Trichomonas vaginalis: pathogenicity and potential role in human reproductive failure

Investigation of the frequency and relationship between trichomonas infection in the preterm delivery (a case-control study in Amir Al-Momenin Hospital, Semnan)

Introduction and Purpose

Preterm delivery is a common complication during pregnancy periods and imposes a high cost on the healthcare system due to the care needs of premature babies. Sexually transmitted infections are one of the effective factors in the occurrence of preterm delivery and the diagnosis and treatment of these infections are effective in reducing complications and preventing preterm delivery. In this study, the role of Trichomonas vaginalis (T. vaginalis [TV]) infection in preterm delivery has been evaluated.

Methods

In a prospective case-control study, women with preterm birth were assigned to the case group, and women with full-term delivery on the same day were also assigned randomly to the control group. After receiving the history and physical examination, a sample was taken from the cervix for TV culture. The data were included in the SPSS version 23 software. A significance level of less than 0.05 was considered.

Findings

The overall prevalence of this infection was 10%. The prevalence of chlamydial infection was 2% among mothers with full-term delivery and 16.4% among mothers with premature birth, and there was a significant difference between the two groups (P = 0.021). The logistic regression analysis to determine the effect of Trichomonas infection on premature birth showed that there was the probability of the occurrence of premature delivery increases in mothers with trichomoniasis infection with lower age, higher body mass index, the presence of underlying disease, lower educational level, housewives, lower parity and gravity and having a history of fetus abortion more than 13 times with its occurrence probability occurs in mothers without Trichomonas infection (P = 0.046, Exp (β) =13.266).

Conclusion

According to the present results, TV screening for pregnant women, especially in high-risk groups, is emphasized to reduce the incidence of preterm delivery and related complications, especially neonatal complications.

Complement receptor 3 is required for maximum in vitro trogocytic killing of the parasite Trichomonas vaginalis by human neutrophil-like cells

Trichomonas vaginalis (Tv) is a parasite that causes trichomoniasis, a prevalent sexually-transmitted infection. Neutrophils are found at the site of infection, and can rapidly kill the parasite in vitro, using trogocytosis. However, the specific molecular players in neutrophil killing of Tv are unknown. Here, we show that complement proteins play a role in Tv killing by human neutrophil-like cells (NLCs). Using CRISPR/Cas9, we generated NLCs deficient in each of three complement receptors (CRs) known to be expressed on human neutrophils: CR1, CR3, and CR4. Using in vitro trogocytosis assays, we found that CR3, but not CR1 or CR4 is required for maximum trogocytosis of the parasite by NLCs, with NLCs lacking CR3 demonstrating ~40% reduction in trogocytosis, on average. We also observed a reduction in NLC killing of Tv in CR3 knockout, but not CR1 or CR4 knockout NLCs. On average, NLCs lacking CR3 had ~50% reduction in killing activity. We also used a parallel approach of pre-incubating NLCs with blocking antibodies against CR3, which similarly reduced NLC killing of parasites. These data support a model in which Tv is opsonized by the complement protein iC3b, and bound by neutrophil CR3 receptor, to facilitate trogocytic killing of the parasite.

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.

Clinical implications of trichomonads detected in bronchoalveolar fluid by metagenomic next-generation sequencing: a multicenter retrospective study

Background

Pulmonary trichomoniasis is considered a neglected disease due to failures in recognizing it, stemming from insensitive microbial methods and a lack of specific clinical features. This study aims to analyze the clinical implications of trichomonads detected in bronchoalveolar lavage fluid (BALF) by metagenomic next-generation sequencing (mNGS).

Methods

This multicenter retrospective study included patients diagnosed with pneumonia, admitted to three tertiary hospitals in China from July 2018 to September 2022, with trichomonads detected in BALF through mNGS. The analysis covered demographics, comorbidities, symptoms, laboratory findings, mNGS results, clinical treatment, and outcomes of these patients.

Results

A total of 17 patients were enrolled, comprising 14 males and 3 females. Trichomonas tenax and Trichomonas vaginalis were detected by mNGS in BALF samples of 15 and 2 patients, respectively. Patients were categorized into two groups based on the presence of risk factors for trichomonad infection, including immunocompromised conditions, uncontrolled diabetes mellitus, oral/periodontal diseases, and aspiration. Among 11 patients with risk factors (Case 1-11), 4 received nitromidazoles as part of comprehensive treatment, achieving a 100% treatment success rate. The remaining 7 patients, who did not receive nitromidazoles, had only one achieving relief after broad-spectrum antimicrobial therapy, resulting in a 14.3% treatment success rate. For the 6 patients without any risk factors for trichomonad infection (Case 12-17), none received nitromidazoles during hospitalization. However, 4 out of these 6 patients (66.7%) eventually recovered.

Conclusion

mNGS proves to be an efficient tool for detecting trichomonads in BALF samples. Comprehensive analysis of clinical features and laboratory indicators is essential to distinguish between infection and colonization of trichomonads. Pulmonary trichomoniasis should not be overlooked when trichomonads are detected in BALF from patients with risk factors.

Activity of compounds derived from benzofuroxan in Trichomonasvaginalis

Trichomoniasis is a sexually transmitted infection caused by the protozoan Trichomonas vaginalis. Currently, trichomoniasis is treated with the class of nitroimidazoles, namely, metronidazole; however, resistant isolates and strains have been reported. The compounds derived from benzofuroxan are biologically active heterocycles. This study evaluated the in vitro antiparasitic activity of these compounds in trophozoites of T. vaginalis and determined the mean inhibitory concentration (IC50), minimum inhibitory concentration (MIC), mortality curve, and cytotoxicity. The compounds were named EH1, EH2, EH3, and EA2 and tested in various concentrations: 100 to 15 μM (EH1 and EH2); 100 to 5 μM (EH3); and 100 to 25 μM (EA2), respectively. The greatest efficacy was observed in the highest concentrations in 24 h, with inhibition of approximately 100% of trophozoites. Compounds EH2 and EH3 had the lowest MIC: EH2 (35 μM) and EH3 (45 μM), with IC50 of 11.33 μM and 6.83 μM, respectively. Compound EA2 was effective at the highest concentrations. The activity of the compounds in T. vaginalis started in the first hour of incubation with 90% inhibition; after 12 h, inhibition >95% was observed. Compound EH1 showed the lowest activity, with the highest activity between 12 and 24 h after incubation. These results demonstrate that benzofuroxan derivatives are promising compounds for the in vitro treatment of T. vaginalis.

