Current issues and considerations regarding trichomoniasis and human immunodeficiency virus in African-Americans

Distinct features of the host-parasite interactions between nonadherent and adherent Trichomonas vaginalis isolates

Cytoadherence of Trichomonas vaginalis to human vaginal epithelial cells (hVECs) was previously shown to involve surface lipoglycans and several reputed adhesins on the parasite. Herein, we report some new observations on the host-parasite interactions of adherent versus nonadherent T. vaginalis isolates to hVECs. The binding of the TH17 adherent isolate to hVECs exhibited an initial discrete phase followed by an aggregation phase inhibited by lactose. T. vaginalis infection immediately induced surface expression of galectin-1 and -3, with extracellular amounts in the spent medium initially decreasing and then increasing thereafter over the next 60 min. Extracellular galectin-1 and -3 were detected on the parasite surface but only the TH17 adherent isolate could uptake galectin-3 via the lysosomes. Only the adherent isolate could morphologically transform from the round-up flagellate with numerous transient protrusions into a flat amoeboid form on contact with the solid surface. Cytochalasin D challenge revealed that actin organization was essential to parasite morphogenesis and cytoadherence. Real-time microscopy showed that parasite exploring and anchoring on hVECs via the axostyle may be required for initial cytoadherence. Together, the parasite cytoskeleton behaviors may collaborate with cell surface adhesion molecules for cytoadherence. The nonadherent isolate migrated faster than the adherent isolate, with motility transiently increasing in the presence of hVECs. Meanwhile, differential histone acetylation was detected between the two isolates. Also, TH17 without Mycoplasma symbiosis suggests that symbiont might not determine TH17 innate cytoadherence. Our findings regarding distinctive host-parasite interactions of the isolates may provide novel insights into T. vaginalis infection.

Trichomoniasis, a new look at a common but neglected STI in African descendance population in the United States and the Black Diaspora. A review of its incidence, research prioritization, and the resulting health disparities

Structural racism plays a significant role in limited access to higher education, financial resources, employment opportunities, and high-quality healthcare for African Americans. The lack of healthcare equity and infrastructure has directly contributed to overall poor healthcare outcomes for the Black community. Studies have shown that adverse health outcomes such as sexually transmitted diseases (STDs) are more prevalent in African Americans, regardless of their socioeconomic factors and lifestyles. For example, trichomoniasis, transmitted sexually by its etiological agent, Trichomonas vaginalis (T. vaginalis), predisposes those infected to co-infections with other STDs, such as human immunodeficiency virus (HIV), herpes, and other related infections. Our review showcases the impact of trichomoniasis on the health of the Black community with an emphasis on African American women. A critical examination of the socio-demographic history of Black people in the United States (US) is vital to illustrate the origin of past and current racial health disparities. Further, we expand the complex and nuanced conversation on the intersectionality of racism, health equity, and innovative epidemiological and biomedical research strategies needed to eradicate this global public health threat.

A Novel Trichomonas vaginalis Surface Protein Modulates Parasite Attachment via Protein:Host Cell Proteoglycan Interaction

Trichomonas vaginalis is a highly prevalent, sexually transmitted parasite which adheres to mucosal epithelial cells to colonize the human urogenital tract. Despite adherence being crucial for this extracellular parasite to thrive within the host, relatively little is known about the mechanisms or key molecules involved in this process. Here, we have identified and characterized a T. vaginalis hypothetical protein, TVAG_157210 (TvAD1), as a surface protein that plays an integral role in parasite adherence to the host. Quantitative proteomics revealed TvAD1 to be ∼4-fold more abundant in parasites selected for increased adherence (MA parasites) than the isogenic parental (P) parasite line. De novo modeling suggested that TvAD1 binds N-acetylglucosamine (GlcNAc), a sugar comprising host glycosaminoglycans (GAGs). Adherence assays utilizing GAG-deficient cell lines determined that host GAGs, primarily heparan sulfate (HS), mediate adherence of MA parasites to host cells. TvAD1 knockout (KO) parasites, generated using CRISPR-Cas9, were found to be significantly reduced in host cell adherence, a phenotype that is rescued by overexpression of TvAD1 in KO parasites. In contrast, there was no significant difference in parasite adherence to GAG-deficient lines by KO parasites compared with wild-type, which is contrary to that observed for KO parasites overexpressing TvAD1. Isothermal titration calorimetric (ITC) analysis showed that TvAD1 binds to HS, indicating that TvAD1 mediates host cell adherence via HS interaction. In addition to characterizing the role of TvAD1 in parasite adherence, these studies reveal a role for host GAG molecules in T. vaginalis adherence.IMPORTANCE The ability of the sexually transmitted parasite Trichomonas vaginalis to adhere to its human host is critical for establishing and maintaining an infection. Yet how parasites adhere to host cells is poorly understood. In this study, we employed a novel adherence selection method to identify proteins involved in parasite adherence to the host. This method led to the identification of a protein, with no previously known function, that is more abundant in parasites with increased capacity to bind host cells. Bioinformatic modeling and biochemical analyses revealed that this protein binds a common component on the host cell surface proteoglycans. Subsequent creation of parasites that lack this protein directly demonstrated that the protein mediates parasite adherence via an interaction with host cell proteoglycans. These findings both demonstrate a role for this protein in T. vaginalis adherence to the host and shed light on host cell molecules that participate in parasite colonization.

