All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
AIDS is a fatal and chronic disease which can be regarded as a punishment from Allah, The Almighty, to people in these days because of their dissoluteness, depravity and their actions against the Fitra (natural predisposition upon which Allah created mankind). They are now committing Zina more than ever without shyness or timidity. Some of them are even sexually perverted.
So, they commit pervert acts which any normal human being will find disgusting.
Worse, still, is that some governments, that claim to be civilized, legalize such disgusting acts and accept them.
No doubt that the spread of this dangerous disease in the libertine countries is a punishment from Allah. Allah Says (what means):
• {And whatever strikes you of disaster - it is for what your hands have earned; but He pardons much.} [Quran 42: 30]
• {Corruption has appeared throughout the land and sea by [reason of] what the hands of people have earned so He may let them taste part of [the consequence of] what they have done that perhaps they will return [to righteousness].} [Quran 30: 41]
Imam Malik reported that the Prophet said: “Zina (fornication or adultery) does not become widespread among any nation but that death becomes widespread among them as well.”
Another narration reads: “…but diseases and sickness that were not known among their ancestors become widespread among them.” AIDS is a fatal disease and it was not known before [i.e. in the previous generations].
As for the Hadeeth you mentioned, it is reported by Muslim from Jabir that the Prophet said: “There is a cure for every disease. Whenever an illness is treated with its right remedy, it will, by Allah's permission, be cured.”
An-Nawawi said: “It is as if the Prophet wanted to notify by the last part of his Hadeeth that there cannot be a contradiction with the first part.”
Some might say: “You said there is a cure to every disease and we see many people who get treated but do not get cured.” He said: “That is because of the lack of knowledge not the lack of medicine.”
Imam Ahmad reported that Jaber, may Allah be pleased with him, said: “For each disease, there is a remedy. So, if you obtain the right remedy to the disease, it gets cured by the Will of Allah.”
Allah knows best.