The World Health Organization is seeking more information from Russia after a 28-year-old laboratory worker at the Irkutsk Anti-Plague Research Institute died of severe pneumonia on October 2.
Russian authorities rejected reports linking the death to pneumonic plague or a lab accident, stating the sanitary situation is stable and the cause of illness is undetermined.
US President Donald Trump stated the United States is watching the situation strongly and will speak with Russian President Vladimir Putin about the case.