Prevalence and Correlates of Trichomonas vaginalis Infection Using the OSOM Rapid Point-of-Care Test Among Women Attending New York City Sexual Health Clinics, May-July 2016

Using electronic medical record data and OSOM Trichomonas Rapid Tests, Trichomonas vaginalis prevalence was 9.3% among women attending New York City sexual health clinics in 2016. Positivity was associated with black race (adjusted odds ratios 3.73; 95% confidence interval, 1.9-7.1) and vaginal pH of 4.5 or greater (adjusted odds ratios, 1.9; 95% CI, 1.2-3.3).

The prevalence and risk factors for Trichomonas vaginalis infection amongst human immunodeficiency virus-infected pregnant women attending the antenatal clinics of a university teaching hospital in Lagos, South-Western, Nigeria

Background

Trichomonas vaginalis infection is the most prevalent non-viral sexually transmitted infection worldwide. Interactions between this infection and human immunodeficiency virus (HIV) may cause adverse pregnancy outcomes such as preterm labour, premature rupture of membranes, chorioamnionitis, low birth weight and post-abortal sepsis.

Aims

This study was aimed to determine the prevalence and risk factors of T. vaginalis infection amongst HIV-positive pregnant women attending antenatal care at the Lagos University Teaching Hospital (LUTH), Lagos, Nigeria.

Subjects and Methods

This was an analytical cross-sectional study in which 320 eligible participants which included 160 HIV-positive (case group) and 160 HIV-negative (control group) pregnant women were recruited at the antenatal clinic of LUTH. A structured pro forma was used to collect data from consenting participants after which high vaginal swabs were collected, processed and examined for T. vaginalis. The association between categorical variables was tested using the Chi-square test and Fisher's exact test where applicable. All significances were reported at P < 0.05.

Results

The prevalence of T. vaginalis infection amongst HIV-positive and HIV-negative pregnant women were 10% and 8.1%, respectively (P = 0.559). Significant risk factors for T. vaginalis infection in the HIV-positive pregnant women were early coitarche (P < 0.005) and multiple lifetime sexual partners (P = 0.021). There was no relationship between the T. vaginalis infection and the immunological markers of HIV infection.

Conclusions

While this study does not provide grounds for universal screening of pregnant women for T. vaginalis infection as a tool of reducing HIV acquisition, especially in pregnancy, campaign to create better sexual health awareness should be commenced as a way to contributing to the reduction in T. vaginalis infection during pregnancy and perinatal transmission of HIV.

A Novel Cadherin-like Protein Mediates Adherence to and Killing of Host Cells by the Parasite Trichomonas vaginalis

