Star Trek: Bitter Medicine (Star Trek: Starfleet Corps of Engineers Book 41)

SUMMARY: A routine salvage operation becomes a desperate rescue mission, as the U.S.S. da Vinci encounters a failing abandoned ship-that isn't so abandoned! There is one survivor aboard the derelict vessel: a boy who carries a most deadly disease. Even as the S.C.E. works to salvage the ship, Dr. Lense must race the clock to find a cure for the boy-or condemn him to live out his days alone on the dying vessel!
A routine salvage operation becomes a desperate rescue mission, as the U.S.S. da Vinci encounters a failing abandoned ship -- that isn't so abandoned! There is one survivor aboard the derelict vessel: a boy who carries a most deadly disease.

Even as the S.C.E. works to salvage the ship, Dr. Lense must race the clock to find a cure for the boy -- or condemn him to live out his days alone on the dying vessel!