Trichomoniasis and other sexually transmitted infections: results from the 2001-2004 National Health and Nutrition Examination Surveys

Imidazole Carbamates as a Promising Alternative for Treating Trichomoniasis: In Vitro Effects on the Growth and Gene Expression of Trichomonas vaginalis

Metronidazole (MTZ) is the most common drug used against Trichomonas vaginalis (T. vaginalis) infections; however, treatment failures and high rates of recurrence of trichomoniasis have been reported, suggesting the presence of resistance in T. vaginalis to MTZ. Therefore, research into new therapeutic options against T. vaginalis infections has become increasingly urgent. This study investigated the trichomonacidal activity of a series of five imidazole carbamate compounds (AGR-1, AGR-2, AGR-3, AGR-4, and AGR-5) through in vitro susceptibility assays to determine the IC50 value of each compound. All five compounds demonstrated potent trichomonacidal activity, with IC50 values in the nanomolar range and AGR-2 being the most potent (IC50 400 nM). To gain insight into molecular events related to AGR-induced cell death in T. vaginalis, we analyzed the expression profiles of some metabolic genes in the trophozoites exposed to AGR compounds and MTZ. It was found that both AGR and MTZ compounds reduced the expression of the glycolytic genes (CK, PFK, TPI, and ENOL) and genes involved in metabolism (G6PD, TKT, TALDO, NADHOX, ACT, and TUB), suggesting that disturbing these key metabolic genes alters the survival of the T. vaginalis parasite and that they probably share a similar mechanism of action. Additionally, the compounds showed low cytotoxicity in the Caco-2 and HT29 cell lines, and the results of the ADMET analysis indicated that these compounds have pharmacokinetic properties similar to those of MTZ. The findings offer significant insights that can serve as a basis for future in vivo studies of the compounds as a potential new treatment against T. vaginalis.

Association Between Serum 25-Hydroxyvitamin D and Trichomonas vaginalis Infection Among American Adults: NHANES 2013-2016

BACKGROUND

Previous studies have suggested that vitamin D may possess anti-infection properties, but the relationship between vitamin D and Trichomonas vaginalis infection remains unexplored.

METHODS

Using data from the National Health and Nutrition Examination Survey between 2013 and 2016, we conducted multivariate regression analyses and subgroup analyses to investigate the association between 25-hydroxyvitamin D (25[OH]D) levels and T. vaginalis infection, ensuring the robustness of our results.

RESULTS

The final sample included data from 4318 individuals aged 20 to 59 years, among which 92 were diagnosed with T. vaginalis infection. For every 10 nmol/L increase in serum 25(OH)D level, there was a 22% reduction in the likelihood of T. vaginalis infection incidence (adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.69-0.90). Similarly, higher concentration tertiles demonstrated relatively lower infection ratios compared with the tertile with the lowest 25(OH)D concentration (aOR, 0.54 [95% CI, 0.30-0.95; P = 0.030] for T2; aOR, 0.23 [95% CI, 0.09-0.61; P < 0.001] for T3).

CONCLUSIONS

Our cross-sectional study indicates a negative association between 25(OH)D levels and the prevalence of T. vaginalis infection. However, further high-quality evidence is needed to establish a causal relationship between 25(OH)D levels and T. vaginalis infection, as well as to evaluate the potential role of vitamin D supplementation in preventing T. vaginalis infection.

The Past, Present, and Future in the Diagnosis of a Neglected Sexually Transmitted Infection: Trichomoniasis

More than one million curable sexually transmitted infections occur every day. Trichomonas vaginalis is one of the main infections responsible for these epidemiological data; however, the diagnosis of this protozoan is still mainly based on microscopic and culture identification. The commercialization of immunological tests and the development of molecular techniques have improved the sensitivity of classical methods. Nevertheless, the fact that trichomoniasis is a neglected parasitic infection hinders the development of novel techniques and their implementation in routine diagnosis. This review article shows the different methods developed to identify T. vaginalis in population and the difficulties in diagnosing male and asymptomatic patients. The importance of including this parasite in routine gynecological screening, especially in pregnant women, and the importance of considering T. vaginalis as an indicator of high-risk sexual behavior are also discussed.

Detection of Trichomonas vaginalis by Allplex™ STI Essential Assay (Seegene) in clinical samples from the Brazilian public health system users

The failures in Trichomonas vaginalis (TV) infection diagnosis leave more than half of cases unidentified. In this report, urine and vaginal discharge samples were analyzed by wet mount, culture examination, and real-time PCR by Allplex™ (Seegene®) kit, in a population assisted by the Brazilian Public Health System. From 747 samples, 2.81% were positive for TV in wet mount and culture, and 3.88% by Allplex™. Samples kept at - 80 ºC for 22 months did not impair the PCR technique. The sensitivity for wet mount, culture, and Allplex™ was 72, 100, and 100%, respectively. Allplex™ technique showed highest detection of TV.

Persistent Trichomonas vaginalis infections and the pseudocyst form

Recent studies have proposed that Trichomonas vaginalis, the causative agent of trichomoniasis [the most common nonviral sexually transmitted infection (STI) in humans] can establish persistent infections in the vagina. T. vaginalis infections are often asymptomatic but can have adverse consequences such as increased risk of HIV-1 infection and cervical cancer. Despite this, it remains an understudied infection. A potential agent of persistent infections is the 'pseudocyst', a spherical form of T. vaginalis identified by several laboratories and linked to persistence in related species such as the avian parasite Trichomonas gallinae and cattle parasite Tritrichomonas foetus. Additional robust and reproducible research on pseudocysts and persistent T. vaginalis infections is required, which may ultimately shed light on how to better diagnose and treat trichomoniasis.

Evaluating the utility of the Allplex STI Essential Assay to determine the occurrence of urogenital sexually transmitted infections among symptomatic and asymptomatic patients in Cape Town, South Africa

BACKGROUND

Sexually transmitted infections are among the most commonly occurring infections globally, with countries in sub-Saharan Africa exhibiting disproportionately higher prevalence rates. Numerous reports indicate the need for accurate detection, epidemiological characterisation, and appropriate management of these infections. This prospective observational laboratory study sought to determine the occurrence of STI, using a validated molecular assay as a diagnostic and surveillance tool in our setting.

METHODS

Urogenital swabs from symptomatic and asymptomatic patients, submitted to the National Health Laboratory Service, at Groote Schuur Hospital, from 04 August 2021-03 February 2022, for routine microbiological investigations, were subjected to the Allplex™ STI Essential Assay (Seegene Inc, South Korea) to determine the distribution of STI pathogens in our setting. This multiplex assay includes C. trachomatis, Mycoplasma genitalium, Mycoplasma hominis, N. gonorrhoeae, Trichomonas vaginalis, Ureaplasma parvum, and Ureaplasma urealyticum. Correlations between detected organisms and participant age and clinical indications for testing were determined using Stata® software.

RESULTS

A total of 148 urogenital swabs (91.2% from women) were included in the analysis, of which 56/148 (37.84%) were from symptomatic patients. Up to 83.8% of the samples tested positive for ≥1 organism, with all seven target organisms detected in at least one sample. Ureaplasma parvum was the most common organism detected, followed by N. gonorrhoeae, M. hominis, U. urealyticum, T. vaginalis, C. trachomatis, with M. genitalium being the least detected. All 25 samples submitted for routine antenatal Group B Streptococcal screening were positive for at least one STI organism, and one sample from sexual non-accidental injury tested positive for five different organisms.

CONCLUSIONS

STIs comprise a variety of organisms in our setting, with many patients exhibiting coinfection with multiple organisms. This suggests the need for a critical evaluation of current syndromic testing and treatment guidelines so as to stem inadvertent spread of STI organisms and the development of resistance. The use of molecular testing methods may improve detection, especially in resource limited settings, providing speedy results, and thus allowing for guided therapy in only infected patients.

Successful Treatment of Persistent 5-Nitroimidazole-Resistant Trichomoniasis With an Extended Course of Oral Secnidazole Plus Intravaginal Boric Acid

ABSTRACT

We describe a case of persistent 5-nitroimidazole-resistant trichomoniasis cured after 14 days of oral secnidazole and intravaginal boric acid. Secnidazole may be an important treatment option for resistant trichomoniasis, particularly in women who fail other regimens, including higher doses of oral metronidazole and tinidazole for longer durations of time.

Secnidazole: a treatment for trichomoniasis in adolescents and adults

INTRODUCTION

Single-dose 2-g oral secnidazole (SEC), newly approved by the U.S. Food and Drug administration (FDA) for treatment of trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various micro-organisms. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other FDA-approved treatments for trichomoniasis in the United States - metronidazole and tinidazole - SEC has favorable pharmacokinetics, including a longer half-life and a lower minimal lethal concentration.