Trichomonas vaginalis, a prevalent sexually transmitted parasite, adheres to and induces cytolysis of human mucosal epithelial cells. We have characterized a hypothetical protein, TVAG_393390, with predicted tertiary structure similar to that of mammalian cadherin proteins involved in cell-cell adherence. TVAG_393390, renamed cadherin-like protein (CLP), contains a calcium-binding site at a position conserved in cadherins. CLP is surface localized, and its mRNA and protein levels are significantly upregulated upon parasite adherence to host cells. To test the roles of CLP and its calcium-binding dependency during host cell adherence, we first demonstrated that wild-type CLP (CLP) binds calcium with a high affinity, whereas the calcium-binding site mutant protein (CLP-mut) does not. CLP and CLP-mut constructs were then used to overexpress these proteins in T. vaginalis Parasites overexpressing CLP have ∼3.5-fold greater adherence to host cells than wild-type parasites, and this increased adherence is ablated by mutating the calcium-binding site. Additionally, competition with recombinant CLP decreased parasite binding to host cells. We also found that overexpression of CLP induced parasite aggregation which was further enhanced in the presence of calcium, whereas CLP-mut overexpression did not affect aggregation. Lastly, parasites overexpressing wild-type CLP induced killing of host cells ∼2.35-fold, whereas parasites overexpressing CLP-mut did not have this effect. These analyses describe the first parasitic CLP and demonstrate a role for this protein in mediating parasite-parasite and host-parasite interactions. T. vaginalis CLP may represent convergent evolution of a parasite protein that is functionally similar to the mammalian cell adhesion protein cadherin, which contributes to parasite pathogenesis.IMPORTANCE The adherence of pathogens to host cells is critical for colonization of the host and establishing infection. Here we identify a protein with no known function that is more abundant on the surface of parasites that are better at binding host cells. To interrogate a predicted function of this protein, we utilized bioinformatic protein prediction programs which allowed us to uncover the first cadherin-like protein (CLP) found in a parasite. Cadherin proteins are conserved metazoan proteins with central roles in cell-cell adhesion, development, and tissue structure maintenance. Functional characterization of this CLP from the unicellular parasite Trichomonas vaginalis demonstrated that the protein mediates both parasite-parasite and parasite-host adherence, which leads to an enhanced killing of host cells by T. vaginalis Our findings demonstrate the presence of CLPs in unicellular pathogens and identify a new host cell binding protein family in a human-infective parasite.

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.

Immunocytochemistry Improving the Diagnosis of Trichomonas vaginalis Infections

The aim of this study was to evaluate the immunocytochemistry (ICC) to diagnose trichomoniasis, particularly asymptomatic infections. By culture serial dilutions, ICC was able to detect 1 trophozoite/mL, while the culture was positive up to 100 trophozoites/mL. The ICC in vivo detection capability was assessed in vaginal secretions of mice experimentally infected and in vaginal swabs from asymptomatic HIV-positive pregnant women compared with culture. All vaginal secretion samples from mice were positive according to both methods. Swabs from fifty-five asymptomatic women were positive in four (7.27%) of them by culture. Beyond these four, another ten (25.45%) women were positive by immunocytochemistry, proving their higher sensitivity (p = 0.002), noticing 3.5 times more positives. ICC had better performance in both successive dilutions as in asymptomatic women, showing higher sensitivity and specificity. In this way, its facility of execution and cost-effectiveness support its practicality, as a routine procedure to diagnose trichomoniasis not only when the parasite load is lower but probably in all clinical scenarios.

Investigation of the presence of Trichomonas vaginalis in infertile Turkish women

Background

Trichomoniasis is a sexually transmitted vaginal infection caused by a protozoan called Trichomonas vaginalis. Its prevalence ranges between 3–40% among randomly tested women.

Objectives

To investigate the presence of T. vaginalis in infertile women presenting to a Turkish gynecology outpatient clinic using parasitological methods.

Methods

The study population comprised 51 patient participants who attended the gynecology clinic of Mustafa Kemal University Hospital between March and August 2013. The women were divided into those presenting with infertility (n = 22) and a patient control group (n = 29). Women in the control group had complaints other than infertility. Microscopic examination, Giemsa staining, and cysteine-peptone-liver-maltose culture were performed on samples taken from posterior fornix tested for T. vaginalis.

Results

T. vaginalis was observed in 18% (n = 4) of infertile patients and in none of the control group (P = 0.03).

Conclusions

Asymptomatic infertile women should be examined for T. vaginalis infection, which may play a role as a cause or contributing factor in infertility.

Genotyping, Drug Susceptibility and Prevalence Survey of Trichomonas vaginalis among Women Attending Gynecology Clinics in Hamadan, Western Iran, in 2014-2015

BACKGROUND

In spite of sufficient knowledge about phenotypic variation of Trichomonas vaginalis, its genetic characteristics are poorly understood. We carried out a molecular epidemiology study in which in vitro metronidazole susceptibility of T. vaginalis isolates was considered.

