Plague is caused by the bacterium Yersinia pestis; pneumonic plague can spread between people through respiratory droplets US President Donald Trump expressed concern over a suspected plague case in Russia after a researcher died and 200 people were quarantined. Key points and original sources are listed below.

• Plague is caused by the bacterium Yersinia pestis; pneumonic plague can spread between people through respiratory dropletsS1

• US President Donald Trump expressed concern over a suspected plague case in Russia after a researcher died and 200 people were quarantined. Separately, Trump raised suspicion Iran for the attack incident aboard the flydubai flight last week.S2