IMMUNODEFICIENCY Virus), the virus that causes AIDS(Acquired Immune Deficiency Syndrome), is transmitted only by particular body fluids: blood, semen, pre-seminal fluid (pre-cum), vaginal and rectal fluid, and breast milk.There is no fluid entering the body from one person to another during the embrace.AIDS is a continuum of disorders CAUSED by the human immunodeficiency virus ( HIV) infection. AIDS was first recognized by the United States Centers for Disease Control and Prevention (CDC) in 1981 and its cause - HIV infection - was identified at the beginning of the decade.The most POPULAR mode of transmission of HIV is through sexual contact with an infected person.The second most frequent mode of transmission of HIV is by blood and blood products. HIV is a retrovirus that mainly infects human immune system components such as CD4+ T cells, macrophages, and dendritic cells.It destroys CD4+ T cells DIRECTLY and indirectly.