FIG. 1.

Calculation of the posttest probability of being HHV-8 infected or uninfected by using the pretest probability of infection, results from testing in an immunofluorescence assay, and a 2 by 2 table. Panel A depicts a generic population and outlines the steps involved in the calculation. A high-risk group of homosexual men without KS is depicted in panel B, and a low-risk group of children, virginal women, and heterosexual men is depicted in panel C. A population of 1,000 individuals is chosen in panels B and C for ease in calculations. Justification for the pretest probabilities and assay sensitivity and specificity values is found in the methods. LANA IFA refers to an immunofluorescence assay, using isolated nuclei from BCBL-1 cells as target antigen, for antibodies directed against latency-associated nuclear antigen. REPA/LANA IFA refers to an immunofluorescence assay for antibodies directed against both replication-associated and latency-associated antigens.