A person may be infected in four primary ways: (1) by using a contaminated needle or syringe, (2) through sexual intercourse (vaginal, anal, or oral) with an infected person, (3) by blood transfusions and blood products, although this threat has been reduced in more developed countries where blood is now screened for HIV antibodies, and (4) by his or her HIV - infected mother, who can infect the baby either before or during birth or while breast - feeding.
मगर इसकी रोकथाम की बात करने से पहले आइए हम देखें कि एड्‌स वायरस (HIV) कैसे फैलता है और कैसे नहीं फैलता ।