WHO Seeks Cause of Russian Lab Worker’s Death

The WHO says it has not determined what caused a Russian laboratory worker’s fatal severe pneumonia and has found no evidence of ongoing transmission based on information from Russian authorities. Russia reported that tests found no high-threat pathogens among the worker’s contacts, who completed medical observation without developing symptoms, and said no plague case had been registered. The WHO has requested more information about the cause of the illness, the pathogen that prompted public-health measures and reports of another employee with unexplained pneumonia; it says the absence of a confirmed diagnosis leaves key questions unresolved.