Effect of Sexually Transmitted Disease (STD) Coinfections on Performance of Three Commercially Available Immunosorbent Assays Used for Detection of Herpes Simplex Virus Type 2-Specific Antibody in Men Attending Baltimore, Maryland, STD Clinics

Abstract

ABSTRACT Two hundred seventy-nine serum samples from men attending sexually transmitted disease (STD) clinics in Baltimore, Maryland, were tested for herpes simplex virus type 2 (HSV-2)-specific antibody by three immunosorbent glycoprotein G-2-based assays (the Kalon, Focus, and Biokit assays). The results for all samples with positive results were confirmed by Western blotting (91/279; 32.6% HSV-2 seroprevalence). All patients were also tested for Chlamydia trachomatis , Neisseria gonorrhoeae , Trichomonas vaginalis , Mycoplasma genitalium , human immunodeficiency virus type 1, and hepatitis C virus. The Kalon assay performed very well with samples from this population (90.8% sensitive, 99.4% specific), whereas the Focus assay had a sensitivity (82.6%) much lower than that shown previously. For 19.7% of the samples, the Biokit assay gave an indeterminate result. It was found that the odds of a sample having a Biokit assay indeterminate result compared to that of having a definitive positive or negative results were 3.88 times greater for subjects concurrently infected with N. gonorrhoeae , after the effects of other STDs were controlled for ( P = 0.001; 95% confidence interval, 1.78, 8.45). Unfortunately, we were unable to control for HSV-1 infection status in the regression model, which, on the basis of χ 2 analysis, might also affect the clarity of the Biokit test. The recommended index cutoff value of 1.1 for the Focus and Kalon assays was found to be optimal for this population.