Thailand says risk from suspected pneumonic plague case in Russia remains low

Thailand’s Department of Disease Control (DDC) has assessed the risk of plague being imported from Russia as low, as it awaits further confirmation from the World Health Organization (WHO) over a suspected pneumonic plague case involving a laboratory worker in Siberia.

The DDC said on Monday (October 5) that its epidemiological assessment had found no evidence of spread beyond the affected area or of community transmission. Thailand’s International Health Regulations National Focal Point (IHR-NFP) has contacted the WHO directly for further information.

Dr Montien Kanasawad, Director-General of the DDC, said foreign reports indicated that a 28-year-old woman working at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East developed severe pneumonia of unknown cause and died after being admitted to hospital on September 29.

At least 197 people who had been in contact with her were reported to be under medical observation. No illness had initially been detected among those contacts, while there was no laboratory confirmation that the woman had died from infection with Yersinia pestis, the bacterium that causes plague, and no evidence of person-to-person transmission, the DDC said.

No additional travel restrictions planned

The DDC said the incident remained geographically limited and the WHO had not issued a warning or recommended tighter travel restrictions.

Dr Direk Khampan, Deputy Director-General of the DDC, said Thailand did not currently need additional restrictions on travel or flights, or special screening measures at international points of entry.

He said Thailand’s existing surveillance system was sufficient to respond to the situation. Travellers displaying suspicious symptoms — including fever and severe pneumonia combined with a relevant exposure history — can be isolated, treated with antibiotics and investigated promptly.

Plague is classified as a dangerous communicable disease under Thailand’s Communicable Diseases Act 2015. Suspected cases must therefore be reported immediately without waiting for laboratory confirmation or a final diagnosis.

Russian case remains unconfirmed

International reports have identified the deceased laboratory worker as Darya Shipilova. Russian authorities have said she died from “pneumonia of unknown aetiology”, while unconfirmed media reports have raised the possibility of pneumonic plague and an accidental laboratory exposure.

Russia’s public health watchdog, Rospotrebnadzor, said further testing found no microorganisms associated with the woman’s professional work and reported no accident involving pathogenic microorganisms at the institute. Contacts have nevertheless been placed under medical observation and precautionary restrictions have been introduced in the area.

Reuters reported that the WHO and Russian authorities assessed the wider public-health risk as low, with no plague infections confirmed among known contacts.

What is pneumonic plague?

Plague is an infectious disease caused by the bacterium Yersinia pestis. Pneumonic plague is a severe form in which the infection affects the lungs and can spread between people through infectious respiratory particles, generally requiring close contact with an infected person.

The WHO says plague can be severe and potentially fatal if untreated, but antibiotics are effective, making early diagnosis and treatment important.

The DDC said it would continue monitoring developments and provide further information if new evidence emerges. Members of the public seeking information can contact the DDC hotline on 1422.

Sources: Reuters, Department of Disease Control