AREAS COVERED

This work summarizes the chemistry and pharmacology of SEC and reviews the evidence on its efficacy, tolerability, and safety for the treatment of trichomoniasis.

EXPERT OPINION

SEC is an efficacious, well tolerated, and safe treatment for patients aged ≥12 years with trichomoniasis. Single-dose administration makes it a favorable treatment option, especially in cases where adherence to multi-dose treatment regimens may be low.

In vitro and in silico trichomonacidal activity of 2,8-bis(trifluoromethyl) quinoline analogs against Trichomonas vaginalis

Trichomoniasis is a great public health burden worldwide and the increase in treatment failures has led to a need for finding alternative molecules to treat this disease. In this study, we present in vitro and in silico analyses of two 2,8-bis(trifluoromethyl) quinolines (QDA-1 and QDA-2) against Trichomonas vaginalis. For in vitro trichomonacidal activity, up to seven different concentrations of these drugs were tested. Molecular docking, biochemical, and cytotoxicity analyses were performed to evaluate the selectivity profile. QDA-1 displayed a significant effect, completely reducing trophozoites viability at 160 µM, with an IC₅₀ of 113.8 µM, while QDA-2 at the highest concentration reduced viability by 76.9%. QDA-1 completely inhibited T. vaginalis growth and increased reactive oxygen species production and lipid peroxidation after 24 h of treatment, but nitric oxide accumulation was not observed. In addition, molecular docking studies showed that QDA-1 has a favorable binding mode in the active site of the T. vaginalis enzymes purine nucleoside phosphorylase, lactate dehydrogenase, triosephosphate isomerase, and thioredoxin reductase. Moreover, QDA-1 presented a level of cytotoxicity by reducing 36.7% of Vero cells' viability at 200 µM with a CC₅₀ of 247.4 µM and a modest selectivity index. In summary, the results revealed that QDA-1 had a significant anti-T. vaginalis activity. Although QDA-1 had detectable cytotoxicity, the concentration needed to eliminate T. vaginalis trophozoites is lower than the CC₅₀ encouraging further studies of this compound as a trichomonacidal agent.

Trichomonas infection in pregnant women: a nationwide cohort study

Trichomoniasis is the most prevalent sexually transmitted infection worldwide, and is associated with adverse pregnancy outcomes. However, Trichomonas vaginalis (TV) has received little public health attention, and only limited data are available on prevalence of TV and other Trichomonas-associated syndromes in pregnant women. This study aimed to determine associations between pregnancy and incident trichomoniasis-related diseases. Data of pregnant women were extracted from the National Health Insurance Research Database (NHIRD) of Taiwan. The pregnant cohort included 113,781 women, and cases were randomly matched by age, and index year with those of non-pregnant women (n = 113,781). Risk of incident trichomoniasis-related diseases was also not significantly different between pregnant and non-pregnant women. However, after stratifying by age or level of care, the younger subgroup among pregnant women had a higher risk of incident trichomoniasis-related diseases than did the younger subgroup in non-pregnant women, while the elder subgroup among pregnant women had a lower risk of incident trichomoniasis-related diseases than did the same subgroup in non-pregnant women (all p < 0.05). The higher level of care (medical center) subgroup among pregnant women had a lower risk of incident trichomoniasis-related diseases than did the same subgroup in non-pregnant women. In conclusions, although pregnancy is not significantly associated with risk of trichomoniasis-related diseases, data of the present study support an enhanced high level of medical care for pregnant women, emphasizing the potential of high medical care in reduced incidence of trichomoniasis-related diseases. This may be an effective strategy for reducing various pregnancy complications associated with trichomoniasis-related diseases.

Secnidazole for Trichomoniasis in Women and Men

INTRODUCTION

Secnidazole (SEC), newly FDA-approved for trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various infections. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other approved treatments for trichomoniasis in the U.S.-metronidazole and tinidazole-SEC has favorable pharmacokinetics, including a longer half-life, and a lower minimal lethal concentration against Trichomonas vaginalis.

OBJECTIVES

Provide an updated, comprehensive review of the literature evaluating SEC as a treatment for trichomoniasis in women and men.

METHODS

We conducted a search to identify existing research on SEC and trichomoniasis. On August 6, 2021, we searched MEDLINE using the terms "secnidazole" and "trichomon.*" We excluded reviews, editorials, case reports, and small case series.

RESULTS

We identified 29 articles; 14 of which were included: 5 reported in vitro pharmacologic data on SEC, 6 were observational studies, and 4 were controlled clinical trials (1 observational study also reported in vitro pharmacologic data). Six studies reported data on women only, 1 on men only, and 3 on women and men. These studies showed that SEC-as a single dose or 3-day course-had comparable efficacy to multi-dose metronidazole for treating trichomoniasis in women and men, was generally well tolerated by patients, and had a favorable pharmacokinetic profile. A single 2-g dose of SEC also led to a microbiologic cure rate of 92.2% in the first randomized, double-blind, placebo-controlled study of trichomonas-infected US-based women.

CONCLUSION

SEC is an efficacious and safe treatment for women and men with trichomoniasis. Single-dose administration makes it a favorable treatment option for patients, especially in cases where adherence to other multi-dose treatment regimens could be problematic. Christina A. Muzny and Olivia T. Van Gerwen. Secnidazole for Trichomoniasis in Women and Men. Sex Med Rev 2022;10:255-262.

Impact of aetiological screening of sexually transmitted infections during pregnancy on pregnancy outcomes in South Africa

BACKGROUND

Sexually transmitted infections (STIs) during pregnancy may increase the risk of adverse pregnancy outcomes. STI syndromic management is standard of care in South Africa but has its limitations. We evaluated the impact of diagnosing and treating curable STIs during pregnancy on adverse pregnancy and birth outcomes.

METHODS

We combined data from two prospective studies of pregnant women attending public sector antenatal care (ANC) clinics in Tshwane District and Cape Town, South Africa. Pregnant women were enrolled, tested and treated for STIs. We evaluated the association between any STI at the first ANC visit and a composite adverse pregnancy outcome (miscarriage, stillbirth, preterm birth, early neonatal death, or low birthweight) using modified Poisson regression models, stratifying by HIV infection and adjusting for maternal characteristics.

RESULTS

Among 619 women, 61% (n = 380) were from Tshwane District and 39% (n = 239) from Cape Town; 79% (n = 486) were women living with HIV. The prevalence of any STI was 37% (n = 228); C. trachomatis, 26% (n = 158), T. vaginalis, 18% (n = 120) and N. gonorrhoeae, 6% (n = 40). There were 93% (n = 574) singleton live births, 5% (n = 29) miscarriages and 2% (n = 16) stillbirths. Among the live births, there were 1% (n = 3) neonatal deaths, 7% (n = 35) low birthweight in full-term babies and 10% (n = 62) preterm delivery. There were 24% (n = 146) for the composite adverse pregnancy outcome. Overall, any STI diagnosis and treatment at first ANC visit was not associated with adverse outcomes in women living with HIV (adjusted relative risk (aRR); 1.43, 95% CI: 0.95-2.16) or women without HIV (aRR; 2.11, 95% CI: 0.89-5.01). However, C. trachomatis (aRR; 1.57, 95% CI: 1.04-2.39) and N. gonorrhoeae (aRR; 1.69, 95% CI: 1.09-3.08), were each independently associated with the composite adverse outcome in women living with HIV.

CONCLUSION

Treated STIs at the first ANC visit were not associated with adverse pregnancy outcome overall. In women living with HIV, C. trachomatis or N. gonorrhoeae at first ANC were each independently associated with adverse pregnancy outcome. Our results highlights complex interactions between the timing of STI detection and treatment, HIV infection and pregnancy outcomes, which warrants further investigation.

Kinetic and Molecular Docking Studies to Determine the Effect of Inhibitors on the Activity and Structure of Fused G6PD::6PGL Protein from Trichomonas vaginalis

Trichomoniasis is a sexually transmitted disease with a high incidence worldwide, affecting 270 million people. Despite the existence of a catalog of available drugs to combat this infection, their extensive use promotes the appearance of resistant Trichomonas vaginalis (T. vaginalis), and some side effects in treated people, which are reasons why it is necessary to find new alternatives to combat this infection. In this study, we investigated the impact of an in-house library comprising 55 compounds on the activity of the fused T. vaginalis G6PD::6PGL (TvG6PD::6PGL) protein, a protein mediating the first reaction step of the pentose phosphate pathway (PPP), a crucial pathway involved in the parasite's energy production. We found four compounds: JMM-3, CNZ-3, CNZ-17, and MCC-7, which inhibited the TvG6PD::6PGL protein by more than 50%. Furthermore, we determined the IC50, the inactivation constants, and the type of inhibition. Our results showed that these inhibitors induced catalytic function loss of the TvG6PD::6PGL enzyme by altering its secondary and tertiary structures. Finally, molecular docking was performed for the best inhibitors, JMM-3 and MCC-7. All our findings demonstrate the potential role of these selected hit compounds as TvG6PD::6PGL enzyme selective inhibitors.

