Transmission of HIV infection by seronegative blood in Thailand.

In Thailand the human immunodeficiency virus (HIV) seropositivity rate in donated blood increased 150 times from 1987 to 1993 from 0.0065% to 0.95%. Although the National Blood Center and large hospitals initiated HIV antibody screening of all blood in 1987 HIV seronegative blood can pose a serious hazard to recipients because of the risk of viremia during the window period of early HIV infection. Transfusion-associated acquired immunodeficiency syndrome (AIDS) from seronegative blood was first reported in Thailand in 1990 in three thalassemic children. To reduce this risk HIV P24 Ag screening has been mandatory since 1990 and is estimated to prevent about 180 cases of transfusion-associated HIV transmission from seronegative blood per year. Less effective yet recommended is donor self-exclusion. Other preventive measures recommended include exclusion of donors from high-risk groups public education sensitive and early detection of IgM antibodies promotion of autologous blood transfusion and the use of blood substitutes or blood stimulating factors.