Q1) In 1982, CDC report explained that 3 persons who had before received whole blood transfusions developed acquired immuno deficiency syndrome (AIDS). In 1948, after discorvery of human Immuno deficiency virus (HIV), 5 companies were licensed to produce enzyme- linked immunos orbent assay(EIA, then called ELISA) test. Kits for detecting HIV antibody. In march, 1985, first kit was approved by FDA. Numerous complex issues were explained even before licensure such as false positive test results to find out whether test- positive blood donors must  be notified. It is now march2, 1985. First HIV antibody test kits will arrive in blood banks in state in few hours, meeting with state Epidemiologist to explain suitable use of this test are commissioner of health , medical director of regional blood bank, and chief of state drug abuse commissioner.

To help discussion, state epidemiologist turns to pre licensure information regarding sensitivity and specificity of test kit A. Information points out that sensitivity of test kit a is 95% and specificity is 98%.

i) Do you think that the EIA is a good screening test for blood bank? What would you suggest the blood bank director about notification of EIA- positive blood donors?

ii) Do you think that EIA performs will enough to justify informing test- positive clients in the drug abuse clinics that they are positive for HIV?

iii) If sensitivity and specificity remain constant, determine the relationship of prevalence to predictive value positive and predictive value negative?