Comparison of diagnostic methods and analysis of socio-demographic factors associated with Trichomonas vaginalis infection in Sri Lanka

BACKGROUND

Trichomonas vaginalis infection is underreported due to nonspecific clinical presentation and the nonavailability of sensitive laboratory diagnostic tests at the clinical setup. Hence, this study was designed to compare the sensitivity and specificity of microscopy and culture methods with polymerase chain reaction (PCR). The socio-demographic factors associated with the infection were explored.

METHODS

The study was carried out at the National Sexually Transmitted Diseases and Acquired Immuno Deficiency Syndrome Control Programme in Colombo and Sexually Transmitted Diseases and Acquired Immuno Deficiency Syndrome Control Programme in Kandy. Samples were collected from a total of 385 patients including, 272 females (70.7%) and 113 males (29.3%), and tested using microscopy (wet mount and Giemsa staining), culture, and PCR. Genus-specific primer set (TFR1/TFR2) that amplifies 5.8S rRNA and species-specific primer sets (TV16Sf-2/TV16Sr-2 and TVK3/7) that amplifies 18S rRNA and repetitive DNA, respectively, were used. Patient's socio-demographic and sexual behaviour data were obtained using a standard interviewer-administered questionnaire. Data were analyzed with R statistical software Version 3.6.3.

RESULTS

The overall prevalence of trichomoniasis was 4.4% (17/385). Of these, six (1.6%) were positive for microscopic examination, 7 (1.8%) were positive for culture, and 13 (3.4%) for TVK3/7, 15 (3.9%) for TV16Sf/r, and TFR1/2 17 (4.4%) were positive for PCR. Sensitivities of PCR using TFR1/2, TV16Sf/r, and TVK3/7 primer sets were 100%, 88.20%, and 76.50%, respectively, against the expanded gold standard. Trichomoniasis was associated with age above 36 (p = 0.033), not using condoms in last three months (p = 0.016), multiple sex partners (p = 0.001), reason for attendance (p = 0.027), symptomatic nature (p = 0.015), and the presence of other sexually transmitted diseases (p = 0.001).

CONCLUSIONS

The study highlighted that age over 36 years, multiple sex partners, not using condoms, reason for attendance, symptomatic nature, and having other sexually transmitted diseases can increase the risk of acquiring trichomoniasis. Furthermore, this study confirmed PCR as highly sensitive and specific diagnostic test for the diagnosis of trichomoniasis in comparison to microscopy and culture methods.

Brazilian Protocol for Sexually Transmitted Infections, 2020: infections causing vaginal discharge

The topic of vaginal discharge is one of the chapters of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Health Care for People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health in 2020. The chapter has been developed based on scientific evidence and validated in discussions with specialists. This article presents epidemiological and clinical aspects associated with vaginal discharge conditions, as well as guidance to health service managers and health professionals. Screening, diagnosing, and treating these conditions, the main complaints among women seeking health services, caused by infectious or non-infectious factors, also are presented. Besides, information is presented on surveillance, prevention, and control actions to promote knowledge of the problem and provide quality care and effective treatment.

In healthcare servicing cases of sexually transmitted infections, vaginal discharge is the main referred symptom, common among pregnant women.

Adolescent Trichomonas vaginalis in a High-burdened Region of the Southern United States

BACKGROUND

We evaluated the clinical management and risk factors for Trichomonas vaginalis-positive adolescents in upstate South Carolina.

METHODS

An Epic electronic medical record report was generated to identify any physician-ordered T. vaginalis test from February 2016 to December 2017 for patients aged 12 to 18 years within the Prisma Health Upstate system. Utilizing a case-control study design of patients with a documented T. vaginalis diagnostic result, we reviewed records of patients with physician-ordered T. vaginalis tests for demographics, clinical disease course, sexually transmitted infection test results, treatment order and dosage, infection risk factors, comorbidities, pregnancy term, and neonatal birth outcomes.

RESULTS

Of 789 male and female adolescents with physician-ordered T. vaginalis tests, 44% had a documented result. Of those with a document test result, 13% were T. vaginalis positive. Cases (n = 45) and randomly selected negative controls (n = 45) were all girls. Cases were more likely to be African American, symptomatic, and present with vaginal discharge, pain, and vulvar itch. T. vaginalis patients were more likely to have documented histories of chlamydia (P < 0.0001) and gonorrhea (P = 0.0191), with 18% having concurrent triple infections (T. vaginalis, chlamydia, and gonorrhea). All 26 pregnant girls with T. vaginalis delivered full-term, healthy infants.

CONCLUSIONS

We identified a disproportionally high burden of T. vaginalis infection, with an alarmingly high rate of triple infections, among a population of suspected high-risk adolescents. Our results indicate the need to clarify infection prevalence, develop pediatrician-focused education campaigns, and elucidate potentially modifiable risk factors for these high-risk patients.

Incidence and Prevalence of Trichomonas vaginalis Infection Among Persons Aged 15 to 59 Years: United States, 2018

BACKGROUND

Trichomonas vaginalis (TV) is a sexually transmitted parasite associated with multiple adverse outcomes in women. Estimating TV incidence is challenging because of its largely asymptomatic presentation.

METHODS

Per-capita prevalence was estimated using the National Health and Nutrition Examination Survey, 2013 to 2018. Incidence was estimated using ordinary differential equations assuming static incidence at steady state and fit using Bayesian techniques. Model inputs included estimates of proportion of asymptomatic cases, natural clearance, and time to symptomatic treatment seeking. Posterior distributions were drawn, and uncertainty was reported, from 25th (Q1) to 75th (Q3) percentiles. Aggregated measures were estimated by combining component distributions.

RESULTS

Among 15- to 59-year-olds in 2018, the number of prevalent TV infections was 2.6 (Q1, 2.4; Q3, 2.7) million overall, 470,000 (Q1, 414,000; Q3, 530,000) among men, and 2.1 (Q1, 2.0; Q3, 2.2) million among women; the numbers of incident infections were 6.9 (Q1, 6.2; Q3, 7.6) million, 3.3 (Q1, 2.8; Q3, 3.8) million, and 3.5 (Q1, 3.1; Q3, 4.0) million among all persons, men, and women, respectively. Persons aged 15 to 24 years comprised 15.6% and 16.3% of all prevalent and incident infections, respectively; prevalence and incidence in both sexes increased with age. Incidences in both sexes were highly dependent on estimates of natural clearance, which were based on few data.

CONCLUSIONS

Prevalence and incidence of TV are substantial in the United States, particularly among those 25 years or older. Although estimated prevalence is higher in women, estimated incidence is similar in men and women. Data on key parameters of TV infection are limited; future research should focus on clarifying the natural history of TV.

Atomic Structure of the Trichomonas vaginalis Double-Stranded RNA Virus 2

Trichomonas vaginalis viruses (TVVs) are double-stranded RNA (dsRNA) viruses that cohabitate in Trichomonas vaginalis, the causative pathogen of trichomoniasis, the most common nonviral sexually transmitted disease worldwide. Featuring an unsegmented dsRNA genome encoding a single capsid shell protein (CSP), TVVs contrast with multisegmented dsRNA viruses, such as the diarrhea-causing rotavirus, whose larger genome is split into 10 dsRNA segments encoding 5 unique capsid proteins.

Trichomonas vaginalis, the causative pathogen for the most common nonviral sexually transmitted infection worldwide, is itself frequently infected with one or more of the four types of small double-stranded RNA (dsRNA) Trichomonas vaginalis viruses (TVV1 to 4, genus Trichomonasvirus, family Totiviridae). Each TVV encloses a nonsegmented genome within a single-layered capsid and replicates entirely intracellularly, like many dsRNA viruses, and unlike those in the Reoviridae family. Here, we have determined the structure of TVV2 by cryo-electron microscopy (cryoEM) at 3.6 Å resolution and derived an atomic model of its capsid. TVV2 has an icosahedral, T = 2*, capsid comprised of 60 copies of the icosahedral asymmetric unit (a dimer of the two capsid shell protein [CSP] conformers, CSP-A and CSP-B), typical of icosahedral dsRNA virus capsids. However, unlike the robust CSP-interlocking interactions such as the use of auxiliary “clamping” proteins among Reoviridae, only lateral CSP interactions are observed in TVV2, consistent with an assembly strategy optimized for TVVs’ intracellular-only replication cycles within their protozoan host. The atomic model reveals both a mostly negatively charged capsid interior, which is conducive to movement of the loosely packed genome, and channels at the 5-fold vertices, which we suggest as routes of mRNA release during transcription. Structural comparison of TVV2 to the Saccharomyces cerevisiae L-A virus reveals a conserved helix-rich fold within the CSP and putative guanylyltransferase domain along the capsid exterior, suggesting conserved mRNA maintenance strategies among Totiviridae. This first atomic structure of a TVV provides a framework to guide future biochemical investigations into the interplay between Trichomonas vaginalis and its viruses.

