You are at no risk of getting HIV infection when you donate blood. This is because the needle and other equipment used for collecting your blood is normally disposable and therefore safe. However, people who get blood transfusion that is infected with HIV have a very high risk of getting HIV infection. The risk of getting HIV infection due to blood transfusion is almost nil in the developed countries such as the US and Europe. This is mainly because of compulsory blood testing for HIV infection before it is transmitted.

Although the National AIDS Control Organisation in India has made testing of blood for HIV before transmission mandatory, some medical experts believe that there is a small risk of transmitting HIV infection through blood transfusion. This is mainly because the blood tests normally done to detect HIV infection in India can identify only the antibodies against HIV. Since the body requires about three to six months to produce antibodies, the HIV test is likely to be negative up to three to six months after getting the infection. Since a person can transmit HIV even before the blood tests indicate the presence of antibodies, there is a low risk of transmitting HIV infection through blood transfusion in India. This risk can increase if there is high level of HIV infection in the general population. Given the several risks involved with blood transfusion (HIV is just one of them), most medical practitioners prefer to give blood transfusion only if there is an emergency and it is essential to preserve life.

In India, blood transfusion is normally given after surgery or accidents when there is excessive loss of blood and severe anaemia due to a wide range of causes. Thalassaemia is one of the important causes of anaemia in India. In this condition, regular blood transfusions are essential for survival. Thalassaemia is a hereditary condition where there is a deficiency in the synthesis of haemoglobin. Since haemoglobin carries oxygen to different parts of the body, defective production of haemoglobin will lead to reduced oxygen carrying capacity of the blood.

Haemophilia is another hereditary disease in which the blood does not clot in case of any injury. Thus, there is risk of excessive bleeding even after minor injuries. People with haemophilia regularly require a substance called Factor VIII, which is prepared from the blood. When the HIV infection was first detected, many people got infected worldwide because of the virus present in Factor VIII. In recent years, the blood used to prepare Factor VIII is given heat treatment so that the HIV gets killed. Factor VIII is therefore not a potential source of HIV infection anymore.