Is there a plague outbreak in Russia? If the answer were a clear yes, there shouldn’t be much reason to worry. With swift medical intervention, plague is treatable. But in the nearly three weeks since a worker at a Siberian plague research unit died of a mysterious respiratory illness, state officials have been consistently tight-lipped about what happened and whether there were any further cases. It is this uncertainty that has the World Health Organization (WHO) and international community worried: partly because there is a – very small – risk of…