SEOUL, Aug. 10 (Yonhap) -- The last two members of the virus-hit Cheonghae unit were to be released from a hospital Tuesday, marking the full recovery of all infected service members who had to cut short their anti-piracy missions in waters off Africa and return home following an unprecedented mass infection.All members of the 301-strong Cheonghae unit were airlifted home in July after 247 troops tested positive for COVID-19. Subsequent tests found 25 more cases, raising the total caseload to 272, or 90 percent of the total members.Most of the members who contracted the virus were released from medical facilities last month after making full recoveries, but some had remained in hospitals to receive treatment for mild symptoms.Later on Tuesday, health authorities are scheduled to announce the results of their investigation into the route of the mass infection. Officials earlier said the members are presumed to have contracted the highly transmissible delta variant.Separately, the defense ministry said two soldiers in Paju, north of Seoul, and a sailor in Jinhae in the southeastern city of Changwon have tested positive for the new coronavirus, raising the total caseload reported among the military population to 1,536.Members of the Cheonghae unit get off a KC-330 multirole aerial tanker after it arrives at an air base in Seongnam, south of Seoul, on July 20, 2021. (Yonhap)