Following are a number of back-translations as well as a sample translation for translators of Deuteronomy 28:21:

• Kupsabiny: “He shall send you bad illnesses until all shall be destroyed completely in that land that you are going to take.” (Source: Kupsabiny Back Translation)
• Newari: “Then the LORD will send diseases bit by bit into the land which you are about to enter to possess, until you will no longer exist.” (Source: Newari Back Translation)
• Hiligaynon: “The LORD will-send you (plur.) diseases until you (plur.) will-be-destroyed there in the land that you (plur.) are-to-enter and possess.” (Source: Hiligaynon Back Translation)
• English: “Yahweh will cause you to experience terrible diseases,
  until not one of you remains alive in the land that you are about to enter and occupy.” (Source: Translation for Translators)