METHODS

This study was conducted on 862 women admitted to Gynecology Clinics in Hamadan, west of Iran, during 2014-2015. After recording the socio-demographic and clinical characteristics of participants, vaginal swab samples were taken and subjected to microscopic examination, culture, in vitro sensitivity testing and PCR-restriction fragment length polymorphism (RFLP) analysis.

RESULTS

T. vaginalis was detected in 1.9% (16/862) of the samples using two parasitological methods. The all T. vaginalis isolates that subjected to drug susceptibility analysis were sensitive to metronidazole with MICs ranged from 0.4 to 12.8 μg/ml. T. vaginalis genotyping by using actin gene and PCR-RFLP analysis identified three actin type; A (9, 56%), I (6, 38%) and E (1, 6%). No significant correlation was observed between actin genotypes and their clinical manifestation (P>0.05).

CONCLUSION

The prevalence of T. vaginalis infection is not noticeable in the region and the most of isolates are hypersensitive to metronidazole. Further studies are needed to clarify the efficiency of the actin gene, as a reliable genetic marker, for molecular epidemiology of trichomoniasis.

Recent Insights into the HIV/AIDS Pandemic

Etiology, transmission and protection: Transmission of HIV, the causative agent of AIDS, occurs predominantly through bodily fluids. Factors that significantly alter the risk of HIV transmission include male circumcision, condom use, high viral load, and the presence of other sexually transmitted diseases. Pathology/Symptomatology: HIV infects preferentially CD4+ T lymphocytes, and Monocytes. Because of their central role in regulating the immune response, depletion of CD4+ T cells renders the infected individual incapable of adequately responding to microorganisms otherwise inconsequential. Epidemiology, incidence and prevalence: New HIV infections affect predominantly young heterosexual women and homosexual men. While the mortality rates of AIDS related causes have decreased globally in recent years due to the use of highly active antiretroviral therapy (HAART) treatment, a vaccine remains an elusive goal. Treatment and curability: For those afflicted HIV infection remains a serious illness. Nonetheless, the use of advanced therapeutics have transformed a dire scenario into a chronic condition with near average life spans. When to apply those remedies appears to be as important as the remedies themselves. The high rate of HIV replication and the ability to generate variants are central to the viral survival strategy and major barriers to be overcome. Molecular mechanisms of infection: In this review, we assemble new details on the molecular events from the attachment of the virus, to the assembly and release of the viral progeny. Yet, much remains to be learned as understanding of the molecular mechanisms used in viral replication and the measures engaged in the evasion of immune surveillance will be important to develop effective interventions to address the global HIV pandemic.

Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis

Trichomonas vaginalis (Tv) is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells.

Trichomonas vaginalis: An Updated Overview Towards Diagnostic Improvement

The protozoan Trichomonas vaginalis (TV) is responsible for trichomonosis, a sexually transmitted disease (STD) with a significant incidence worldwide. This infection is one of the most common non-viral STDs, representing almost 50% of all curable STDs. Trichomonosis has an incidence of 180 million new cases worldwide. Nowadays, the 'gold standard' for TV diagnosis remains the use of in vitro cultures combined with daily visual microscopic evaluations, which is a time-consuming and low sensitive method. Recent diagnostic methodologies include imunocromatographic assays and molecular biology techniques. The use of the latter has improved enormously the sensitivity and specificity of TV diagnosis, despite, however, none being unable to identify the presence of live parasites. By understanding the biology, the pathogenesis, the proteomic profile and its relation with the parasite's virulence mechanisms, new possibilities towards diagnostic techniques can arise. This review covers various important aspects of vaginal trichomonosis from the parasite's biology and virulence to recent improvements in diagnostic techniques and also metabolic and protein discoveries.