NlpC/P60 peptidoglycan hydrolases of Trichomonas vaginalis have complementary activities that empower the protozoan to control host-protective lactobacilli

Trichomonas vaginalis is a human protozoan parasite that causes trichomoniasis, a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a shift to a dysbiotic vaginal microbiome that is depleted of lactobacilli. Studies on co-cultures have shown that vaginal bacteria in eubiosis (e.g. Lactobacillus gasseri) have antagonistic effects on T. vaginalis pathogenesis, suggesting that the parasite might benefit from shaping the microbiome to dysbiosis (e.g. Gardnerella vaginalis among other anaerobes). We have recently shown that T. vaginalis has acquired NlpC/P60 genes from bacteria, expanding them to a repertoire of nine TvNlpC genes in two distinct clans, and that TvNlpCs of clan A are active against bacterial peptidoglycan. Here, we expand this characterization to TvNlpCs of clan B. In this study, we show that the clan organisation of NlpC/P60 genes is a feature of other species of Trichomonas, and that Histomonas meleagridis has sequences related to one clan. We characterized the 3D structure of TvNlpC_B3 alone and with the inhibitor E64 bound, probing the active site of these enzymes for the first time. Lastly, we demonstrated that TvNlpC_B3 and TvNlpC_B5 have complementary activities with the previously described TvNlpCs of clan A and that exogenous expression of these enzymes empower this mucosal parasite to take over populations of vaginal lactobacilli in mixed cultures. TvNlpC_B3 helps control populations of L. gasseri, but not of G. vaginalis, which action is partially inhibited by E64. This study is one of the first to show how enzymes produced by a mucosal protozoan parasite may contribute to a shift on the status of a microbiome, helping explain the link between trichomoniasis and vaginal dysbiosis. Further understanding of this process might have significant implications for treatments in the future.

Lactobacillus gasseri and Gardnerella vaginalis produce extracellular vesicles that contribute to the function of the vaginal microbiome and modulate host-Trichomonas vaginalis interactions

Trichomonas vaginalis is an extracellular protozoan parasite of the human urogenital tract, responsible for a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a dysbiotic microbiome that is characterised by the depletion of host-protective commensals such as Lactobacillus gasseri, and the flourishing of a bacterial consortium that is comparable to the one seen for bacterial vaginosis, including the founder species Gardnerella vaginalis. These two vaginal bacteria are known to have opposite effects on T. vaginalis pathogenicity. Studies on extracellular vesicles (EVs) have been focused on the direction of a microbial producer (commensal or pathogen) to a host recipient, and largely in the context of the gut microbiome. Here, taking advantage of the simplicity of the human cervicovaginal microbiome, we determined the molecular cargo of EVs produced by L. gasseri and G. vaginalis and examined how these vesicles modulate the interaction of T. vaginalis and host cells. We show that these EVs carry a specific cargo of proteins, which functions can be attributed to the opposite roles that these bacteria play in the vaginal biome. Furthermore, these bacterial EVs are delivered to host and protozoan cells, modulating host-pathogen interactions in a way that mimics the opposite effects that these bacteria have on T. vaginalis pathogenicity. This is the first study to describe side-by-side the protein composition of EVs produced by two bacteria belonging to the opposite spectrum of a microbiome and to demonstrate that these vesicles modulate the pathogenicity of a protozoan parasite. Such as in trichomoniasis, infections and dysbiosis co-occur frequently resulting in significant co-morbidities. Therefore, studies like this provide the knowledge for the development of antimicrobial therapies that aim to clear the infection while restoring a healthy microbiome.

Trichomonas vaginalis infection and risk of cervical neoplasia: A systematic review and meta-analysis

OBJECTIVES

The evidence in the literature regarding the relationship between Trichomonas vaginalis (TV) infection and cervical neoplasia is conflicting. The main aim of this study was to evaluate the magnitude of the risk of cervical neoplasia associated with TV infection.

METHODS

A meta-analysis of observational studies, which provided raw data on the association of TV infection with cervical neoplasia, was performed. For this aim, we searched scientific databases (PubMed/Medline, Scopus, the Web of Sciences, and Embase) from inception to March 15, 2023. A random-effects model was applied by Stata 17.0 to calculate the pooled and adjusted odds ratios (ORs) with 95% confidence intervals (CI), including subgroup, sensitivity, and cumulative analyses to explore sources of heterogeneity.

RESULTS

Of the 2584 records initially identified, 35 eligible studies contributed data for 67,856 women with cervical neoplasia, and 933,697 healthy controls from 14 countries were included. The pooled (2.15; 1.61-2.87; I2 = 87.7%) and adjusted (2.17; 1.82-2.60; I2 = 31.27%) ORs indicated a significant positive association between TV infection and the development of cervical neoplasia. There was no significant change in pooled and adjusted ORs by applying sensitivity and cumulative analyses, indicating the robustness of our findings. The pooled OR was significant in most sub-group analyses. There was no publication bias in the included studies.

CONCLUSION

Our findings indicated that women with a TV infection are at significantly greater risk of cervical neoplasia. Future research, particularly longitudinal and experimental studies, should be done to better understand the various aspects of this association.

Effects of SQ109 on Trichomonas vaginalis

Trichomonas vaginalis is a protozoan that causes human trichomoniasis, a sexually transmitted infection (STI) that affects approximately 278 million people worldwide. The current treatment for human trichomoniasis is based on 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, known as Metronidazole (MTZ). Although effective in eliminating parasitic infection, MTZ is related to serious adverse effects and is not recommended during pregnancy. In addition, some strains are resistant to 5'-nitroimidazoles, prompting the development of alternative drugs for trichomoniasis. Here we show that SQ109 [N-adamantan-2-yl-N'-((E)-3,7-dimethyl-octa- 2,6-dienyl)-ethane-1,2-diamine], a drug under development (antitubercular drug candidate that completed Phase IIb/III) for the treatment of tuberculosis, and previously tested in Trypanosoma cruzi and Leishmania. SQ109 inhibited T.vaginalis growth with an IC50 of 3.15 μM. We used scanning and transmission electron microscopy to visualize the ultrastructural alterations induced by SQ109. The microscopy analysis showed morphological changes on the protozoan surface, where the cells became rounded with increasing surface projections. In addition, the hydrogenosomes increased their size and area occupied in the cell. Furthermore, the volume and a significant association of glycogen particles with the organelle were seen to be altered. A bioinformatics search was done about the compound to find its possible targets and mechanisms of action. Our observations identify SQ109 as a promising compound against T. vaginalis in vitro, suggesting its potential utility as an alternative chemotherapy for trichomoniasis.

Trichomonas vaginalis excretory secretory proteins reduce semen quality and male fertility

Trichomonas vaginalis (T. vaginalis) infection is the most common non-viral sexually transmitted disease (STD) in the world. It can cause male reproductive dysfunction and infertility. However, the pathogenic mechanism is not clear. In this study, the excretory secretory proteins of T. vaginalis (TvESPs) were collected, concentrated, and sterilized. After sperm co-cultured with TvESPs, the survival rate and motility of sperms were analyzed by seminal routine examination, and the results showed that the TvESPs could significantly reduce the survival rate and motility of sperms. Fluorescence staining displayed that TvESPs could destroy the integrity of sperm acrosomes. Flow cytometry indicated that TvESPs induced sperm apoptosis. By mouse in vitro fertilization, we confirmed that TvESPs could significantly reduce the fertilization ability of sperms and negatively affect the development of the fertilized ovum. Via semi-quantitative analysis, we found that the apoptosis-related p27, SMAC, p53, BAX, BCL-2, XIAP, and BCL-W molecules were down-regulated in mouse sperm cells after interaction between the sperms and TvESPs, which played an important role in regulating sperm apoptosis. In conclusion, our study showed that T. vaginalis degraded semen quality and negatively affected male fertility by TvESPs. TvESPs may damage sperms by breaking the balance between sperm pro-apoptotic and anti-apoptotic molecules. This study proves that T. vaginalis infection is a risk factor for infertility.

