“The U.S. State Department says it expelled two Cuban diplomats earlier this year after several Americans at the U.S. Embassy in Havana experienced strange medical symptoms and were either recalled to the U.S. or allowed to come home. State Department spokeswoman Heather Nauert said the ‘incidents’ were first discovered in late 2016, but she declined to provide any details.”
Scott Neuman, “Cuban Diplomats Expelled After U.S. Embassy Staff ‘Incidents’ In Havana,” NPR.org, Aug. 9, 2017