Modern diagnosis of Trichomonas vaginalis infection

Recent advances in tests for the sexually transmitted protozoan parasite Trichomonas vaginalis have increased opportunities for diagnosis and treatment of this important sexually transmitted infection. This review summarises currently available tests, highlighting their performance characteristics, advantages and limitations. The recent development of molecular tests for the detection of T vaginalis, including rapid antigen detection and nucleic acid amplification tests, has significantly improved the quality of diagnostics for trichomoniasis, particularly in women. In light of the expanded menu of testing options now available, improved recognition and better control of trichomoniasis are in sight, which should enable the eventual reduction of adverse reproductive consequences associated with T vaginalis infection

Experimental Gonococcal Infection in Male Volunteers: Cumulative Experience with Neisseria gonorrhoeae Strains FA1090 and MS11mkC

Experimental infection of male volunteers with Neisseria gonorrhoeae is safe and reproduces the clinical features of naturally acquired gonococcal urethritis. Human inoculation studies have helped define the natural history of experimental infection with two well-characterized strains of N. gonorrhoeae, FA1090 and MS11mkC. The human model has proved useful for testing the importance of putative gonococcal virulence factors for urethral infection in men. Studies with isogenic mutants have improved our understanding of the requirements for gonococcal LOS structures, pili, opacity proteins, IgA1 protease, and the ability of infecting organisms to obtain iron from human transferrin and lactoferrin during uncomplicated urethritis. The model also presents opportunities to examine innate host immune responses that may be exploited or improved in development and testing of gonococcal vaccines. Here we review results to date with human experimental gonorrhea

Experimental genital tract infection demonstrates Neisseria gonorrhoeae MtrCDE efflux pump is not required for in vivo human infection and identifies gonococcal colonization bottleneck.

The MtrCDE efflux pump of Neisseria gonorrhoeae exports a wide range of antimicrobial compounds that the gonococcus encounters at mucosal surfaces during colonization and infection and is a known gonococcal virulence factor. Here, we evaluate the role of this efflux pump system in strain FA1090 during in vivo human male urethral infection with N. gonorrhoeae using a controlled human infection model. With the strategy of competitive infections initiated with mixtures of wild-type FA1090 and an isogenic mutant FA1090 strain that does not contain a functional MtrCDE pump, we found that the presence of the efflux pump is not required for an infection to be established in the human male urethra. This finding contrasts with previous studies of in vivo infection in the lower genital tract of female mice, which demonstrated that mutant gonococci of a different strain (FA19) lacking a functional MtrCDE pump had a significantly reduced fitness compared to their wild-type parental FA19 strain. To determine if these conflicting results are due to strain or human vs. mouse differences, we conducted a series of systematic competitive infections in female mice with the same FA1090 strains as in humans, and with FA19 strains, including mutants that do not assemble a functional MtrCDE efflux pump. Our results indicate the fitness advantage provided by the MtrCDE efflux pump during infection of mice is strain dependent. Owing to the equal fitness of the two FA1090 strains in men, our experiments also demonstrated the presence of a colonization bottleneck of N. gonorrhoeae in the human male urethra, which may open a new area of inquiry into N. gonorrhoeae infection dynamics and control. TRIAL REGISTRATION. Clinicaltrials.gov NCT03840811

Haemophilus ducreyi Infection Causes Basal Keratinocyte Cytotoxicity and Elicits a Unique Cytokine Induction Pattern in an In Vitro Human Skin Model

Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. Predominantly a cutaneous pathogen, H. ducreyi is present in chancroid ulcers that are characterized by extensive neutrophil accumulation in intraepidermal lesions accompanied by a mononuclear infiltrate in the dermis. We used an in vitro human skin model composed of foreskin fibroblasts and keratinocytes to examine host skin cell interactions with H. ducreyi 35000. Bacteria replicated and persisted in artificial skin for at least 14 days. We observed H. ducreyi inside suprabasal keratinocytes using transmission electron microscopy. Although no bacteria were seen in the basal keratinocyte region, these cells were disrupted in infected cocultures. H. ducreyi infection stimulated increased secretion of interleukin-6 (IL-6) and IL-8 by skin cells. Conversely, tumor necrosis factor alpha and IL-1α levels were not elevated. IL-8 produced in response to H. ducreyi infection may be involved in recruiting polymorphonuclear leukocytes and other inflammatory cells, thereby contributing to the tissue necrosis and ulcer formation characteristic of chancroid