Prevalence and Genotype of Trichomonas vaginalis among Men in Xinxiang City, Henan Province, China

Trichomonas vaginalis (T. vaginalis) could cause trichomoniasis through sexual transmission, which was globally distributed. In this study, the prevalence and phylogenetic analyses of T. vaginalis among men in Xinxiang were conducted. From October 2018 to December 2019, a total of 634 male clinical samples were collected, including 254 samples of semen, 43 samples of prostate fluid, and 337 samples of urine. These samples were examined by nested PCR and a total of 32 (5.05%) T. vaginalis-positive samples were detected. Among these samples, the positive rates of T. vaginalis in semen, prostate fluid, and urine were 7.87% (20/254), 4.65% (2/43), and 2.97% (10/337), respectively. Three actin genes were successfully isolated and sequenced from the 32 positive DNA samples, and the analysis of the sequence and phylogenetic tree showed that the three actin gene sequences exhibited 99.7%-100% homology to the published actin gene sequence (EU076580) in NCBI, and the T. vaginalis strains in the three positive samples were identified as genotype E. Our results demonstrate a notable genotype of T. vaginalis in the male population and provide insight into the performance of these genetic markers in the molecular epidemiology of trichomoniasis. However, further studies are needed to research the association between the genotype and the pathogenicity of T. vaginalis.

Development and validation of a predictive model for the risk of developing trichomonas vaginitis in women

Trichomonas vaginitis (TV) is the most common non-viral sexually transmitted infection (STI) worldwide. The high prevalence of TV combined with mild or asymptomatic early symptoms leads to clinical vulnerability from delayed diagnosis. Latent infection can increase the incidence of pelvic infections, infertility, and adverse pregnancy complications. Data from 898 women who underwent vaginal flora testing from June 2014 to December 2014 were used to create a nomogram to assess the risk of TV in women in order to guide TV prevention and clinical intervention. The prediction model was evaluated in terms of identification, calibration, and clinical utility using the C-index, calibration plots, decision curve analysis, and internal validation. Predictors in the TV nomogram included age, occupation, yearly income, tea drinking, bathing frequency, menopause, spontaneous abortion, use of contraceptives, history of gynecological surgery, and HPV infection. The C-index of the TV risk prediction model was 0.732 (95% confidence interval: 0.695-0.768). It showed good discriminatory and predictive power. Decision curve analysis indicated that the nomogram had a good net benefit when the threshold probability of TV in women was 2-80%. The established TV prediction model easily, accurately, and quickly predicts the risk of TV onset.

Prevalence of selected sexually transmitted infectious agents in a cohort of asymptomatic soldiers in Austria

BACKGROUND

According to the World Health Organization (WHO), more than one million sexually transmitted infections (STIs) are acquired every day worldwide. Although STIs may be asymptomatic in many cases, they can cause severe symptoms and can also lead to adverse pregnancy outcomes and both male and female infertility. Asymptomatic carriers seem to play an important role in terms of the distribution of STIs; however, studies revealing the prevalence of STIs in asymptomatic individuals are rare.

METHODS

In the current study, 654 leftovers of standard urine samples from healthy, asymptomatic Austrian soldiers were investigated for the prevalence of Trichomonas vaginalis, Chlamydia trachomatis, and genital mycoplasmas (Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Ureaplasma parvum, and Candidatus Mycoplasma girerdii) by specific PCRs.

RESULTS

We detected T. vaginalis, M. hominis, U. urealyticum, U. parvum, and C. trachomatis in the investigated samples with prevalence of 7.6%, 4%, 2.4%, 5.4%, and 3.2%, respectively; neither M. genitalium nor Ca. Mycoplasma girerdii was found in our sample collection.

CONCLUSIONS

Our study introduces data on STIs of a mainly male cohort, which are scarce because most of the available information on sexually transmitted infectious agents arises from fertility clinics (mainly women) or symptomatic patients.

Lactobacilli, a Weapon to Counteract Pathogens through the Inhibition of Their Virulence Factors

To date, several studies have reported an alarming increase in pathogen resistance to current antibiotic therapies and treatments. Therefore, the search for effective alternatives to counter their spread and the onset of infections is becoming increasingly important.

Identification of the Constituents in Cnidii Fructus Active Against Trichomonas vaginalis Parasites

Ethanol extracts of Cnidii Fructus, the dried fruits of Cnidium monnieri (L.) Cusson, have been externally applied in the treatment of Trichomonas vaginalis. However, the precise identity of the major constituents responsible for activity against T. vaginalis is unknown, but there is probability they are coumarin derivatives. In this study, the anti-Trichomonas activity of 4 major coumarin derivative constituents of Cnidii Fructus, namely, osthole, xanthotoxin, isopimpinellin, and bergapten, was characterized in terms of the resulting kinetics of growth and morphology of T. vaginalis upon treatment. The results demonstrated that osthole and xanthotoxol had significant trichomonacidal ability, while isopimpinellin and bergapten displayed low or no inhibitory efficacy toward T. vaginalis parasites. Our study suggests that the coumarin derivatives osthole and xanthotoxol can be potentially used as a basis for the development and design of new drugs for application in alternative or synergistic therapy against T. vaginalis.

Excretory-Secretory Products of Trichomonas vaginalis Cause Apoptosis in Mouse Sperm in Vitro

Excretory-secretory products (ESP) of T. vaginalis have been shown to inhibit sperm motility, viability, and functional integrity, leading to a decreased fertilization rate in vitro. This study investigated whether T. vaginalis induce apoptosis and ultrastructural changes of sperm using flow cytometry and electron microscopy. Incubation of sperm with T. vaginalis ESP increased phosphatidylserine externalization and DNA fragmentation, and decreased mitochondrial membrane potential. Transmission electron microscopy of sperm incubated with ESP revealed abnormal features such as distorted heads, broken necks, and acrosomes exocytosis. This is the first report that demonstrates a direct impact of T. vaginalis ESP on sperm apoptosis and architecture in vitro.

A systematic review of the correlation between Trichomonas vaginalis infection and infertility

BACKGROUND

Trichomonas vaginalis (T. vaginalis) is an extracellular flagellated protozoan parasitizing the human genital and urinary tracts. T. vaginalis infection impacts human reproductive function, but whether it causes infertility is still a matter of debate.