A Trichomonas vaginalis Rhomboid Protease and Its Substrate Modulate Parasite Attachment and Cytolysis of Host Cells

Trichomonas vaginalis is an extracellular eukaryotic parasite that causes the most common, non-viral sexually transmitted infection worldwide. Although disease burden is high, molecular mechanisms underlying T. vaginalis pathogenesis are poorly understood. Here, we identify a family of putative T. vaginalis rhomboid proteases and demonstrate catalytic activity for two, TvROM1 and TvROM3, using a heterologous cell cleavage assay. The two T. vaginalis intramembrane serine proteases display different subcellular localization and substrate specificities. TvROM1 is a cell surface membrane protein and cleaves atypical model rhomboid protease substrates, whereas TvROM3 appears to localize to the Golgi apparatus and recognizes a typical model substrate. To identify TvROM substrates, we interrogated the T. vaginalis surface proteome using both quantitative proteomic and bioinformatic approaches. Of the nine candidates identified, TVAG_166850 and TVAG_280090 were shown to be cleaved by TvROM1. Comparison of amino acid residues surrounding the predicted cleavage sites of TvROM1 substrates revealed a preference for small amino acids in the predicted transmembrane domain. Over-expression of TvROM1 increased attachment to and cytolysis of host ectocervical cells. Similarly, mutations that block the cleavage of a TvROM1 substrate lead to its accumulation on the cell surface and increased parasite adherence to host cells. Together, these data indicate a role for TvROM1 and its substrate(s) in modulating attachment to and lysis of host cells, which are key processes in T. vaginalis pathogenesis.

Trichomonas vaginalis, a common pathogen with a worldwide distribution, causes a sexually transmitted infection and exacerbates other diseases. Estimated to infect over a million people annually in the United States alone, the Center for Disease Control and Prevention categorized trichomoniasis as one of five neglected parasitic diseases in the US in 2014. Only one class of drug is available to treat T. vaginalis infection, making discovery of parasite factors contributing to host colonization critical for the development of new therapeutics. Here we report the first characterization of T. vaginalis intramembrane rhomboid proteases. One protease, TvROM1, is shown to increase the parasite’s association with and destruction of host cells. We further identified two TvROM1 substrates, one of which we demonstrate is involved in modulating host: parasite interactions. This study highlights the involvement of rhomboid proteases in T. vaginalis pathogenic processes, and provides further support for targeting parasite surface proteases for therapeutic intervention.

Modulation of dendritic cell function by Trichomonas vaginalis-derived secretory products

Trichomoniasis caused by the parasitic protozoan Trichomonas vaginalis is the most common sexually transmitted disease in the world. Dendritic cells are antigen presenting cells that initiate immune responses by directing the activation and differentiation of naïve T cells. In this study, we analyzed the effect of Trichomonas vaginalis-derived Secretory Products on the differentiation and function of dendritic cells. Differentiation of bone marrow-derived dendritic cells in the presence of T. vaginalis-derived Secretory Products resulted in inhibition of lipopolysaccharide-induced maturation of dendritic cells, down-regulation of IL-12, and up-regulation of IL-10. The protein components of T. vaginalis-derived Secretory Products were shown to be responsible for altered function of bone marrow-derived dendritic cells. Chromatin immunoprecipitation assay demonstrated that IL-12 expression was regulated at the chromatin level in T. vaginalis-derived Secretory Productstreated dendritic cells. Our results demonstrated that T. vaginalis-derived Secretory Products modulate the maturation and cytokine production of dendritic cells leading to immune tolerance. [BMB Reports 2015; 48(2): 103-108]

Trichomonas vaginalis: pathogenicity and potential role in human reproductive failure

PURPOSE

Trichomonas vaginalis, which colonizes the genitourinary tract of men and women, is a sexually transmitted parasite causing symptomatic or asymptomatic trichomoniasis. The host-parasite relationship is very complex, and clinical symptoms cannot likely be attributed to a single pathogenic effect. Among the many factors responsible for interactions between T. vaginalis and host tissues, contact-dependent and contact-independent mechanisms are important in pathogenicity, as is the immune response.

METHODS

This review focuses on the potential virulence properties of T. vaginalis and its role in female and male infertility.

RESULTS

It highlights the association between T. vaginalis infection and serious adverse health consequences experienced by women, including infertility, preterm birth and low-birth-weight infants. Long-term clinical observations and results of in vitro experimental studies indicate that in men, trichomoniasis has been also associated with infertility through inflammatory damage to the genitourinary tract or interference with sperm function.

CONCLUSION

These results contribute significantly to improving our knowledge of the role of parasitic virulence factors in the development of infection and its role in human infertility.

