores. Human-to-human transmission of bubonic plague is rare. Bubonic plague can advance and spread to the lungs, causing pneumonic plague, or to the bloodstream, causing septicaemic plague.
Pneumonic plague is the most infectious form. Incubation is very short – as little as 24 hours. Any person with pneumonic plague can transmit it via respiratory particles to other humans. Untreated, it is invariably fatal though early treatment (within 24 hours) can lead to high recovery rates.
Septicaemic plague occurs when Y. pestis gets into the bloodstream. It can lead to a complicated severe illness, including multi-organ failure, respiratory distress and bleeding under the skin. It is fatal if untreated.
Signs and symptoms
Bubonic plague typically causes fever, chills, body aches, vomiting and painful and inflamed lymph nodes. In the recent movie, Hamnet, William Shakespeare’s son, died from bubonic plague in 1596 at the age of 11.
Symptoms of pneumonic plague include early onset of shortness or breath, coughing, often with blood stained sputum.
Symptoms of septicaemic plague include bleeding under the skin, cyanosis (blue discolouration of the skin) and tissue death or necrosis of the extremities. Multi-organ failure and severe breathing difficulties can follow.
Where is plague found?
Plague cases have occurred in Africa, Asia and South America, but since the 1990s, most human cases have been reported in Africa, particularly in the Democratic Republic of the Congo and Madagascar.
Outbreak in India, 1994
One of the largest outbreaks in recent decades occurred in India in 1994. In Betrayal of Trust (2001), health and science writer Laurie Garrett described arriving in Surat, India by train in the torrid September heat, and being the only passenger to get off the train while throngs of masked Suratis elbowed their way onboard.
In less than a week, 500,000 Suratis had fled the city. An estimated 600,000 day workers and business travellers who normally visited the city stayed away, resulting in fewer than half of Surat’s typical daily census of 2.2 million remaining. They were the poorest of the city’s lower caste citizens who could not conjure up the train fare of 70 rupees ($2.50).
Within four weeks, fires burned in every city in India, as mountains of refuse were doused with petrol and set alight. Flea-ridden rats were blamed for an epidemic that had as much to do with bad housing, non-existent healthcare and human panic.
In fact, the epidemic started hundreds of miles to the south-east in a rural part of Maharashtra State, the capital of which is Bombay.
An earthquake a year earlier in September 1993 obliterated 10,000 villages, one million homes and killed more than 10,000 people.
Aftershocks continued for days, causing a human exodus of survivors. Before they left, many hastily harvested their crops and locked the food inside whatever structures that remained.
The following year in August 1994, people returning to their villages, opened their sealed stores to be overwhelmed by clouds of black fleas and a carpet of black rats, allowing the bacteria-ridden fleas to rapidly transmit infection to humans.
The last US death from pneumonic plague occurred in Arizona in July 2025, according to the CDC. The young man worked with sick cats, believed to be the source of infection.
In Ireland, the most devastating outbreak of plague arrived via trade ships at Drogheda, Dalkey and Howth in 1348-1349, wiping out an estimated 14,000 people in Dublin.
In 1900, cases occurred in Ireland following outbreaks in ports like Glasgow. Strict local quarantines prevented a more widespread epidemic.
The final official case in Ireland was over a century ago, in 1920. The urgency to de-rat ships formed the origins of the discipline of public health.
Diagnosis and treatment
Confirmation of plague is made by identifying Y pestis from a sample of pus from a bubo, blood or sputum. A more rapid dipstick test can detect Y. pestis antigen and is used widely in Africa and South America.
Antibiotics and supportive therapy are effective if patients are diagnosed in time – usually within the first 24 hours.
Vaccination is only recommended for high-risk groups, such as laboratory personnel who are constantly exposed to the risk of contamination, and healthcare workers.
Plague outbreak
Initial steps in managing an outbreak of plague include identifying the most likely source of infection, including both flea and rodent control. Healthcare workers should be advised on standard personal protective equipment and receive antibiotic chemoprophylaxis for up to seven days. Patients need to be isolated, and close contacts should be identified and offered antibiotic chemoprophylaxis. Cases should be immediately reported to public health authorities.
People with pneumonic plague get sick very quickly, usually within 24 hours, which has the potential to slow spread. Because patients feel so unwell, they are less likely to be walking around in their communities and even less likely to be travelling. This does reduce the risk of person-to-person spread and the likelihood of widespread transmission between countries. In comparison, Covid-19 did not present with severe symptoms in the early stage of infection, therefore making the risk of person-to-person transmission much higher.
In the days of Louis Pasteur, the father of the germ theory of disease in the late nineteenth century, public health was local and manageable enough if backed with sufficient political support.
Now, the “community” has expanded to the entire world. It watched and squirmed as TB overwhelmed prisons in the US, Europe and Asia during the late 1980s and 1990s; and HIV vanquished an entire generation of Africans over two decades from the mid-1980s to the early 2000s.
More recently, the Covid-19 pandemic emerged from China in 2019; an Mpox epidemic spread in 2022; and measles continues to spiral, due to low vaccination rates in the US.
Laurie Garret described how, as the world grows ever smaller, community grow anxious.
“Though it empathises, it fears that what is ‘over there’ could ‘come here.’
“Public health needs to be – must be – global prevention. Now that would be real progress.”
Dr Catherine Conlon is a public health doctor in Cork.
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