METHODS

In this work, we consulted 205 relevant articles, which were classified into three categories: epidemiological investigations (100), review articles (43), and research articles (62). RevMan 5.4 was used to conduct a meta-analysis of the articles reporting epidemiological investigations comparing the incidence of T. vaginalis infection between infertile and fertile groups. Review and research articles were used to summarize the pathogenesis of infertility caused by T. vaginalis.

RESULTS

The results indicated that rate of T. vaginalis infection in the infertile group was significantly higher than that in the fertile group. Moreover, the epidemiological surveys showed that the infertility rates of population infected with T. vaginalis were significantly higher than that of population without T. vaginalis infection. Nine out of ten (90%) related review articles stated that T. vaginalis infection causes infertility, and the review and research articles indicated the main pathogenic mechanisms of infertility caused by T. vaginalis were as follows: T. vaginalis impairs sperm quality, resulting in infertility; the immune response triggered by T. vaginalis infection impacts human reproductive function.

CONCLUSION

Our results confirm that there is a correlation between T. vaginalis infection and infertility, and T. vaginalis infection can lead to infertility. The study provides a foundation for further investigations into its pathogenesis.

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.

An Overview of Mucosa-Associated Protozoa: Challenges in Chemotherapy and Future Perspectives

Parasitic infections caused by protozoans that infect the mucosal surfaces are widely neglected worldwide. Collectively, Entamoeba histolytica, Giardia lamblia, Cryptosporidium spp. and Trichomonas vaginalis infect more than a billion people in the world, being a public health problem mainly in developing countries. However, the exact incidence and prevalence data depend on the population examined. These parasites ultimately cause pathologies that culminate in liver abscesses, malabsorption syndrome, vaginitis, and urethritis, respectively. Despite this, the antimicrobial agents currently used to treat these diseases are limited and often associated with adverse side effects and refractory cases due to the development of resistant parasites. The paucity of drug treatments, absence of vaccines and increasing problems of drug resistance are major concerns for their control and eradication. Herein, potential candidates are reviewed with the overall aim of determining the knowledge gaps and suggest future perspectives for research. This review focuses on this public health problem and focuses on the progress of drug repositioning as a potential strategy for the treatment of mucosal parasites.

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.

Trichomonas vaginalis triggers neutrophil extracellular traps reducing parasite integrity and growth

Trichomoniasis-caused by the parasite Trichomonas vaginalis-is associated with a high inflammatory process that may contribute to the risk of suffering from other medical complications. Our study focused on the in vitro interaction of T. vaginalis with human neutrophils because these are the most abundant cells implicated in the characteristic inflammatory process of trichomoniasis. This study showed that T. vaginalis and its surface glycoconjugates (lipophosphoglycan and/or lipoglycan) induced the formation of human neutrophil extracellular traps (NETs). After the trichomonad-neutrophil interaction, parasite integrity was at 32.9%, and the subsequent parasite growth was at 35.2% compared to those of control trophozoites (100%) incubated under the same conditions without neutrophils. In the presence of an antibody against the TLR-4 receptor, DNase I or micrococcal nuclease (MNase), neutrophils reduced the DNA fibres of the NETs and the amount of extracellular DNA, allowing a higher subsequent growth of T. vaginalis, at 52% with the anti-TLR-4 antibody and 62.6% with the enzymes. These results indicated that T. vaginalis induced the formation of extracellular traps by human neutrophils and, because of the interaction with neutrophils and NETs, parasite integrity and growth decreased.

Thio- and selenosemicarbazones as antiprotozoal agents against Trypanosoma cruzi and Trichomonas vaginalis

Herein, we report the preparation of a panel of Schiff bases analogues as antiprotozoal agents by modification of the stereoelectronic effects of the substituents on N-1 and N-4 and the nature of the chalcogen atom (S, Se). These compounds were evaluated towards Trypanosoma cruzi and Trichomonas vaginalis. Thiosemicarbazide 31 showed the best trypanocidal profile (epimastigotes), similar to benznidazole (BZ): IC₅₀ (31)=28.72 μM (CL-B5 strain) and 33.65 μM (Y strain), IC₅₀ (BZ)=25.31 μM (CL-B5) and 22.73 μM (Y); it lacked toxicity over mammalian cells (CC₅₀ > 256 µM). Thiosemicarbazones 49, 51 and 63 showed remarkable trichomonacidal effects (IC₅₀ =16.39, 14.84 and 14.89 µM) and no unspecific cytotoxicity towards Vero cells (CC₅₀ ≥ 275 µM). Selenoisosters 74 and 75 presented a slightly enhanced activity (IC₅₀=11.10 and 11.02 µM, respectively). Hydrogenosome membrane potential and structural changes were analysed to get more insight into the trichomonacidal mechanism.

Deep Learning for Microscopic Examination of Protozoan Parasites

The infectious and parasitic diseases represent a major threat to public health and are among the main causes of morbidity and mortality. The complex and divergent life cycles of parasites present major difficulties associated with the diagnosis of these organisms by microscopic examination. Deep learning has shown extraordinary performance in biomedical image analysis including various parasites diagnosis in the past few years. Here we summarize advances of deep learning in the field of protozoan parasites microscopic examination, focusing on publicly available microscopic image datasets of protozoan parasites. In the end, we summarize the challenges and future trends, which deep learning faces in protozoan parasite diagnosis.

Mycoplasma genitalium Provokes Seminal Inflammation among Infertile Males

The impact of sexually transmitted infections (STI) on male fertility is controversial. Aims: To investigate the prevalence of urethritis-associated STIs (chlamydia, gonorrhoeae, Mycoplasma genitalium, trichomoniasis) among infertile males; to analyze the effect of STIs on semen parameters and blood PSA. Case-control study. Study group (n = 2000): males with fertility problems or desire for fertility check. Control group (n = 248): male partners of pregnant women. Analyses: polymerase chain reaction for STI, seminal interleukin 6 (IL-6), semen and fractionated urine, blood analyses (PSA, reproductive hormones). The prevalence of M. genitalium and chlamydia in the study group was 1.1% and 1.2%, respectively. The prevalence of chlamydia in the control group was 1.6%, while there were no M. genitalium cases. No cases with gonorrhoeae or trichomoniasis or combined infections were observed in neither group. There was a higher seminal concentration of neutrophils and IL-6 among M. genitalium positives compared with STI negatives. There was a trend toward a lower total count of spermatozoa and progressive motility among STI positives. No impact of STIs on PSA was found. The prevalence of STIs among infertile males is low. M. genitalium is associated with seminal inflammation. The impact of STIs on semen parameters deserves further investigations.

