Refining Timely Diagnosis of Early Syphilis by Using Treponema pallidum PCR or IgM Immunoblotting Next to Conventional Serology for Syphilis.

Treponema pallidum subsp. pallidum is a fastidious spirochete and the etiologic agent of syphilis, a sexually transmitted infection (STI). Syphilis diagnoses and disease staging are based on clinical findings and serologic testing. Moreover, according to most international guidelines, PCR analysis of swab samples from genital ulcers is included in the screening algorithm where possible. It has been suggested that PCR might be omitted from the screening algorithm due to low added value. As an alternative to PCR, IgM serology might be used. In this study, we wanted to establish the added value of PCR and IgM serology for diagnosing primary syphilis. Added value was defined as finding more cases of syphilis, preventing overtreatment, or limiting the extent of partner notification to more recent partners. We found that both PCR and IgM immunoblotting could aid the timely diagnosis of early syphilis in ~24% to 27% of patients. PCR has the greatest sensitivity and can be applied to cases with an ulcer with suspected reinfection or primary infection. In the absence of lesions, the IgM immunoblot could be used. However, the IgM immunoblot has better performance in cases with suspected primary infection than in reinfections. The target population, testing algorithm, time pressures, and costs should determine whether either test provides sufficient value to be implemented in clinical practice.

Low positivity rate after systematic screening for Trichomonas vaginalis in three patient cohorts from general practitioners, STI clinic and a national population-based chlamydia screening study.

OBJECTIVE: The goal of this multi-cohort study is to investigate the positivity rate of Trichomonas vaginalis (TV) among three distinct Dutch patient populations and its relation with Chlamydia trachomatis (CT) positivity. Few studies have been performed in Europe where TV positivity rate seems to be low. Additionally, the majority of earlier studies have focused on high risk or specific populations. METHODS: A random selection of men and women from a national population-based chlamydia screening, attendees of a sexually transmitted infections (STI) clinic and a non-selected population from general practitioners (GPs) were systematically screened for TV and CT using PCR. The associations among TV and CT co-infection, age and gender were studied. RESULTS: A total of 2079 individuals were studied. A TV positivity rate of 1.5% was observed in the medium risk GP cohort followed by 0.7% in the low risk population-based cohort and 0.6% in the high risk STI clinic. TV was found in 0.7% of CT positives and a similar 1.1% among CT negatives. All TV positive individuals in this study were women. CONCLUSIONS: The positivity rate of TV was low (<2%) and comparable in all three populations studied. We found no association between TV and CT infection.