MULTICENTER EUROPEAN EVALUATION OF HIV TESTING ON SERUM AND SALIVA SAMPLES

Objective: to evaluate the reliability of HIV antibody testing on sali va. Design: matched serum and saliva samples were collected from both seronegative (n = 344) and seropositive (n = 125) individuals in five European countries. Duplicate saliva samples collected with Omni-Sal d evices provided by Saliva Diagnostic System (SDS) were pooled before a nalysis. Methods: all samples were analyzed by Recombinant HIV1 EIA Ca mbridge Bioscience and 2nd generation Abbott HIV 1&2 1A80. EIA procedu res were adapted for saliva testing by modification of sample dilution and/or cut-off calculation. All saliva recording positive and/or doub tful EIA results were further analyzed by Western blot as a confirmato ry method. Results: EIA results obtained from sera analysis from both seropositives and seronegatives allowed for calculation of the tests' sensitivity (HIV1 Biotech: 99.2% - 100%; Abbott: 100%) and specificity (both tests 100%). In the series of 125 saliva samples collected from seropositives, the EIA results were as follows: with Biotech (3 negat ive, 3 in the grey-zone and 119 reactive) and with Abbott (1 negative, 1 in the grey-zone and 123 reactive). One saliva sample found negativ e by both EIA tests, although fulfilling HIV1 WE criteria of positivit y, was collected from an HIV2 infected person. Out of 125 saliva sampl es collected from seropositives, 121 produced positive Western Blot pr ofiles, 4 were indeterminate and 1 was found negative whereas 125/125 sera were found positive. Conclusion: the reliability of HIV testing o f saliva is dependent on the sensitivity of EIA tests and on the crite ria used for the interpretation of Western blot tests as well. Althoug h saliva testing offers numerous advantages for epidemiological purpos es, it should not be recommended for diagnosis.