190204-N-ZW825-0304 AMAZON RIVER, Brazil (Feb. 4, 2019) The Brazilian navy Oswaldo Cruz-class hospital ship NAsH Carlos Chagas (U19) enters the Amazon River to commence a month-long humanitarian mission, Feb. 4, 2019. Four U.S. Navy doctors will work with the Brazilian navy aboard Carlos Chagas to exchange medical expertise with their counterparts 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)