E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates. In mammals, NTPDases have been implicated in the regulation of thrombosis and inflammation. In parasites, such as Trichomonas vaginalis, Trypanosoma spp., Leishmania spp., Schistosoma spp. and Toxoplasma gondii, NTPDases were found on the surface of the cell, and important processes like growth, infectivity, and virulence seem to depend on their activity. For instance, experimental evidence has indicated that parasite NTPDases can regulate the levels of ATP and Adenosine (Ado) of the host cell, leading to the modulation of the host immune response. In this work, we provide a comprehensive review showing the involvement of the nucleotidases/NTPDases in parasites infectivity and virulence, and how inhibition of NTPDases contributes to parasite clearance and the development of new antiparasitic drugs.

Bacterial Vaginosis and Its Association With Incident Trichomonas vaginalis Infections: A Systematic Review and Meta-Analysis

BACKGROUND

Bacterial vaginosis (BV) has been associated with an increased risk for acquisition of human immunodeficiency virus and sexually transmitted infections. We evaluated the association between BV and incident Trichomonas vaginalis (TV) infection in women.

METHODS

MEDLINE and ClinicalTrials.gov were searched for articles published between January 1, 1980, and May 7, 2021. Observational studies in women that evaluated the relationship between having/not having BV and the risk for acquiring TV were included.

RESULTS

Fourteen studies were included in the systematic review; 12 studies were included in meta-analyses involving 18,424 participants. Most studies used Nugent scoring to diagnose BV. For TV diagnosis, 12 studies used wet mount microscopy or culture, and 2 used nucleic acid amplification tests. There was diversity in the measures of association used, so an overall effect size could not be calculated. The majority of studies reported odds ratios, which showed an increased risk of incident TV among women with BV versus without BV (adjusted odds ratio, 1.87; 95% confidence interval, 1.45-2.40; P = 0.007). However, there were heterogeneity and potential confounding factors (eg, age, sexual partners) reported among studies.

CONCLUSIONS

This systematic review and meta-analysis provide evidence for a nearly 2-fold higher risk for acquiring TV among women with BV compared with women without BV.

Trichomonas vaginalis follow-up and persistence in Colombian women

Trichomonas vaginalis (TV), the most common non-viral sexually-transmitted infection is considered a neglected infection and its epidemiology is not well known. This study determined TV-infection dynamics in a retrospective cohort of Colombian women and evaluated associations between risk factors and TV-outcome. TV was identified by PCR. Cox proportional risk models were used for evaluating the relationship between TV-outcome (infection, clearance and persistence) and risk factors (sexually-transmitted infections and sociodemographic characteristics). Two hundred and sixty-four women were included in the study; 26.1% had TV at the start of the study, 40.9% suffered at least one episode of infection and 13.0% suffered more than one episode of TV during the study. Women suffering HPV had a greater risk of TV-infection (aHR 1.59), high viral-load (> 10²) for HPV-16 being related to a greater risk of persistent parasite infection; a high viral load (> 10²) for HPV-18 and -33 was related to a lower probability of TV-clearance. Ethnicity (afrodescendent/indigenous people: aHR 5.11) and having had more than two sexual partners (aHR 1.94) were related to greater risk of infection, contrasting with women having a background of abortions and lower probability of having TV (aHR 0.50). Women aged 35- to 49-years-old (aHR 2.08), increased years of sexual activity (aHR 1.10), multiple sexual partners (aHR 8.86) and multiparous women (aHR 3.85) led to a greater probability of persistence. Women whose cervical findings worsened had a 9.99 greater probability of TV-persistence. TV distribution was high in the study population; its coexistence with HPV and other risk factors influenced parasite infection dynamics. The results suggested that routine TV detection should be considered regarding populations at risk of infection.

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.

Efficacy and Safety of Single Oral Dosing of Secnidazole for Trichomoniasis in Women: Results of a Phase 3, Randomized, Double-Blind, Placebo-Controlled, Delayed-Treatment Study

Background

Trichomonas vaginalis is the most prevalent nonviral sexually transmitted infection. We evaluated the efficacy and safety of secnidazole vs placebo in women with trichomoniasis.

Methods

Women with trichomoniasis, confirmed by a positive T. vaginalis culture, were randomized to single-dose oral secnidazole 2 g or placebo. The primary endpoint was microbiological test of cure (TOC) by culture 6–12 days after dosing. At the TOC visit, participants were given the opposite treatment. They were followed for resolution of infection afterward and offered treatment at subsequent visits, if needed. Fifty patients per group (N = 100) provided approximately 95% power to detect a statistically significant difference between treatment groups.

Results

Between April 2019 and March 2020, 147 women enrolled at 10 sites in the United States. The modified intention-to-treat (mITT) population included 131 randomized patients (secnidazole, n = 64; placebo, n = 67). Cure rates were significantly higher in the secnidazole vs placebo group for the mITT population (92.2% [95% confidence interval {CI}: 82.7%–97.4%] vs 1.5% [95% CI: .0%–8.0%]) and for the per-protocol population (94.9% [95% CI: 85.9%–98.9%] vs 1.7% [95% CI: .0%–8.9%]). Cure rates were 100% (4/4) in women with human immunodeficiency virus (HIV) and 95.2% (20/21) in women with bacterial vaginosis (BV). Secnidazole was generally well tolerated. The most frequently reported treatment-emergent adverse events (TEAEs) were vulvovaginal candidiasis and nausea (each 2.7%). No serious TEAEs were observed.

Conclusions

A single oral 2 g dose of secnidazole was associated with significantly higher microbiological cure rates vs placebo, supporting a role for secnidazole in treating women with trichomoniasis, including those with HIV and/or BV.

Clinical Trials Registration

NCT03935217.

Long-term consequences of sexually transmitted infections on men's sexual function: A systematic review

Objective: To systematically review the available literature on the long-term effects of sexually transmitted diseases (STIs) on male reproductive functions.

Methods: A PubMed search was conducted on 3 January 2021, and as a result, 952 articles were retrieved. Exclusion of irrelevant articles resulted in 36 articles, dating from 1998 to 2020, which were analysed.

Results: Only 52.8% of these articles described original research, while the rest were reviews. The majority (26) of the articles dealt with bacterial infections, of which 20 described Chlamydia trachomatis. There were 11 articles that described research on viruses, with five on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The analysis of the articles showed further that not much new knowledge on the long-term effects on male reproductive functions has been added. The existing knowledge that ascending infections can cause epididymo-orchitis, prostatitis or urethritis was confirmed. Due to epithelial inflammatory responses these infections can result in scarring with resulting infertility due to obstruction. These effects were described for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium or Treponema pallidum, as well as for the Zika and SARS-CoV-2 viruses. Even trichomoniasis can lead to long-term compromised male fertility if not treated.

Conclusion: In conclusion, problem awareness needs to be raised and more research on this important topic needs to be conducted.

A review on Trichomonas vaginalis infections in women from Africa

Background

Trichomoniasis is the most common sexually transmitted infection (STI) with an estimated annual incidence of 276.4 million cases globally and about 30 million cases in sub-Saharan Africa. Trichomoniasis has been found to be associated with various health complications including pelvic inflammatory disease (PID), significant pregnancy complications, cervical cancer, prostatitis, infertility and the acquisition of human immunodeficiency virus (HIV).