[Brazilian Protocol for Sexually Transmitted Infections 2020: infections causing vaginal discharge]

The topic of vaginal discharge is one of the chapters of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health in 2020. The chapter has been developed based on scientific evidence and validated in discussions with specialists. This article presents epidemiological and clinical aspects related to vaginal discharge conditions, as well as guidelines for health service managers and health professionals about screening, diagnosing and treating these conditions, which are one of the main complaints among women seeking health services, and which may be caused by infectious or non-infectious factors. In addition, information is presented on strategies for surveillance, prevention and control actions, in order to promote knowledge of the problem and provision of quality care and effective treatment.

Impact of point-of-care testing and treatment of sexually transmitted infections and bacterial vaginosis on genital tract inflammatory cytokines in a cohort of young South African women

OBJECTIVES

STIs cause inflammation that is detrimental for both HIV risk and reproductive health. We assessed the impact of point-of-care (POC) STI testing, immediate treatment and expedited partner therapy (EPT) on genital tract cytokines among a cohort of young South African women.

METHODS

HIV-negative women underwent POC testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) by Xpert CT/NG and OSOM TV, and for bacterial vaginosis (BV) by microscopy. Women with STIs and/or BV received immediate treatment, EPT for STIs and retested after 6 and 12 weeks. Concentrations of 48 cytokines were measured in cervicovaginal fluid at each visit using multiplex ELISA technology. The impact of STI treatment on cytokine concentrations was assessed by multivariable linear mixed models and principal component analysis.

RESULTS

The study enrolled 251 women with median age of 23 years (IQR 21-27). The prevalence of CT, NG and TV were 14.3%, 4.4% and 4.0%, and 34.3% had BV. Women with STIs or BV at baseline (n=94) had significantly higher concentrations of pro-inflammatory cytokines (interleukin (IL)-1α, IL-1β, IL-6, tumour necrosis factor (TNF)-α, TNF-β, IL-18 and macrophage inflammatory factor (MIF)) and chemokines (IL-8, IL-16, macrophage inflammatory protein (MIP)-1α, IFN-α2, monokine induced by gamma interferon (MIG), monocyte chemoattractant protein (MCP)-3, regulated on activation normal T cell expressed and secreted and eotaxin) compared with women without (n=157). STI treatment was strongly associated with reduced concentrations of pro-inflammatory cytokines IL-6 (p=0.004), IL-1β (p=0.013), TNF-α (p=0.018) and chemokines MIG (p=0.008) and growth-related oncogene (GRO)-α (p=0.025). A lower Nugent score was associated with a reduction in pro-inflammatory cytokines IL-1α (p=0.003), TNF-related apoptosis-inducing ligand (p=0.004), MIF (p=0.010) and IL-18 (p<0.001), but an increase in chemokines MIG (p=0.020), GRO-α (p<0.001), IP-10 (p<0.001), MIP-1β (p=0.008) and MCP-1 (p=0.005). Principal component analysis showed differences in STI and BV-related inflammatory profiles, but that resolution restored a profile consistent with vaginal health.

CONCLUSIONS

A comprehensive STI intervention effectively reduced genital inflammation among young women, thereby improving vaginal health and potentially reducing HIV risk.

Offering routine trichomonas vaginalis testing to patients presenting for abortion at an urban hospital-based clinic

INTRODUCTION

The Centers for Disease Control and Prevention recommend considering screening asymptomatic women for trichomonas in high-prevalence settings. Whether urban abortion clinics constitute such a setting is unknown.

MATERIAL AND METHODS

We offered trichomonas screening to patients presenting for abortion from October 2018 to February 2019 as a practice improvement and conducted a chart review.

RESULTS

Ninety-two percent (593/644) of patients underwent testing. Trichomonas prevalence was 10.0% (95% CI 7.7-12.6). Ninety five percent of patients diagnosed were treated. Testing only symptomatic patients would have missed 98% of infections.

CONCLUSIONS

Trichomonas was highly prevalent, and universal testing and treatment was feasible in an urban abortion clinic.

Association between human papillomavirus vaccine status and sexually transmitted infection outcomes among females aged 18-35 with a history of sexual activity in the United States: A population survey-based cross-sectional analysis

BACKGROUND

Current human papillomavirus (HPV) vaccine coverage in the United States (in 2019, 66-70%), remains below the Healthy People 2020 coverage goal of 80%. HPV vaccine misinformation, including parental concerns of sexual risk-compensation influence vaccine uptake. We examined the association between HPV vaccination and sexually transmitted infection (STI) outcomes.

METHODS

Of the 20,146 participants from 2013 to 2014 and 2015-2016 cycles of the National Health and Nutrition Examination Survey, 1050 females aged 18-35 with a history of sexual activity had complete case data. Roa-Scott Chi-squared and F-tests assessed survey-weighted socio-demographic differences between vaccinated and unvaccinated participants. Weighted logistic regression assessed crude and adjusted associations between self-reported HPV vaccination (none vs. ≥ 1dose) and lab-confirmed STIs (trichomonas and chlamydia) and vaccine-type HPV (6/11/16/18). As a sensitivity analysis, we conducted weighted-propensity score (PS) models and inverse probability weighting by vaccination status. PS and logistic regression were estimated through survey-weighted logistic regression on variables including race, education, income, marital status, US citizenship, cycle year and age.

RESULTS

Overall, 325 (31.8%) females with a history of sexual activity were HPV vaccinated, of which 22 (6.1%) received the vaccine at the routine-recommended ages of 11-12, 65.7% were vaccinated after their self-reported sexual debut, 3.8% had a lab-confirmed STI and 3.5% had vaccine-type HPV. There was no association between HPV vaccination and any STIs (adjusted odds ratio [aOR] 0.67, 95%CI:0.38-1.20), and vaccinated participants had 61% reduced odds of vaccine-type HPV (vs. unvaccinated; aOR 0.39, 95%CI:0.19-0.83). Results from the PS sensitivity analysis were similar to the main findings.

CONCLUSION

Among females who reported a history of sexual activity, HPV vaccination status was protective against vaccine-type HPV and not associated with lab-based STI outcomes. Although findings may be susceptible to reporting bias, results indicating low vaccine uptake at routine-recommended ages requires additional efforts promoting HPV vaccination before sexual-debut.

Mycoplasma genitalium and Trichomonas vaginalis: addressing disparities and promoting public health control of two emerging sexually transmitted infections

PURPOSE OF REVIEW

Mycoplasma genitalium (M. genitalium) and Trichomonas vaginalis (T. vaginalis), sexually transmitted infections that remain non-reportable in the United States, may lead to pelvic inflammatory disease (PID) and adverse pregnancy outcomes if left untreated. Prevalence estimates have highlighted socioeconomic and racial/ethnic disparities in rates of infection. This review summarizes the recent literature on M. genitalium and T. vaginalis with a focus on the epidemiology, screening, and treatment of M. genitalium and T. vaginalis.

RECENT FINDINGS

The burden of T. vaginalis testing remains on women. Antimicrobial resistance is of great concern for M. genitalium. Comprehensive screening and treatment guidelines present an opportunity to address these public health concerns.

SUMMARY

M. genitalium and T. vaginalis infections disproportionately affect sexual and racial/ethnic minorities and those facing socioeconomic disparities. The availability of nucleic acid amplification test testing has facilitated accurate diagnosis of both disorders. Safe and efficacious treatments are available for treatment of both disorders. Integrating macrolide resistance testing into treatment algorithms for M. genitalium and dual antibiotic therapy may prove a useful strategy for future US-based guidance. Public health reporting and increased public awareness campaigns are key next steps to addressing the observed reproductive health disparities.

Prevalence and risk factors for Trichomonas vaginalis infection among adults in the U.S., 2013-2014

OBJECTIVE

Trichomonas vaginalis (TV) infection is common, curable, and associated with significant reproductive morbidity and risk for HIV infection. This analysis updates estimates of the prevalence of asymptomatic TV infection, and its associated risk factors, in the non-institutionalized U.S. population.

METHODS

We analyzed data from 4057 individuals who participated in the National Health and Nutrition Examination Survey (NHANES) 2013-2014 data collection cycle. Participant interviews ascertained demographic characteristics, self-reported tobacco use, and sexual history. Self-collected urine specimens from participants aged 18 to 59 years were tested for TV infection using the Gen-Probe Aptima TV assay. Cotinine was assayed from serum to provide a biomarker of recent tobacco exposure. Weighted percentages are provided to account for unequal selection probabilities among participants and adjustments for non-response.

