The disease that once ravaged Europe still exists: could plague return to Spain?
Plague, one of the deadliest diseases in history, has once again made headlines in recent days following the death of a scientist in Irkutsk, in Siberia. The woman died from pneumonia of unknown origin, which...
Plague, one of the deadliest diseases in history, has once again made headlines in recent days following the death of a scientist in Irkutsk, in Siberia. The woman died from pneumonia of unknown origin, which raised suspicions of a possible pneumonic plague infection.
However, the Russian authorities have stated that no cases of plague have been confirmed in the region and that tests carried out on the deceased woman’s contacts have come back negative. The World Health Organization (WHO) has requested additional information to clarify what happened and has offered its support to the Russian authorities.
Although no cases of routine transmission of this disease have been recorded in Europe for decades, the bacterium that causes it remains present in different parts of the world and continues to cause human infections every year.
Does plague currently exist in Spain and Europe?
Plague is not currently circulating routinely in Spain or in the rest of Europe. According to the European Centre for Disease Prevention and Control (ECDC), the disease has been absent from the continent for more than 50 years.
This does not mean, however, that the bacterium has been eradicated from the planet. Plague is caused by Yersinia pestis, a microorganism that lives naturally in certain populations of small mammals, especially rodents, and in the fleas that infest them.
The bacterium can be transmitted to humans through the bites of infected fleas, contact with tissues or body fluids from infected animals and, in the case of pneumonic plague, via respiratory particles from sick people.
Therefore, although the current risk for the Spanish and European population is very low, the disease can still appear wherever there are animal reservoirs of the bacterium.
Is there a risk of plague in Spain? What the Health Ministry says
Spain has gone decades without registering locally acquired cases of plague, but it maintains active epidemiological surveillance of the disease. In April 2026 the Public Health Commission updated the national protocol, revising case definitions, the epidemiological characteristics of the infection and the information that must be collected in the event of possible infections.
This update, which predates the incident in Siberia, adds to the early-warning mechanisms already in place in Spain. For its part, the European Union examined the Russian case on 7 October, although international health authorities are still awaiting information that could clarify the cause of the researcher’s death.
Where does plague still occur in the world?
According to the WHO, plague remains endemic in several countries in Africa, Asia and the Americas. Between 2019 and 2025, most of the human cases reported to the organisation were concentrated in Madagascar and the Democratic Republic of the Congo. In Madagascar, for example, cases of bubonic plague are recorded virtually every year during the epidemic season, which usually runs from September to April.
The disease also appears sporadically in regions of Asia and the Americas. In the United States, an average of around seven human cases are reported each year, mainly in rural areas in the west of the country.
The persistence of the bacterium in wild animals explains why it is so difficult to eliminate the disease completely, even when human cases are rare.
What is the difference between bubonic and pneumonic plague?
Plague can present in three main forms: bubonic, pneumonic and septicaemic. Bubonic plague is the most common and usually occurs after the bite of an infected flea. It causes fever, general malaise and painful swelling of the lymph nodes, known as buboes.
Pneumonic plague affects the lungs and is particularly dangerous because it can be transmitted from person to person via respiratory particles. Without treatment, it can progress rapidly and prove fatal. Septicaemic plague, meanwhile, occurs when the bacterium multiplies in the bloodstream and can lead to a severe, generalised infection.
Unlike what happened during the great epidemics of the past, plague can now be treated with antibiotics. However, early diagnosis is essential to avoid serious complications and reduce the risk of death.
What risk does the Siberia case pose for Europe?
The suspected case of pneumonic plague in Siberia has prompted European health authorities to monitor the situation closely. The European Commission included the Russian incident on the agenda of its Health Security Committee meeting on 7 October, while the ECDC pointed out that there was no evidence of secondary cases or sustained person-to-person transmission.
The WHO has also concluded that the risk to the European region is very low. Although the disease has not been eradicated worldwide, its presence on other continents does not mean that Europe is facing a new epidemic.
Epidemiological surveillance, early detection of cases and treatment with antibiotics are crucial tools to prevent its spread. Plague still exists, but today’s health situation is very different from the one that allowed the Black Death to devastate Europe in the 14th century.