Trichomonas vaginalis infection among homeless and unstably housed adult women living in a resource-rich urban environment

OBJECTIVE

The social context of poverty is consistently linked to Trichomonas vaginalis infection, yet few studies regarding T. vaginalis have been conducted exclusively among low-income individuals. We identified social determinants of health associated with prevalent T. vaginalis infection among homeless and unstably housed adult women.

METHODS

Between April and October of 2010, we conducted cross-sectional T. vaginalis screening and behavioural interviews in an existing cohort of San Francisco homeless and unstably housed women. Data were analysed using multivariable logistical regression.

RESULTS

Among 245 study participants, the median age was 47 years and 72% were of non-Caucasian race/ethnicity. T. vaginalis prevalence was 12%, compared to 3% in the general population, and 33% of infected individuals reported no gynaecological symptoms. In adjusted analysis, the odds of T. vaginalis infection were lower among persons older than 47 years, the population median (OR=0.14, 95% CI 0.04 to 0.38), and higher among those reporting recent short-term homeless shelter stays (OR=5.36, 95% CI 1.57 to 18.26). Race and income did not reach levels of significance. Sensitivity analyses indicated that testing all women who report recent unprotected sex would identify more infections than testing those who report gynaecological symptoms (20/30 vs 10/30; p=0.01).

CONCLUSIONS

The prevalence of T. vaginalis is high among homeless and unstably housed adult women, over one-third of infected individuals have no gynaecological symptoms, and correlates of infection differ from those reported in the general population. Targeted screening and treatment among impoverished women reporting recent unprotected sex, particularly young impoverished women and all women experiencing short-term homelessness, may reduce complications related to this treatable infection.

Trichomonas vaginalis: a review of epidemiologic, clinical and treatment issues

Trichomonas vaginalis (TV) is likely the most common non-viral sexually transmitted infection (STI) in the world. It is as an important source of reproductive morbidity, a facilitator of HIV transmission and acquisition, and thus it is an important public health problem. Despite its importance in human reproductive health and HIV transmission, it is not a reportable disease and surveillance is not generally done. This is problematic since most persons infected with TV are asymptomatic. Metronidazole (MTZ) has been the treatment of choice for women for decades, and single dose has been considered the first line of therapy. However, high rates of retest positive are found among TV infected persons after single dose MTZ treatment. This has not been explained by drug resistance since in vitro resistance is only 2-5 %. Treatment failure can range from 7-10 % and even higher among HIV+ women. Treatment efficacy may be influenced by vaginal ecology. The origins of repeat positives need further explanation and better treatment options are needed.

The incidence of Trichomonas vaginalis infection in women attending nine sexually transmitted diseases clinics in the USA

OBJECTIVES

Trichomoniasis (TV) is associated with an increased risk of acquisition of sexually transmitted diseases (STDs) and HIV. The purpose of this study is to evaluate factors associated with incidence TV among female STD clinic attendees in the USA.

METHODS

Data were collected from women participating in a randomised controlled trial evaluating brief risk reduction counselling at the time of HIV testing to reduce sexually transmitted infections (STIs) incidence in STD clinics. Participants recruited from STD clinics underwent STI testing at baseline and 6-month follow-up. TV testing was performed using Nucleic Acid Amplification Test.

RESULTS

1704 participants completed study assessments. Prevalence of TV was 14.6%, chlamydia 8.6%, gonorrhoea 3.0%, herpes simplex virus 2 44.7% and HIV 0.4%. Cumulative 6-month incidence of TV was 7.5%. Almost 50% of the incident TV cases had TV at baseline and had received treatment. Factors associated with incidence of TV were having chlamydia, TV and HIV at baseline: TV relative risk (RR)=3.37 (95% CI 2.35 to 4.83, p<0.001); chlamydia RR=1.92 (95% CI 1.23 to 2.99, p=0.04); and HIV=1.59 (95% CI 1.01 to 2.50, p=0.047).

CONCLUSIONS

Prevalent and incident TV is common among STD clinic attendees; and baseline TV is the main risk factor for incident TV, suggesting high rates of reinfection or treatment failures. This supports the importance of rescreening women after treatment for TV, evaluating current treatment regimens and programmes to ensure treatment of sexual partners.

CLINICAL TRIAL NUMBER

NCT01154296.

