Since the medics were first imprisoned in 1999, 52 of the children infected in the Benghazi hospital have died of Aids.
The first time the doctor and nurses were given the death penalty in 2004, the Supreme Court reversed the ruling after protesters said the trail was conducted unfairly.
The defendants say the charges against them are an attempt to cover up unhygienic hospital conditions, and retracted confessions they say were forced out of them with torture. Their lawyers have announced they will be taking advantage of a final appeal allowed under Libyan law in order to fight the new verdict.
The defense lawyers claim that the HIV virus was present in the hospital prior to the nurses' employment there in 1998. Medical experts testified in defense of the defendants, with an Oxford University research team concluding "the subtype of HIV involved began infecting patients long before March 1998, the date the prosecution claims the crime began." One of the scientists who discovered HIV also spoke on the medics' behalf, and the World Medical Association and the International Council of Nurses said the verdict ignored scientific evidence.
Bulgarian Foreign Minister Ivailo Kalfin said the ruling was deeply disappointing. Libya has suggested that the death sentences would be commuted if Bulgaria paid 10 million euros (about $13 million) to each of the victims' families, but Bulgaria refused on the grounds that such a payment would be akin to admitting guilt.
The parents of the children who were infected by the disease have expressed happiness with the verdict, with one father saying the doctor and nurses sold their consciences to the devil. However, a relative of one of the defendants remained optimistic that the convicted medical staff would be released, but said it would take time.