Screening for the Presence of a Disease by Pooling Sera Samples

Abstract Screening of pooled urine samples was suggested during the Second World War as a method for reducing the cost of detecting syphilis in U.S. soldiers. Recently, pooling has been used in screening for human immunodeficiency virus (HIV) antibody to help curb the further spread of the virus. Pooling reduces the cost but also—and probably more importantly—offers a feasible way to lower the error rates associated with labeling samples when screening low-risk HIV populations. For example, given the limited precision of the presently available test kits, when the screened population has a prevalence of 4 per 1,000 (which is roughly the estimated U.S. prevalence), the probability that a sample labeled positive is antibody-free can be reduced from approximately 90% (if each sample is tested individually) to about 2%. Furthermore, screening pooled sera samples can also be used to reduce the probability that a sample labeled negative in fact has antibodies up to 40-fold in such a population—an important cons...