RESULTS

Our sample included 1942 men (49.2%, 95% Confidence Interval [CI] 48.0-50.5) and 2115 women (50.8%, 95%CI 49.5-52.0). The infection prevalence among men was 0.5% (n = 16; 95%CI 0.2-1.0) and 1.8% (n = 55; 95%CI 1.1-3.1) in women. After controlling for participant characteristics associated with TV infection, females had a 5.2-fold increased odds of being infected compared to men (adjusted odds ratio (aOR) 5.2, 95% CI 2.4-11.4). Non-Hispanic blacks were more likely to be infected compared to non-Hispanic whites (aOR 11.2, 95% CI 4.6-27.2). Individuals below the federal poverty level were more likely to be infected compared to those earning >3 times the federal poverty level (aOR 6.7, 95% CI 1.7-26.6), and active smokers were more likely to be infected compared to participants with no nicotine exposure (aOR 8.7, 95% CI 4.1-18.2).

CONCLUSION

Trichomonas vaginalis infection continues to be relatively common, especially in women, smokers, non-Hispanic blacks, and in groups of lower socioeconomic status. Identifying the demographic characteristics of populations in the United States disproportionately affected by TV could impact screening and treatment of this infection in clinical practice. Further research on whether screening and treating for asymptomatic TV infection in high-risk populations improves risk for reproductive morbidity and HIV infection is warranted.

Trichomoniasis in a tertiary hospital of Madrid, Spain (2013-2017): prevalence and pregnancy rate, coinfections, metronidazole resistance, and endosymbiosis

Trichomoniasis is the most prevalent curable sexually transmitted infection (STI) worldwide and a risk factor for the acquisition of other STIs and adverse pregnancy outcomes. The objectives of this study were to determine the prevalence of T. vaginalis and related coinfections in women attending a third-level hospital of Madrid (Spain). A retrospective study of 24,173 vaginal exudates from women with suspected vaginitis was conducted between 2013 and 2017. Likewise, among T. vaginalis positive samples, co-occurrence with gonorrhea, chlamydia, syphilis, VIH, Mycoplasma hominis, and Ureaplasma urealyticum was checked. Moreover, seven T. vaginalis isolates from 2017 were randomly collected for endobionts, drug resistance, and microsatellite (MS) instability determinations. The prevalence of T. vaginalis was 0.8% between 2013 and 2017. Less than 20% of patients with trichomoniasis were submitted to a complete screening for other genital pathogens. From that, two patients were coinfected with chlamydia and three with syphilis. Surprisingly, 6.4% of positive samples were diagnosed among pregnant women, showing an alarming increase from 3.2% (2014) to 10% (2017). Among the isolates randomly analyzed, five carried T. vaginalis virus, five harbored mycoplasmas, and one was metronidazole-resistant. The molecular genotyping showed a high variability in the three MS evaluated. To our knowledge, this is the first study in Spain that evaluates the prevalence of trichomoniasis in general and pregnant population and includes biomolecular determinations. These results warn about the increasing prevalence and highlight the importance of including T. vaginalis detection in routine gynecological revisions with special emphasis on childbearing age women and patients with previous STIs.

Prevalence of Trichomonas vaginalis Infection Among US Males, 2013-2016

Background

Trichomoniasis results from adhesion of Trichomonas vaginalis to the mucous membrane of the urethra or vagina. It has been estimated to have a higher incidence rate than both gonorrhea and chlamydia combined. Although females can experience both clinical symptoms and obstetrical complications, male infections are largely asymptomatic and often unreported. We aim to estimate the prevalence of trichomoniasis in US males using the National Health and Nutrition Examination Survey (NHANES) database.

Methods

The NHANES database was queried for all men aged 18-59 years during the years 2013-2016. During these years, the survey included urine testing for trichomoniasis using transcription-mediated amplification. Information was also obtained regarding patient demographics and other sexually transmitted infections.

Results

Overall, 0.49% of men aged 18-59 years tested positive for trichomoniasis. The highest rate was seen in black men (3.6%). There was no significant association with trichomoniasis and age. Higher rates of infection were seen in smokers, those with herpes simplex virus type 2 (HSV-2) infection, men who had sex at an early age, those with less condom usage, and those with more lifetime sexual partners.

Conclusion

The rates of trichomonas infection in US males are lower than in women. Infections are strongly associated with black males, HSV-2 infection, and other factors known to increase rates of sexually transmitted infection. This information may be helpful for counseling, screening, and management of patients.

Retrospective Chart Analysis of Child and Adolescent Trichomonas vaginalis Infection in Houston, Texas

BACKGROUND

Trichomonas vaginalis infection causes significant morbidity in the United States. Despite its high national disease burden, the epidemiologic characteristics of child and adolescent cases are not well understood. In this study, we aimed to describe the socioeconomic, transmission risk factors, clinical manifestations, and geospatial variables associated with cases of T vaginalis infection in the Houston, Texas, metropolitan area.

METHODS

We performed a retrospective chart abstraction of all T vaginalis cases at 2 large pediatric hospitals in Houston between 2008 and 2016.

RESULTS

We identified 87 patients (mean age, 16 years; range, 4-18 years); 30% of them were asymptomatic, and 39% were coinfected with another sexually transmitted infection(s). Almost all T vaginalis infections in sexually assaulted patients were diagnosed incidentally. Geospatial analysis identified clustering of cases in areas of high poverty and in minority populations.

CONCLUSIONS

Our findings indicate that children and adolescents are at risk for T vaginalis infection; however, their risk factors might differ from those in adults. In addition, our geospatial analysis revealed the need for dedicated resources in neighborhoods associated with health disparities to prevent future incident cases.

Survey of Obstetrician-gynecologists in the United States About Trichomoniasis, 2016

We assessed knowledge, attitudes, and practices concerning trichomoniasis of American College of Obstetricians and Gynecologists members, finding discrepancies between practice and recommendations in screening/treatment of human immunodeficiency virus-positive patients and retesting/retreatment.

Purpose

Trichomoniasis is the most prevalent nonviral sexually transmitted infection (STI) in the United States. It can present with vaginitis in women and urethritis in men, but is most often asymptomatic or occurs with minimal symptoms. It is associated with other STIs, adverse pregnancy outcomes and pelvic inflammatory disease. For these reasons, health care provider awareness of trichomoniasis is of public health importance.

Methods

To assess practitioner knowledge, attitudes, and practices concerning trichomoniasis management, the American College of Obstetricians and Gynecologists conducted an online survey in 2016 of its members, and we analyzed results from 230 respondents.

Results

We note discrepancies between practice and recommendations among surveyed providers: a minority of respondents routinely screen human immunodeficiency virus (HIV)-positive patients for trichomoniasis (10.7%, “most of the time”; 95% confidence interval [CI], 6.7–15.8; 33.0%, “always”; 95% CI, 26.5%–40.0%), treat trichomoniasis in HIV-positive patients with the recommended dose of metronidazole 500 mg twice a day for 7 days (25.8%; 95% CI, 20.0%–32.3%), or retest patients diagnosed with trichomoniasis 3 months after treatment (9.6%; 95% CI, 6.1%–14.3%). Only 29.0% (95% CI, 23.0%–35.5%) retreat with metronidazole 500 mg twice a day for 7 days in patients who have failed prior treatment.

Conclusions

Screening for and treatment of trichomoniasis in HIV-positive patients, and retesting and retreatment for trichomoniasis in the general population appear to be suboptimal. Continuing education for providers is needed for this common but “neglected” STI.

Antiparasitic activity of furanyl N-acylhydrazone derivatives against Trichomonas vaginalis: in vitro and in silico analyses

BACKGROUND

Trichomonas vaginalis is the causative agent of trichomoniasis, which is one of the most common sexually transmitted diseases worldwide. Trichomoniasis has a high incidence and prevalence and is associated with serious complications such as HIV transmission and acquisition, pelvic inflammatory disease and preterm birth. Although trichomoniasis is treated with oral metronidazole (MTZ), the number of strains resistant to this drug is increasing (2.5-9.6%), leading to treatment failure. Therefore, there is an urgent need to find alternative drugs to combat this disease.

METHODS

Herein, we report the in vitro and in silico analysis of 12 furanyl N-acylhydrazone derivatives (PFUR 4, a-k) against Trichomonas vaginalis. Trichomonas vaginalis ATCC 30236 isolate was treated with seven concentrations of these compounds to determine the minimum inhibitory concentration (MIC) and 50% inhibitory concentration (IC50). In addition, compounds that displayed anti-T. vaginalis activity were analyzed using thiobarbituric acid reactive substances (TBARS) assay and molecular docking. Cytotoxicity analysis was also performed in CHO-K1 cells.

