▁stra ining ▁the ▁island ' s ▁ability ▁to ▁co pe ▁with ▁additional ▁cases . ▁ ▁March ▁On ▁ 5 ▁March , ▁the ▁ship ▁made ▁a ▁four - day - long ▁port ▁call ▁at ▁Da ▁N ang , ▁Vietnam . ▁On ▁the ▁last ▁night ▁some ▁sail ors ▁stayed ▁at ▁a ▁hotel ▁where ▁two ▁people ▁had ▁tested ▁positive ▁for ▁COVID - 1 9 , ▁a ▁coron av irus ▁disease ▁identified ▁as ▁the ▁cause ▁of ▁an ▁out break ▁of ▁resp ir atory ▁ill ness . ▁Upon ▁learning ▁this , ▁the ▁crew ▁were ▁ordered ▁back ▁to ▁the ▁ship ▁and ▁the ▁sail ors ▁who ▁had ▁stayed ▁at ▁the ▁hotel ▁were ▁isolated . ▁The ▁ship ▁did ▁not ▁have ▁COVID - 1 9 ▁test ▁k its ▁at ▁the ▁time . ▁The ▁ship ▁depart ed ▁on ▁ 9 ▁March . ▁Over ▁the ▁next ▁weeks ▁the ▁ship ' s ▁medical ▁team ▁monitor ed ▁the ▁crew ▁for ▁any ▁signs ▁of ▁in fection . ▁The ▁sail ors ▁associated ▁with ▁the ▁hotel ▁visit ▁were ▁later ▁tested ▁negative . ▁Sam ples ▁were ▁tested ▁by ▁the ▁Navy ' s ▁mobile ▁labor atory ▁on ▁the ▁ship ▁on ▁ 1 9 ▁March . ▁ ▁On ▁ 2 2 ▁March , ▁the ▁first ▁sail or ▁tested ▁positive . ▁By ▁ 2 4 ▁March , ▁three ▁further ▁sail ors ▁of ▁the ▁flight ▁crew ▁ab o ard ▁had ▁tested ▁positive ▁for ▁the ▁virus , ▁and ▁the ▁four ▁aff lic ted ▁sail ors ▁were ▁flow n ▁to ▁Gu am , ▁as ▁were ▁another ▁five ▁the ▁next ▁day . ▁ ▁Within ▁a ▁few ▁days