EVALUATION OF A QUANTITATIVE COMPETITIVE PCR ASSAY FOR MEASURING HERPES-SIMPLEX VIRUS-DNA CONTENT IN GENITAL-TRACT SECRETIONS

Previous studies have shown an association between the approximate tit er of herpes simplex virus (HSV) DNA in clinical specimens and the abi lity to isolate HSV from genital secretions. To control for variance i n amplification conditions, we developed a competitive quantitative PC R (QC PCR) for the detection of HSV DNA. The assay accurately measured from 10 to 10(6) copies of HSV DNA. We compared the QC PCR with our p revious semiquantitative detection method and found concordance for 61 of 63 positive specimens. We also evaluated the HSV DNA content from individual swabs of genital secretions obtained from individual sites of the genital tract (cervix, vulva, and rectum) with that from one sw ab with secretions from all three sites. The concordance for detecting HSV DNA was 91%; for only 4 of 143 collection days was there a > 1 lo g difference between the two collection methods. A single swab with se cretions from all three genital sites and evaluated in a QC PCR format can accurately measure the frequency of subclinical and clinical shed ding of HSV and the titer of HSV shed from the genital region. Such an approach should be very useful in the evaluation of antiviral chemoth erapy for HSV.