RESULTS

The compounds PFUR 4a and 4b, at 6.25 µM, induced complete parasite death after 24 h of exposure with IC50 of 1.69 µM and 1.98 µM, respectively. The results showed that lipid peroxidation is not involved in parasite death. Molecular docking studies predicted strong interactions of PFUR 4a and 4b with T. vaginalis enzymes, purine nucleoside phosphorylase, and lactate dehydrogenase, while only PFUR 4b interacted in silico with thioredoxin reductase and methionine gamma-lyase. PFUR 4a and 4b led to a growth inhibition (< 20%) in CHO-K1 cells that was comparable to the drug of choice, with a promising selectivity index (> 7.4).

CONCLUSIONS

Our results showed that PFUR 4a and 4b are promising molecules that can be used for the development of new trichomonacidal agents for T. vaginalis.

Management of Resistant Trichomoniasis

PURPOSE OF REVIEW

Trichomonas vaginalis is the most prevalent sexually transmitted parasite in the USA; resistant infection is emerging. New drug therapies and dosing regimens of standard therapies are being studied to treat resistant infection.

RECENT FINDINGS

Diagnosis of trichomoniasis has become more sensitive, specific, and widely available with the advent of nucleic acid amplification tests (NAATs). Women with resistant trichomoniasis should be treated with high-dose regimens of metronidazole or tinidazole. Alternative treatment options have been described, and there has been some success particularly with high-dose tinidazole/intravaginal paromomycin cream combination, intravaginal boric acid, and intravaginal metronidazole/miconazole. Resistant trichomoniasis is a growing public health concern with implications for long-term health consequences. More data are needed to further evaluate mechanisms by which resistance occurs as well as promising therapies for those affected.

Prevalence and cervical organism burden among Louisiana women with Trichomonas vaginalis infections

Trichomonas vaginalis is the most common curable sexually transmitted infection (STI) worldwide. Although predominately asymptomatic, the disease spectrum of trichomoniasis in women is characterized primarily by signs and symptoms of vaginitis, including purulent discharge and localized vulvar pruritus and erythema. Several FDA-cleared nucleic acid amplification tests (NAATs) are available for the diagnosis of T. vaginalis infections, but laboratory developed tests (LDTs) are widely utilized and cost-effective solutions in both the research and clinical diagnostic settings. LDT diagnosis of T. vaginalis is particularly appealing since it can be performed using remnant specimens collected for other STI testing. Using a LDT implemented as part of this study, T. vaginalis was detected in 7% of participating Louisiana women (14/199). The mean T. vaginalis organism burden was 1.0x10⁶ ± 4.5x10⁵ organisms per mL of ThinPrep PreservCyt. Using DNA eluates obtained after HPV testing on the cobas 4800 system, the T. vaginalis LDT was characterized by excellent intra- and interassay reproducibility (coefficient of variation values all <3.5%). Compared with two commercially available NAATs from TIB MOLBIOL, the sensitivity and specificity of the LDT was 92.9 and 99.5%, respectively. Collectively, this study details the diagnostic and quantitative utility of a LDT for T. vaginalis. When applied in the clinical research setting, we confirmed the high prevalence of T. vaginalis, but also observed extraordinarily high organism burdens in the cervix. These findings highlight the unique host-pathogen relationship of T. vaginalis with lower reproductive tract tissues, and substantiate the need for continued investigation of this highly prevalent STI.

Screening for Trichomonas vaginalis in a Large High-Risk Population: Prevalence Among Men and Women Determined by Nucleic Acid Amplification Testing

A large sample (n = 77,740) of men and women tested for Trichomonas vaginalis showed increasing age-dependent infection rates for both sexes, suggesting that older men and older women should be screened for this sexually transmitted infection.

Men and women attending family planning and sexually transmitted disease clinics for sexually transmitted infection screening in 2012 to 2013 were tested for Trichomonas vaginalis (TV) using a sensitive nucleic acid amplification test. T. vaginalis prevalence in urogenital samples was 11.3% in 77,740 women and 6.1% in 12,604 men, and increased with age in both sexes.

PREVALENCE OF TRICHOMONIASIS IN ASYMPTOMATIC PREGNANT WOMEN POPULATION IN BANDUNG, WEST JAVA, INDONESIA

About 81% of pregnant women with trichomoniasis are asymptomatic, while trichomoniasis in pregnant women can increase the risk of complications, include premature rupture of membranes, preterm birth, and babies with low birth weight. Trichomoniasis can also increase the risk of other sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) transmission. Trichomoniasis case in pregnant women could be influenced by demographic characteristics,, the sexual behavior, and also the diagnostic method used. Until now, there is no data about prevalence of trichomoniasis in pregnant women in Indonesia. The aim of this research was to determine the prevalence of trichomoniasis in pregnant women in Bandung, West Java, Indonesia. A descriptive cross-sectional study was performed in December 2016 until January 2017. The study participants were 50 pregnant women who visit antenatal care to Obstetric and Gynecology Clinic of ’Rumah Sakit Khusus Ibu dan Anak Kota Bandung’, and meet the inclusion and exclusion criteria, through consecutive sampling. The study participants had a history taking, venereological examination, and Trichomonas rapid test from vaginal swabs. Trichomoniasis in this study was diagnosed based on Trichomonas rapid test, a test that uses color immunochromatographic, capillary flow, dipstick technology, and has high sensitivity and specificity in diagnosing trichomoniasis. Almost all participants in this study were low risk pregnant women to have STI based on demographic characteristics and sexual behaviour. The positive Trichomonas rapid test result was found from one of 50 study participants. In conclusion, prevalence of trichomoniasis in pregnant women in Bandung was 2%. Trichomoniasis case in low-risk pregnant women population is still found.

Trichomonas vaginalis Induces NLRP3 Inflammasome Activation and Pyroptotic Cell Death in Human Macrophages

Trichomonas vaginalis is a sexually transmitted, eukaryotic parasite that causes trichomoniasis, the most common nonviral, sexually transmitted disease in the USA and worldwide. Little is known about the molecular mechanisms involved in the host immune response to this widespread parasite. Here we report that T. vaginalis induces NLRP3 inflammasome activation in human macrophages, leading to caspase-1 activation and the processing of pro-IL-1β to the mature and bioactive form of the cytokine. Using inhibitor-based approaches, we show that NLRP3 activation by T. vaginalis involves host cell detection of extracellular ATP via P2X7 receptors and potassium efflux. In addition, our data reveal that T. vaginalis inflammasome activation induces macrophage inflammatory cell death by pyroptosis, known to occur via caspase-1 cleavage of the gasdermin D protein, which assembles to form pores in the host cell membrane. We found that T. vaginalis-induced cytolysis of macrophages is attenuated in gasdermin D knockout cells. Lastly, in a murine challenge model, we detected IL-1β production in vaginal fluids in response to T. vaginalis infection in vivo. Together, our findings mechanistically dissect how T. vaginalis contributes to the production of the proinflammatory IL-1β cytokine and uncover pyroptosis as a mechanism by which the parasite can trigger host macrophage cell death.

Chemotherapeutic options for the treatment of human trichomoniasis

Trichomonas vaginalis is the causative agent of the most common non-viral sexually transmitted disease worldwide. The infection may be associated with severe complications, including infertility, preterm labour, cancer and an increased risk of human immunodeficiency virus (HIV) transmission. Treatment remains almost exclusively based on 5-nitroimidazoles, but resistance is on the rise. This article provides an overview of clinically evaluated systemic and topical treatment options for human trichomoniasis and summarises the current state of knowledge on various herbal, semisynthetic and synthetic compounds evaluated for their anti-Trichomonas efficacy in vitro.

Single-dose versus 7-day-dose metronidazole for the treatment of trichomoniasis in women: an open-label, randomised controlled trial

BACKGROUND

Among women, trichomoniasis is the most common non-viral sexually transmitted infection worldwide, and is associated with serious reproductive morbidity, poor birth outcomes, and amplified HIV transmission. Single-dose metronidazole is the first-line treatment for trichomoniasis. However, bacterial vaginosis can alter treatment efficacy in HIV-infected women, and single-dose metronidazole treatment might not always clear infection. We compared single-dose metronidazole with a 7-day dose for the treatment of trichomoniasis among HIV-uninfected, non-pregnant women and tested whether efficacy was modified by bacterial vaginosis.

METHODS

In this multicentre, open-label, randomised controlled trial, participants were recruited at three sexual health clinics in the USA. We included women positive for Trichomonas vaginalis infection according to clinical screening. Participants were randomly assigned (1:1) to receive either a single dose of 2 g of metronidazole (single-dose group) or 500 mg of metronidazole twice daily for 7 days (7-day-dose group). The randomisation was done by blocks of four or six for each site. Patients and investigators were aware of treatment assignment. The primary outcome was T vaginalis infection by intention to treat, at test-of-cure 4 weeks after completion of treatment. The analysis of the primary outcome per nucleic acid amplification test or culture was also stratified by bacterial vaginosis status. This trial is registered with ClinicalTrials.gov, number NCT01018095, and with the US Food and Drug Administration, number IND118276, and is closed to accrual.

