WHO unsure what caused pneumonia that killed plague-lab worker in Russia

The World Health Organization (WHO) remains unsure about the cause of pneumonia that led to the death of a Russian lab worker at an anti-plague research center in Siberia, according to a statement released on Saturday. The lab worker, who died on October 2, did not exhibit symptoms of plague, and no other cases of severe pneumonia linked to her have been identified.

The WHO noted that tests conducted on the worker and those who came in contact with her were negative for high-threat pathogens. Despite these findings, the absence of a confirmed diagnosis for the deceased lab worker remains a key uncertainty. Russian authorities had reported that the lab worker was appropriately vaccinated and that no microorganisms linked to her work were found in her body.

Upon the worker's illness, about 200 people were quarantined, sparking public health concerns on social media. Since the COVID-19 pandemic, global health officials have been particularly vigilant about fatal pneumonia cases of undetermined cause. Russian authorities stated that they had completed health checks on all the worker's contacts and provided full information to the WHO.