Borderline Personality Disorder Symptom Severity and Sexually Transmitted Infection and HIV Risk in African American Incarcerated Men

Sexually transmitted infections (STI)/HIV rates are disproportionately high among men involved in the criminal justice system. Mental health disorders, including personality disorders, are also elevated among inmates. Borderline personality disorder (BPD) may be an important risk factor for STI/HIV, yet remains relatively understudied, particularly among inmates

Sexual Relationship Power and Semen Exposure Among Female Patients at a Sexually Transmitted Infection Clinic in Kingston, Jamaica

Women’s power in sexual relationships is thought to be an important predictor of condom use. However, research on correlates of condom use often relies on participant reporting of behavior, which has questionable validity. We evaluated the association between scores from the modified Sexual Relationship Power Scale (SRPS-M) and biological detection of semen exposure in a prospective study of adult women attending a sexually transmitted infection clinic in Kingston, Jamaica with cervicitis or abnormal vaginal discharge in 2010–2011. At enrollment, women were counseled to avoid sex while on treatment and were asked to return in 6 days for a follow-up visit. At both study visits, women were administered a questionnaire and had vaginal swabs collected to test for prostate-specific antigen (PSA), a biological marker of recent semen exposure. We found no significant association at enrollment or follow-up between SRPS-M scores and semen exposure, as measured with either self-reported data or PSA positivity. Semen biomarkers could be used to develop and validate new scales on relationship power and self-efficacy related to condom use

Vaginal swab specimen processing methods influence performance of rapid semen detection tests: a cautionary tale

Detection of semen biomarkers in vaginal fluid can be used to assess women’s recent exposure to semen. Quantitative tests for detection of prostate-specific antigen (PSA) perform well, but are expensive and require specialized equipment. We assessed two rapid immunochromatographic strip tests for identification of semen in vaginal swabs

Validation of the Cepheid GeneXpert for Detecting Ebola Virus in Semen

Background: Ebola virus (EBOV) RNA persistence in semen, reported sexual transmission, and sporadic clusters at the end of the 2013-2016 epidemic have prompted recommendations that male survivors refrain from unprotected sex unless their semen is confirmed to be EBOV free. However, there is no fully validated assay for EBOV detection in fluids other than blood. Methods: The Cepheid Xpert Ebola assay for EBOV RNA detection was validated for whole semen and blood using samples obtained from uninfected donors and spiked with inactivated EBOV. The validation procedure incorporated standards from Clinical and Laboratory Standards Institute and Good Clinical Laboratory Practices guidelines for evaluating molecular devices for use in infectious disease testing. Results: The assay produced limits of detection of 1000 copies/mL in semen and 275 copies/mL in blood. Limits of detection for both semen and blood increased with longer intervals between collection and testing, with acceptable results obtained up to 72 hours after specimen collection. Conclusions: The Cepheid Xpert Ebola assay is accurate and precise for detecting EBOV in whole semen. A validated assay for EBOV RNA detection in semen informs the care of male survivors of Ebola, as well as recommendations for public health

Differences in Misreporting of Sexual Behavior Over Time: Implications for HIV Trials

We used data from a prospective study of 300 women attending a sexually transmitted infection clinic in Kingston, Jamaica, to compare participant self-report of recent semen exposure to actual semen exposure measured by prostate-specific antigen in vaginal swabs. Underreporting of semen exposure was significantly more frequent at follow-up than baseline, suggesting the accuracy of reports of sexual behavior may vary over time

Mycoplasma genitalium Infection in Women Attending a Sexually Transmitted Infection Clinic: Diagnostic Specimen Type, Coinfections, and Predictors

In female sexually transmitted infection (STI) clinic attendees, Mycoplasma genitalium (MG) was more frequently detected using vaginal (53/73) versus endocervical (43/73) specimens. In women without other STIs, MG detection (N=44) was associated with age≤ 22 years (odds ratio (OR) 2.53, P=0.006) and clinical evidence of cervicitis (OR 2.11, P=0.03)