FINDINGS

Participants were recruited from Oct 6, 2014, to April 26, 2017. Of the 1028 patients assessed for eligibility, 623 women were randomly assigned to treatment groups (311 women in the single-dose group and 312 women in the 7-day-dose group; intention-to-treat population). Although planned enrolment had been 1664 women, the study was stopped early because of funding limitations. Patients in the 7-day-dose group were less likely to be T vaginalis positive at test-of-cure than those in the single-dose group (34 [11%] of 312 vs 58 [19%] of 311, relative risk 0·55, 95% CI 0·34-0·70; p<0·0001). Bacterial vaginosis status had no significant effect on relative risk (p=0·17). Self-reported adherence was 96% in the 7-day-dose group and 99% in the single-dose group. Side-effects were similar by group; the most common side-effect was nausea (124 [23%]), followed by headache (38 [7%]) and vomiting (19 [4%]).

INTERPRETATION

The 7-day-dose metronidazole should be the preferred treatment for trichomoniasis among women.

FUNDING

National Institutes of Health.

Higher vaginal pH in Trichomonas vaginalis infection with intermediate Nugent score in reproductive-age women-a hospital-based cross-sectional study in Odisha, India

A close association between Trichomonas vaginalis (TV) infection and bacterial vaginosis (BV) has been reported. Some other studies have found association is stronger with intermediate Nugent score than BV. Most studies have used wet mount microscopy, a relatively insensitive method, to detect TV infection. We wanted to study the association of TV infection with BV and with intermediate Nugent score. We undertook a cross-sectional hospital-based study of 1110 non-pregnant women from Odisha state, India, aged between 18 and 45 years, collecting vaginal swabs for diagnosis of BV by Nugent score (NS) criteria and TV by PCR analysis. TV infection was found in 13.3% of women with intermediate Nugent score (NS 4-6) and 13.6% with BV (NS 7-10). Before adjustment, TV infection was associated with BV, intermediate Nugent, vaginal pH ≥ 4.5, and age group between 26 and 35 years. Multivariate analysis confirmed that TV infection was more likely to have raised vaginal pH, either BV or intermediate Nugent. Proportion of TV cases increased sequentially with the increase in Nugent score up to NS 6, after which a decline was observed. Vaginal pH was higher in the TV-infected group than the uninfected group in women with intermediate Nugent, but no difference was noticed in women with BV. TV infection was equally prevalent in women with intermediate Nugent as well as BV. In the intermediate Nugent group women, TV infection was found only when vaginal pH was raised, indicating a crucial role of vaginal pH in determining TV infection.

Synthesis and Preliminary Antimicrobial Analysis of Isatin-Ferrocene and Isatin-Ferrocenyl Chalcone Conjugates

In this study, we outline the synthesis of isatin-ferrocenyl chalcone and 1H-1,2,3-triazole-tethered isatin-ferrocene conjugates along with their antimicrobial evaluation against the human mucosal pathogen Trichomonas vaginalis. The introduction of a triazole ring among the synthesized conjugates improved the activity profiles with most of the compounds in the library, exhibiting 100% growth inhibition in a preliminary susceptibility screen at 100 μM. IC₅₀ determination of the most potent compounds in the set revealed an inhibitory range between 2 and 13 μM. Normal flora microbiome are unaffected by these compounds, suggesting that these may be new chemical scaffolds for the discovery of new drugs against trichomonad infections.

Trichomonas vaginalis Prevalence and Correlates in Women and Men Attending STI Clinics in Western Canada

Trichomonas vaginalis prevalence (2.8%) in female sexually transmitted infection clinic attendees was within the prevalence of chlamydia (5.8%) and gonorrhea (1.8%), while being very low for male attendees (0.2%). Correlates among women were indigenous ethnicity, other ethnicity, and being symptomatic.

In Vitro Study of the Susceptibility of Clinical Isolates of Trichomonas vaginalis to Metronidazole and Secnidazole

Nitroimidazoles (metronidazole [MTZ] and tinidazole [TNZ]) are the only drugs recommended for treatment of Trichomonas vaginalis infections. MTZ resistance occurs in 4% to 10% of cases of vaginal trichomoniasis (R. D. Kirkcaldy et al., Emerg Infect Dis 18:939-943, 2012; J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006) and TNZ resistance in 1% of cases (J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006). Emerging nitroimidazole-resistant trichomoniasis is concerning, because few alternatives to standard therapy exist. We assessed the prevalence of in vitro aerobic MTZ and secnidazole resistance among T. vaginalis isolates collected in 2015 to 2016 from 100 women in Birmingham, Alabama, with positive cultures. Archived specimens were treated with secnidazole or MTZ (0.2 to 400 μg/ml) for 48 h, according to U.S. Centers for Disease Control and Prevention protocols. Ninety-six (96%) of the 100 clinical Trichomonas isolates tested demonstrated lower minimum lethal concentrations for secnidazole than for MTZ, suggesting that secnidazole has better in vitro activity than MTZ.

Impact of replacing cytology with human papillomavirus testing for cervical cancer screening on the prevalence of Trichomonas vaginalis: a modelling study

Objectives

Trichomonas vaginalis (TV) is the most common curable STI worldwide and is associated with increased risk of HIV acquisition and serious reproductive morbidities. The prevalence of TV infection is very low in Australian cities, and this is thought to be at least partly due to incidental detection and treatment of TV in women participating in the cervical cytology screening programme. In 2017, the national cervical screening programme will transition to a new model based on testing for high-risk (HR) human papillomavirus (HPV), with a reduced frequency and commencement at an older age. We model the potential impact of this transition on TV prevalence in Australia.

Methods

A mathematical model was developed to describe the transmission of TV in the general population and used to evaluate scenarios that capture the switch from cytology-based screening to HR HPV testing. Under these scenarios, individuals with asymptomatic TV who test negative for HR HPV will remain undiagnosed and untreated. We estimate the change in TV prevalence expected to occur due to the switch from cytology to HR HPV testing and changes to the frequency and age at commencement of screening.

Results

Our results suggest that with the transition to HR HPV testing, TV prevalence may increase from the current ~0.4% to 2.8% within 20 years if TV testing coverage is not increased and HR HPV prevalence does not decline further. If HR HPV prevalence continues to decline at its current rate with ongoing vaccination, TV prevalence is predicted to increase to 3.0% within this time frame.

Conclusions

Our modelling suggests that in a setting like Australia, where TV can be detected incidentally through cytology-based cervical screening, a transition to HPV testing is likely to result in increasing TV prevalence over time unless additional measures are implemented to increase TV testing and treatment.

Rapid Diagnosis of Trichomonas vaginalis by Testing Vaginal Swabs in an Isothermal Helicase-Dependent AmpliVue Assay

BACKGROUND

The AmpliVue Trichomonas Assay (Quidel) is a new Federal Drug Administration-cleared rapid test for qualitative detection of Trichomonas vaginalis (TV) DNA in female vaginal specimens. The assay is based on BioHelix's helicase-dependent amplification isothermal technology in conjunction with a disposable lateral-flow detection device, with a total turnaround time of approximately 45 minutes.

OBJECTIVE

The objective of this study was to compare the performance of this new assay to wet preparation and culture as well as to another Federal Drug Administration-cleared nucleic acid amplification assay.

METHODS

Four clinician collected vaginal swabs were obtained from women attending sexually transmitted disease, family planning, and OB/GYN clinics and tested by AmpliVue Trichomonas Assay and comparator tests: saline microscopy, TV culture (InPouch), and Aptima TV. AmpliVue Trichomonas Assay results were compared with a composite positive comparator (CPC) as determined by the results from culture and/or wet mount microscopic examination. At least one of either the wet preparation or culture reference test results was required to be positive to establish CPC.

RESULTS

A total of 992 patients, 342 symptomatic and 650 asymptomatic patients, were included in the study. Results for AmpliVue for all women combined compared with saline microscopy and culture as a CPC yielded a sensitivity of 100%. Specificity for all women was 98.2%. Overall percent agreement versus Aptima TV was 97.8%. Sensitivity for AmpliVue compared with Aptima was 90.7% %, whereas specificity was 98.9%.

CONCLUSIONS

The rapid AmpliVue Trichomonas Assay performed as well as microscopy and culture, and had comparable sensitivity and specificity to another nucleic acid amplification test for the detection of TV. This study provided evidence of new diagnostic options and indicated very good performance of amplified testing for detection of TV in symptomatic and asymptomatic women.