Aim

Despite being a highly prevalent infection in the African continent, there is no review article published that solely focusses on Trichomonas vaginalis (T. vaginalis) infections in women from Africa. This review aims to fill this gap in the literature.

Method

An electronic search of online databases was used to identify and extract relevant research articles related to the epidemiology, health complications and treatment associated with T. vaginalis in women from Africa.

Results

Within the African continent, South Africa has reported the highest prevalence rate for this infection. A combination of sociodemographic, behavioural and biological factors has been shown to be associated with infection. Trichomonas vaginalis infection is associated with the acquisition of HIV, cervical cancer and PIDs in various female populations across the continent. Emerging patterns of resistance to metronidazole have been reported in women from South Africa. Currently, there is no effective vaccine against this pathogen despite efforts at vaccine development.

Conclusion

Based on the high prevalence and health consequences associated with T. vaginalis, there is a need for improved screening programmes that will lead to early diagnosis, detection of asymptomatic infections and effective treatment regimens.

Smooth muscle actin immunostain is useful for the diagnosis of Trichomonas vaginalis in vaginal smears

OBJECTIVE

The parasite Trichomonas vaginalis (T. vaginalis) causes one of the most common non-viral sexually transmitted infections in humans. T. vaginalis is notorious for its inconspicuous appearance in vaginal smears. It can be missed under the microscope.

METHOD

In the present study, we investigate the immunoreactivity of T. vaginalis to smooth muscle actin (SMA) in the vaginal smear.

RESULT

T. vaginalis trophozoite and pseduocyst are immunoreactive for SMA in all of the study group cases (n = 21) and in none of the control group cases (n = 21). Thus, SMA immunostain is a sensitive method for the demonstration of T. vaginalis. Moreover, the protozoan attains a conspicuous and unique appearance. By SMA immunohistochemical stain, the apperance of T. vaginalis floated freely or located in the cytoplasm of the epithelial cells is easily identified.

CONCLUSION

We recommend performing SMA immunostain in every vaginal smear with clinical or pathologic suspicion of trichomoniasis.

The Role of Purinergic Signaling in Trichomonas vaginalis Infection

Trichomoniasis, one of the most common non-viral sexually transmitted infections worldwide, is caused by the parasite Trichomonas vaginalis. The pathogen colonizes the human urogenital tract, and the infection is associated with complications such as adverse pregnancy outcomes, cervical cancer, and an increase in HIV transmission. The mechanisms of pathogenicity are multifactorial, and controlling immune responses is essential for infection maintenance. Extracellular purine nucleotides are released by cells in physiological and pathological conditions, and they are hydrolyzed by enzymes called ecto-nucleotidases. The cellular effects of nucleotides and nucleosides occur via binding to purinoceptors, or through the uptake by nucleoside transporters. Altogether, enzymes, receptors and transporters constitute the purinergic signaling, a cellular network that regulates several effects in practically all systems including mammals, helminths, protozoa, bacteria, and fungi. In this context, this review updates the data on purinergic signaling involved in T. vaginalis biology and interaction with host cells, focusing on the characterization of ecto-nucleotidases and on purine salvage pathways. The implications of the final products, the nucleosides adenosine and guanosine, for human neutrophil response and vaginal epithelial cell damage reveal the purinergic signaling as a potential new mechanism for alternative drug targets.

Global prevalence of Trichomonas vaginalis among female sex workers: a systematic review and meta-analysis

Trichomoniasis is a sexually transmitted infection (STI), caused by the protozoan parasite, Trichomonas vaginalis. Female sex workers are intensely affected by the infection, since they have frequent direct physical contact. The current systematic review and meta-analysis represents the global prevalence of T. vaginalis in female sex workers. Five databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar) were explored for literatures that published from July 1985 to June 2020. Totally, 85 studies (54,515 participants) from 46 countries met the inclusion criteria. The global pooled prevalence of T. vaginalis was 16% (95% CI 13-19%). The estimated pooled prevalence based on methods including wet mount, culture, and molecular techniques was 15% (95% CI 12-19%), 16% (95% CI 10-24%), and 22% (95% CI 13-32%), respectively. Moreover, the infection was most prevalent at the mean age of 30-36 (20%, 95% CI 11-30%). Regarding the World Health Organization (WHO) regions, the highest pooled prevalence was estimated to be in the African region (23%, 95% CI 7-46%). In addition, we indicated that countries with low-income level have the highest pooled prevalence (23%, 95% CI 14-34%). Our results revealed that the worldwide prevalence of T. vaginalis was significant in female sex workers. Therefore, considering a precise strategy such as a health education program with regard to safe intercourse is needed to increase knowledge and prevent T. vaginalis infection in sex workers.

Agents causing genital infections in routine cytological tests: frequency and characteristics of Papanicolaou smears

Urinary tract infections are responsible for most human infections, these are caused by bacteria, fungi, protozoa and associated microorganisms. The goal of this study was to determine the rate of vaginal infection-causing agents in routine cytological exams and also to evaluate the characteristics of positive tested Pap smears. A retrospective documental with descriptive aspect research was performed in a Clinical Pathology laboratory from Maceió-AL. The results of the Pap smears exams for Trichomonas vaginalis, Gardnerella vaginalis, Candida spp and HPV were arranged in a database as well as other data such as bacterial, protozoan, fungal and viral coinfections. The sample was composed by 18.645 women who have undergone Pap smear exams from 2013 to 2017. Of these analyzed exams, 27.4% in 2013, 10.9% in 2014, 10.6% in 2015, 15.2% in 2016 and 13.67% in 2017 were within normal range, however more than half of these exams presented some infections caused by unspecific or microbiological agents. By analyzing all the reports, 4.073 (21.84%) presented inflammations caused by some species of infectious agent with the following rate order: G. vaginalis and T. vaginalis. Furthermore, it was possible to confirm high rates of coinfection by and Candida spp. The rate of genital infections in this study highlights that there is a public health matter that must be controlled, which points a greater need for monitoring, guidance and actions towards greater awareness in order to prevent these problems.

Trichomoniasis and adverse birth outcomes: a systematic review and meta-analysis

BACKGROUND

Trichomoniasis commonly affects women of childbearing age and has been linked to several adverse birth outcomes.

OBJECTIVE

To elucidate the association between trichomoniasis in pregnant women and adverse birth outcomes, including preterm delivery, prelabour rupture of membranes and low birthweight.

SEARCH STRATEGY

MEDLINE, EMBASE and ClinicalTrials.gov were systematically searched in December 2020 without time or language restrictions.

SELECTION CRITERIA

Original research studies were included if they assessed at least one of the specified adverse birth outcomes in pregnant women with laboratory-diagnosed trichomoniasis.

DATA COLLECTION AND ANALYSIS

Estimates from included articles were either extracted or calculated and then pooled to produce a combined estimate of the association of trichomoniasis with each adverse birth outcome using the random effects model. Heterogeneity was assessed using the I² statistic and Cochran's Q test.

