Effect of 10 minutes heat treatment on HIV antibody testing from alternate testing sites

One hundred and thirty-five sera were tested for the presence of antibody to human immunodeficiency virus (HIV) by enzyme immunoassay (EIA) with the Abbott Diagnostics HTLV-III test before and after heating at 56 degrees C for 10 min. Only one serum specimen was repeatedly reactive after heating when compared with the unheated portion (1/135). The specimen was a low level positive (ratio of test over cutoff = 1.6). Fifty-eight different sera, selected to yield a high percentage of positive results, had both their heated and unheated Western blot (WB) results agree completely with repeated EIA testing. An additional 4,244 sera heated at 56 degrees C for 10 min were tested. Of the 330 repeatable EIA positives, only 38 were not confirmed by WB. HIV infectivity in sera was reduced from 10(3.5) TCID50 to 10(1) TCID50 by the same heat treatment. We conclude that heating sera at 56 degrees C for 10 min significantly reduces HIV infectivity and does not significantly affect the results of HIV antibody testing.