Etiology of genital ulcer disease in Dakar, Senegal, and comparison of PCRand serologic assays for detection of Haemophilus ducreyi

We used PCR assays to determine the etiology of genital ulcers in patients presenting to a sexually transmitted disease clinic in Dakar, Senegal, and evaluated the ability of mo PCR tests (groEL and recD) and two serological tests (adsorption enzyme immunoassay [EIA] and lipooligosaccharide [LOS] EW ) to detect current Haemophilus ducreyi infection, We found that in this po pulation, H. ducreyi, T. pallidum, and herpes simplex virus HSV DNA were de tected in 56, 15, and 13% of 39 genital ulcer specimens, respectively, and H. ducreyi DNA was detected in 60% (3 of 5) of samples from ulcerated bubos . Among 40 consecutive patients with genital nicer disease and with suffici ent sample for both PCR assays, the recD and groEL H. ducreyi PCR assays we re 83% concordant, with the recD PCR assay detecting six (15%) additional p ositive specimens and the groEL assay detecting one (3%) additional positiv e specimen. Compared to PCR, the adsorption EW and LOS EM tests had sensiti vities of 71 and 59% and specificities of 57 and 90% respectively, for the diagnosis of current RI. ducreyi infection, While these differences in spec ificity could be due either to previous infection with H. ducreyi or to the detection of cross-reacting antibodies, only 6% of patients from a nearby family planning clinic gave a positive reaction in both the adsorption EIA and LOS EIA assays, indicating that cross-reacting antibodies are not preva lent among clinic attendees in this city, Our studies indicate that the ads orption EIA detects both current and past infection, while the LOS EIA assa y is more specific for current infection with H. ducreyi in this population .