MAIN RESULTS

Literature search produced 1658 publications after removal of duplicates (n = 770), with five additional publications identified by hand search. After screening titles and abstracts for relevance, full text of 84 studies was reviewed and 19 met inclusion criteria for meta-analysis. Significant associations were found between trichomoniasis and preterm delivery (OR 1.27; 95% CI 1.08-1.50), prelabour rupture of membranes (OR 1.87; 95% CI 1.53-2.29) and low birthweight (OR 2.12; 95% CI 1.15-3.91).

CONCLUSIONS

Trichomoniasis in pregnant women is associated with preterm delivery, prelabour rupture of membranes and low birthweight. Rigorous studies are needed to determine the impact of universal trichomoniasis screening and treatment during pregnancy on reducing perinatal morbidity.

TWEETABLE ABSTRACT

This systematic review and meta-analysis found that in the setting of pregnancy, trichomoniasis is significantly associated with multiple adverse birth outcomes, including preterm delivery, low birthweight, and prelabour rupture of membranes.

Distribution of genotypes in relation to metronidazole susceptibility patterns in Trichomonas vaginalis isolated from South African pregnant women

Reports on metronidazole resistance of Trichomonas vaginalis strains have been on the increase. This study investigated the in vitro metronidazole resistance patterns in T. vaginalis isolates obtained from South African pregnant women and the genotypes of these isolates. This study included 362 pregnant women recruited from a hospital in Durban, South Africa. The women provided self-collected vaginal swabs for the detection of T. vaginalis by culture in Diamonds media. Cultured isolates were then subjected to anaerobic susceptibility assays to metronidazole. For the genotyping assays, the actin gene was digested by HindII, MseI, and RsaI. The banding patterns obtained after digestion was used to determine the genotypes. A total of 21/362 (5.8%) pregnant women tested positive for T. vaginalis infection. Of the 21 T. vaginalis isolates tested for metronidazole susceptibility, 9.5% (2/21) had a minimum inhibitory concentration (MIC) of 4 μg/ml (resistant), 38.1% (8/21) had a MIC of 2 μg/ml (intermediate), and 52.4% (11/21) had a MIC ≤ 1 μg/ml (susceptible). The dominant genotype that was identified across the isolates was genotype G. There was no correlation between genotype harboured and metronidazole susceptibility patterns. In this study, resistance to metronidazole was observed in clinical isolates of T. vaginalis. This study did not find a correlation between genotype harboured and metronidazole susceptibility patterns. Despite the lack of association, our study provides data on an area of research that is currently lacking in our setting.

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.

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium

Trichomonas vaginalis is a common protozoan parasite, which causes trichomoniasis associated with severe adverse reproductive outcomes. However, the underlying pathogenesis has not been fully understood. As the first line of defense against invading pathogens, the vaginal epithelial cells are highly responsive to environmental stimuli and contribute to the formation of the optimal luminal fluid microenvironment. The cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel widely distributed at the apical membrane of epithelial cells, plays a crucial role in mediating the secretion of Cl⁻ and HCO₃⁻. In this study, we investigated the effect of T. vaginalis on vaginal epithelial ion transport elicited by prostaglandin E₂ (PGE₂), a major prostaglandin in the semen. Luminal administration of PGE₂ triggered a remarkable and sustained increase of short-circuit current (I_SC) in rat vaginal epithelium, which was mainly due to Cl⁻ and HCO₃⁻ secretion mediated by the cAMP-activated CFTR. However, T. vaginalis infection significantly abrogated the I_SC response evoked by PGE₂, indicating impaired transepithelial anion transport via CFTR. Using a primary cell culture system of rat vaginal epithelium and a human vaginal epithelial cell line, we demonstrated that the expression of CFTR was significantly down-regulated after T. vaginalis infection. In addition, defective Cl⁻ transport function of CFTR was observed in T. vaginalis-infected cells by measuring intracellular Cl⁻ signals. Conclusively, T. vaginalis restrained exogenous PGE₂-induced anion secretion through down-regulation of CFTR in vaginal epithelium. These results provide novel insights into the intervention of reproductive complications associated with T. vaginalis infection such as infertility and disequilibrium in vaginal fluid microenvironment.

Trichomonas vaginalis is a common sexually transmitted parasite that colonized the urogenital mucosa and causes trichomoniasis, a neglected sexually transmitted infection associated with multiple adverse reproductive outcomes in humans. However, the underlying mechanisms remain largely unknown. The epithelial cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel conducting both Cl⁻ and HCO₃⁻, which participates in the regulation of luminal fluid microenvironment conducive to the success of reproductive events. Prostaglandin E₂ (PGE₂), a bioactive molecule abundant in human seminal fluid, has been demonstrated to exhibit a robust pro-secretory action by activating CFTR in the female genital tract epithelial cells such as endometrial epithelium. These discoveries motivated the authors to investigate the effect of T. vaginalis infection on exogenous PGE₂-induced transepithelial transport of electrolytes in vagina. Here, we found that in rat vaginal epithelium, luminal administration of PGE₂ elicited a response of Cl⁻ and HCO₃⁻ secretion mediated by cAMP-activated CFTR. However, T. vaginalis infection impaired transepithelial anion transport evoked by PGE₂, which is probably related to the defective expression and function of CFTR. These outcomes may complement and expand our knowledge of the complex interaction between T. vaginalis and the infected host, providing a novel therapeutic strategy for disequilibrium in vaginal fluid microenvironment and infertility induced by T. vaginalis infection.

The Estimated Lifetime Medical Cost of Chlamydia, Gonorrhea, and Trichomoniasis in the United States, 2018

BACKGROUND

The purpose of this study was to provide updated estimates of the average lifetime medical cost per infection for chlamydia, gonorrhea, and trichomoniasis.

METHODS

We adapted a published decision tree model that allowed for 7 possible outcomes of infection: (1) symptomatic infection, treated, no sequelae; (2) symptomatic infection, not treated, sequelae; (3) symptomatic infection, not treated, no sequelae; (4) asymptomatic infection, treated, sequelae; (5) asymptomatic infection, treated, no sequelae; (6) asymptomatic infection, not treated, sequelae; and (7) asymptomatic infection, not treated, no sequelae. The base case values and ranges we applied for the model inputs (i.e., the probability and cost assumptions) were based on published studies.

RESULTS

The estimated lifetime medical costs per infection for men and women, respectively, were $46 (95% credibility interval, $32-$62) and $262 ($127-$483) for chlamydia, $78 ($36-$145) and $254 ($96-$518) for gonorrhea, and $5 ($1-$14) and $36 ($17-$58) for trichomoniasis. Cost estimates for men were most sensitive to assumptions regarding the probability that the infection is symptomatic, the probability of treatment if asymptomatic, and the cost of treatment of infection. Cost estimates for chlamydia and gonorrhea in women were most sensitive to assumptions regarding the probability and cost of subsequent pelvic inflammatory disease.

