Why is HIV infection difficult to cure, even with treatment with multiple medications?

HIV and AIDS :-

HIV infection is difficult to cure even by multiple treatment with multiple medications because this is a kind of highly communicable virus and it decreases the resistance of our body everytime . Up to date there is no systematic and effective treatment for this . Slightly it affects the whole system of our body and does not get easily treated with any special medications .

answer; i believe the answer is moderate level;