Licensed tests for antibody to human T-lymphotropic virus type III. Sensitivity and specificity

Before the discovery of the etiologic agent of the acquired immunodeficiency syndrome (AIDS), substantial epidemiologic evidence suggested that the responsible agent could be transmitted by blood and blood products such as factor VIII. The Public Health Service and the Food and Drug Administration therefore took general steps to increase the safety of the blood supply. With the discovery of the human T-lymphotropic virus type III (HTLV-III) it became possible to test blood for evidence of infection using an antibody detection assay. Currently licensed tests to detect antibody to HTLV-III range in sensitivity between 93% and 99%, and all are above 99% in specificity. The Public Health Service has issued provisional recommendations regarding the voluntary use of the antibody tests to screen blood and plasma donations.