CONCLUSIONS

These estimates of the lifetime medical cost per infection can inform updated estimates of the total annual cost of sexually transmitted infections in the United States, as well as analyses of the value and cost-effectiveness of sexually transmitted infection prevention interventions.

Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis

Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.

Adherence of Trichomonas vaginalis to SiHa Cells is Inhibited by Diphenyleneiodonium

Microbial adhesion is critical for parasitic infection and colonization of host cells. To study the host–parasite interaction in vitro, we established a flow cytometry-based assay to measure the adherence of Trichomonas vaginalis to epithelial cell line SiHa. SiHa cells and T. vaginalis were detected as clearly separated, quantifiable populations by flow cytometry. We found that T. vaginalis attached to SiHa cells as early as 30 min after infection and the binding remained stable up to several hours, allowing for analysis of drug treatment efficacy. Importantly, NADPH oxidase inhibitor DPI treatment induced the detachment of T. vaginalis from SiHa cells in a dose-dependent manner without affecting host cell viability. Thus, this study may provide an understanding for the potential development of therapies against T. vaginalis and other parasite infections.

Neutrophil interactions with the sexually transmitted parasite Trichomonas vaginalis: implications for immunity and pathogenesis

Trichomoniasis is the third most common sexually transmitted infection in humans and is caused by the protozoan parasite, Trichomonas vaginalis (Tv). Pathogenic outcomes are more common in women and generally include mild vaginitis or cervicitis. However, more serious effects associated with trichomoniasis include adverse reproductive outcomes. Like other infectious agents, pathogenesis from Tv infection is predicted to be the result of both parasite and host factors. At the site of infection, neutrophils are the most abundant immune cells present and probably play key roles in both parasite clearance and inflammatory pathology. Here, we discuss the evidence that neutrophils home to the site of Tv infection, kill the parasite, and that in some circumstances, parasites possibly evade neutrophil-directed killing. In vitro, the parasite is killed by neutrophils using a novel antimicrobial mechanism called trogocytosis, which probably involves both innate and adaptive immunity. While mechanisms of evasion are mostly conjecture at present, the persistence of Tv infections in patients argues strongly for their existence. Additionally, many strains of Tv harbour microbial symbionts Mycoplasma hominis or Trichomonasvirus, which are both predicted to impact neutrophil responses against the parasite. Novel research tools, especially animal models, will help to reveal the true outcomes of many factors involved in neutrophil-Tv interactions during trichomoniasis.

Development of a convenient detection method for Trichomonas vaginalis based on loop-mediated isothermal amplification targeting adhesion protein 65

Background

Trichomoniasis resulting from Trichomonas vaginalis (T. vaginalis) has been considered as a commonly seen disease with the transmission way of sex. At present, the detection methods of T. vaginalis mainly include wet mount microscopy, culture, PCR, immunofluorescence and ELISA. However, all of these detection methods exist shortcomings.

Methods

In this study, a loop-mediated isothermal amplification (LAMP) assay that targeted the species-specific sequence of adhesion protein 65 (AP65) gene had been conducted to detect T. vaginalis. The optimum reaction system and conditions were optimized in this rapid detection method.

Results

The results of sensitivity analysis showed that the LAMP assay targeting the AP65 gene was 1000 times more sensitive than the nested PCR targeting the actin gene commonly used for detection of T. vaginalis, and the detecting limitation of the former was 10 trichomonad. Moreover, the amplification of the target gene AP65 by LAMP assay exhibited high specificity and the product was exclusively from T. vaginalis. The detection technique of LAMP did not exhibit cross-reactivity with the common pathogens of Trichinella spiralis, Toxoplasma gondii, Escherichia coli, Candida albicans, Staphylococcus aureus, Haemophilus.

Conclusions

According to the present study, the LAMP assay with the target of AP65 gene, was suitable for the early diagnosis of T. vaginalis infections. Consequently, the LAMP assay was proposed by the current study as a point-of-care examination and an alternative molecular tool which exhibited the potential value in the treatment, control and prevention of trichomoniasis transmission and relevant complication.

Updates in trichomonas treatment including persistent infection and 5-nitroimidazole hypersensitivity

PURPOSE OF REVIEW

The purpose of this review is to update information on treatment of Trichomonas vaginalis. T. vaginalis is estimated to be the most common treatable sexually transmitted infection. In the world and is associated with poor birth outcomes, cervical cancer, sperm motility and morphology issues, and HIV acquisition and transmission.

RECENT FINDINGS

The efficacy of the recommended 2-g oral single-dose metronidazole (MTZ) for the treatment of T. vaginalis in women has recently been challenged. Two recent multicentered randomized trials and a meta-analysis have demonstrated that the 7-day dose of MTZ 500 mg twice daily was nearly two times more efficacious at clearing infection compared with the 2-g dose. Partner treatment is also essential, since up to 70% of male sexual partners can be infected and rescreening of treated women at 3 months is also recommended given the high repeat infection rates. Future studies should examine the importance of treating asymptomatic T. vaginalis, best treatment for men, the influence of the microbiome on treatment efficacy and different formulations of intravaginal treatments for hypersensitivity.

SUMMARY

7-day 500 mg twice daily MTZ should be used as the first line treatment for T. vaginalis-infected women.

School suspension predicts trichomoniasis five years later in a matched sample

BACKGROUND

Young adults who were suspended from school during adolescence are more likely than matched non-suspended youth to be arrested, on probation, or not graduate from high school, which are STI risk factors. This study evaluates whether suspension is a marker for STI risk among young adults who avoid subsequent negative effects.

METHODS

This study evaluated whether suspension predicts a positive test for chlamydia, gonorrhea, or trichomoniasis in a urine sample using matched sampling in the National Longitudinal Study of Adolescent and Adult Health (Add Health), and evaluated potential mediators between suspension and STI status using causal mediation analysis. We used Mahalanobis and exact matched sampling within propensity score calipers to compare 381 youth suspended for the first time in a 1-year period with 980 non-suspended youth. The suspended and non-suspended youth were similar on 67 pre-suspension variables. We evaluated STI outcomes 5 years after suspension.

RESULTS

Before matching, suspended youth were more likely to test positive for trichomoniasis and gonorrhea, but not chlamydia, than non-suspended youth. Suspended youth were more likely to test positive for trichomoniasis 5 years after suspension than matched non-suspended youth (OR = 2.87 (1.40, 5.99)). Below-median household income before suspension explained 9% of the suspension-trichomoniasis association (p = 0.02), but criminal justice involvement and educational attainment were not statistically significantly mediators.

CONCLUSIONS

School suspension is a marker for STI risk. Punishing adolescents for initial deviance may cause them to associate with riskier sexual networks even if they graduate high school and avoid criminal justice system involvement. Suspension may compound disadvantages for youth from below-median-income families, who have fewer resources for recovering from setbacks.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.