PRAINHA, Brazil (Feb. 26, 2019) Lt. John Sullivan conducts thyroid ultrasound training with Brazilian navy Cmdr. Carlos Marsico aboard Brazilian navy hospital ship NAsH Carlos Chagas (U 19) off the coast of Prainha, Brazil during a medical clinic, Feb. 26. The visit marks the eighth and penultimate stop of a month-long mission by four U.S. Navy physicians and their Brazilian navy counterparts embarked aboard Chagas to exchange medical expertise and to bring medical care to isolated communities along the Amazon River. (U.S. Navy photo by Mass Communication Specialist 1st Class Byron C. Linder/Released)