Adenosine reduces reactive oxygen species and interleukin-8 production by Trichomonas vaginalis-stimulated neutrophils

Trichomonas vaginalis is a flagellated protozoan that affects the human urogenital tract causing 276.4 million new infections a year. The parasite elicits a vaginal mucosal infiltration of immune cells, especially neutrophils which are considered to be primarily responsible for cytological change observed at the infection site as well as the major contributor in the inflammatory response against the parasite. Extracellular nucleotides and their nucleosides are signaling compounds involved in several biological processes, including inflammation and immune responses. Once in the extracellular space, the nucleotides and nucleosides can directly activate the purinergic receptors. Herein, we investigated the involvement of purinergic signaling on the production of reactive oxygen species (ROS) and cytokines by T. vaginalis-stimulated neutrophils. Parasites were able to induce an increase in ROS and IL-8 levels while they did not promote IL-6 secretion or neutrophil elastase activity. Adenine and guanine nucleotides or nucleosides were not able to modulate ROS and cytokine production; however, when T. vaginalis-stimulated neutrophils were incubated with adenosine and adenosine deaminase inhibitor, the levels of ROS and IL-8 were significantly reduced. These immunosuppressive effects were probably a response to the higher bioavailability of adenosine found in the supernatant as result of inhibition of enzyme activity. The involvement of P1 receptors was investigated by immunofluorescence and A1 receptor was the most abundant. Our data show that the influence of purinergic signaling, specifically those effects associated with adenosine accumulation, on the modulation of production of proinflammatory mediators by T. vaginalis-stimulated neutrophils contribute to the understanding of immunological aspects of trichomoniasis.

Rapid and point-of-care tests for the diagnosis of Trichomonas vaginalis in women and men

BACKGROUND

Trichomonasvaginalis (TV) is a highly prevalent parasitic infection worldwide. It is associated with many adverse reproductive health outcomes. Many infections are asymptomatic and syndromic management leads to underdetection of TV. Traditional methods of TV detection such as wet preparation are insensitive. New rapid, point-of-care (POC) tests can enhance the diagnosis of trichomoniasis.

METHODS

The authors reviewed the literature and discuss older POC tests for TV detection, as well as the OSOM lateral flow test, the AmpliVue test, the Solana test and the GeneXpert test as well as the limitations of wet preparation and culture for detection of TV.

RESULTS

The OSOM test is easy to perform, compared with other POC tests, and is Clinical Laboratory Improvement Amendments (CLIA)-waived, equipment-free, has sensitivities of 83%-86% compared with nucleic acid amplification tests (NAATs) and can be performed in 15 min. The AmpliVue and the Solana tests are not CLIA waived and require small pieces of equipment. They are molecular amplified assays and can be completed in <1 hour. AmpliVue demonstrated a sensitivity for vaginal swabs of 100% compared with wet preparation/culture and 90.7% compared with NAATs. Solana demonstrated a sensitivity of 98.6%-100% for vaginal swabs and 92.9%-98% for female urines, compared with wet preparation/culture. Compared with other NAATs, the sensitivity for Solana was 89.7% for swabs and 100% for urine. The GeneXpert TV test for women and men is a moderately complex test, requires a small platform and can be performed in <1 hour. The sensitivity compared with wet preparation/culture for self-collected vaginal swabs was 96.4%, 98.9% for endocervical specimens and 98.4% for female urine. For men, sensitivity for urines was excellent (97.2%). The specificity for all assays was excellent.

CONCLUSIONS

Several rapid POC tests have the potential to rapidly diagnose trichomoniasis in women and one is available for detection of TV in men.

Clinical performance of the Solana® Point-of-Care Trichomonas Assay from clinician-collected vaginal swabs and urine specimens from symptomatic and asymptomatic women

BACKGROUND

Solana® (Quidel) is a new rapid (<40 min.) point-of-care (POC) test for qualitative detection of Trichomonas vaginalis (TV) DNA. The assay has two steps: 1) specimen preparation, and 2) amplification and detection using isothermal Helicase-Dependent Amplification (HDA). The objective was to demonstrate the performance of Solana for vaginal swabs and female urines based on comparison to wet mount and TV culture. Performance was also compared to the Aptima-TV assay.

METHODS

Urine and four clinician-collected vaginal swabs were collected. The first two were used for FDA composite reference (wet mount; InPouch TV Culture). The third swab was used for Solana. Sensitivity/specificity were based on the reference method. A specimen was considered positive if either test was positive. The fourth swab was for Aptima-TV.

RESULTS

Vaginal swabs and urines were obtained from 501 asymptomatic and 543 symptomatic women. Prevalence of TV by was 11.5%. For swabs, Solana® demonstrated high sensitivity and specificity from asymptomatic (100%/98.9%) and symptomatic (98.6%/98.5%) women, as well as for urines from asymptomatic (98.0%/98.4%) and symptomatic (92.9%/97.9%) women, compared to the reference method. Compared to Aptima-TV, the sensitivity/specificity was 89.7%/99.0% for swabs and 100%/98.9% for urines.

CONCLUSION

The Solana® assay performed well compared to the reference assays.

Combined Testing for Chlamydia, Gonorrhea, and Trichomonas by Use of the BD Max CT/GC/TV Assay with Genitourinary Specimen Types

The BD Max CT/GC/TV (MAX) assay is a true multiplex assay for simultaneous detection of chlamydia (CT), gonorrhea (GC), and trichomonas (TV). We evaluated assay performance for women using endocervical and vaginal swabs as well as urine specimens. A total of 1,143 women were tested for CT, GC, and TV and, subsequently, another 847 (1,990 total women) for CT and GC only, with positivity rates for CT, GC, and TV of 7.1%, 2.3%, and 13.5%, respectively. In men, the performance for CT and GC was determined using only urine specimens. TV performance was not assessed in male urine samples. Among men, 181/830 (21.8%) and 108/840 (12.9%) chlamydia and gonorrhea infections, respectively, were identified. Comparator assays included BD ProbeTec Chlamydia trachomatis Qx (CTQ)/Neisseria gonorrhoeae Qx (GCQ), Hologic Aptima Combo 2 (AC2) and Aptima TV (ATV), trichomonas microscopy, and culture. MAX CT sensitivity was 99.3% (95% confidence interval [CI], 96.1% to 99.9%), 95.7% (90.8% to 98.0%), 91.5% (85.8% to 95.1%), and 96.1% (92.2% to 98.1%) for vaginal swabs, endocervical swabs, female urine samples, and male urine samples, respectively. MAX GC sensitivity was 95.5% (84.9% to 98.7%), 95.5% (84.9% to 98.7%), 95.7% (85.5% to 99.8%), and 99.1% (94.9% to 99.8%) in the same order. MAX TV sensitivity was 96.1% (91.7% to 98.2%) for vaginal swabs, 93.4% (88.3% to 96.4%) for endocervical swabs, and 92.9% (87.8% to 96.0%) for female urine samples. Specificity for all organisms across all sample types was ≥98.6%. Performance estimates for the MAX assays were consistent with estimates calculated for the comparator assays (all P values were >0.1). The availability of a CT/GC/TV multiplexed assay on a benchtop instrument with a broad menu has the potential to facilitate local sexually transmitted infection (STI) testing at smaller laboratories and may encourage expanded screening for these highly prevalent infections.

Trichomonas vaginalis and Human Immunodeficiency Virus Coinfection Among Women Under Community Supervision: A Call for Expanded T. vaginalis Screening

BACKGROUND

The United States has a large community supervision population, a growing number of whom are women. Trichomonas vaginalis infection is strongly associated with an increased risk of human immunodeficiency virus (HIV) acquisition and transmission, particularly among women, but there is a paucity of research on HIV and T. vaginalis co-infection among women under community supervision.

METHODS

This article examines the prevalence of T. vaginalis infection and T. vaginalis and HIV coinfection at baseline among women under community supervision in New York City. It also examines the 12-month outcomes of women treated for T. vaginalis. Women received biological tests for HIV and T. vaginalis at baseline and 12 months follow-up.

RESULTS

Of the 333 women tested for sexually transmitted infections, 77 women (23.1%) tested positive for T. vaginalis at baseline and 44 (13.3%) were HIV positive. Human immunodeficiency virus-positive women had significantly higher rates of T. vaginalis infection than HIV-negative women (36.4% vs 21.3%, P ≤ 0.05). Sixteen women (4.8%) were coinfected with T. vaginalis and HIV. Of the 77 women who were positive for T. vaginalis infection at baseline, 58 (75.3%) received treatment by a health care provider. Of those who received treatment, 17 (29.3%) tested positive for T. vaginalis at the 12-month follow-up.

CONCLUSIONS

Given the high prevalence of T. vaginalis among this sample of women, particularly among HIV-positive women, and high levels of reinfection or persistent infection, screening for T. vaginalis among women under community supervision may have a substantial impact on reducing HIV acquisition and transmission among this high-risk population.