Epidemiology and treatment of trichomoniasis

Trichomonas vaginalis is the most common nonviral sexually transmitted infection (STI) in the world. It was once thought to be a nuisance STI, but it is now being recognized as an important source of reproductive morbidity and a facilitator of HIV transmission and acquisition, and thus it is an important public health problem. The prevalence of T. vaginalis varies greatly by geography and risk group, but is more common among persons of African descent and appears to increase with age, though this may be a screening phenomenon. Wet mount and culture are simple diagnostics, but have lower sensitivity than nucleic acid amplification techniques presently approved for women only. Single dose (2 g) metronidazole (MTZ) for both the index patient and their sexual partners is the preferred treatment. High rates of retest positivity are found after single-dose treatment which are likely due to clinical resistance rather than re-infection and/or drug resistance.

Evaluation of Different Staining Techniques in the Diagnosis of Trichomonas vaginalis Infection in Females of Reproductive Age Group

BACKGROUND

Trichomonas vaginalis is a parasitic protozoan which causes most common non viral sexually transmitted disease trichomoniasis. Direct microscopic examination of vaginal fluid remains the most widely used diagnostic test. Although, wet mount examination is the most cost-effective diagnostic test, but it has low sensitivity resulting in under diagnosis of the disease. Therefore, to overcome this problem, various staining techniques like giemsa and acridine orange can be used along with wet mount examination for diagnosis of T. vaginalis infection.

OBJECTIVE

The present study was done to evaluate the efficacy of Giemsa and Acridine Orange staining in comparison with wet mount examination for the diagnosis of vaginal trichomoniasis.

MATERIALS AND METHODS

A total of 615 female patients of reproductive age group having vaginal discharge were included in the study and swabs containing vaginal fluids were taken to perform wet mount examination, giemsa staining and acridine orange staining.

RESULT

Trichomonas vaginalis infection was detected in 37 patients with maximum cases (6.0%) detected by acridine orange staining, followed by giemsa staining (4.9%), whereas, wet mount examination was able to detect only 4.1% cases. Wet mount examination gave a sensitivity of 67.6%, whereas, the sensitivity of giemsa staining and acridine orange staining was found to be 80% and 100% respectively.

CONCLUSION

Since the performance of both the staining techniques was found to be much better in comparison to wet mount examination, and they also detected several wet mount negative cases, they should be used as an adjunct to wet mount examination. This will also be beneficial to the overall health of the patient by early diagnosis and treatment of cases, thereby, reducing the development of associated morbidity.

Correlates of incident Trichomonas vaginalis infections among African American female adolescents

BACKGROUND

Trichomonas vaginalis is the most common curable sexually transmitted infection associated with adverse reproductive health and pregnancy outcomes and may amplify HIV transmission. The objective was to identify correlates of incident T. vaginalis infections among African American adolescent girls.

METHODS

Data were collected via audio computer-assisted self-interviews at baseline and every 6 months for 18 months from 701 African American girls (14-20 years) in an HIV prevention trial. At each assessment, self-collected vaginal swabs were assayed for T. vaginalis, Chlamydia trachomatis, and Neisseria gonorrhoeae. Generalized estimating equations assessed associations between incident T. vaginalis infection and sociodemographic characteristics, substance use, partner-level factors, sexual risk behaviors, douching, and other sexually transmitted infections.

RESULTS

Of 605 (86.3%) participants who completed at least 1 follow-up assessment, an incident T. vaginalis infection was detected among 20.0% (n = 121). Factors associated with incident infection in adjusted analysis included the following: cigarette smoking (adjusted odds ratio [AOR], 1.66; 95% confidence interval [CI], 1.04-2.64), using alcohol on an increasing number of days in the past 3 months (AOR, 1.02; 95% CI, 1.00-1.04), acquisition of C. trachomatis (AOR, 2.27; 95% CI, 1.40-3.69) or N. gonorrhoeae (AOR, 5.71; 95% CI, 2.97-11.02), and T. vaginalis infection at the previous assessment (AOR, 3.16; 95% CI, 1.96-5.07).

CONCLUSIONS

Incident T. vaginalis infections were common. Strategies to reduce infection rates among this population may include improving partner notification and treatment services. The benefits of rescreening, screening adolescents screened for or infected with C. trachomatis or N. gonorrhoeae, and associations between substance use and T. vaginalis acquisition warrant further investigation.

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, while infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with other disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harboring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit.

Co-occurrence of Trichomonas vaginalis and bacterial vaginosis and vaginal shedding of HIV-1 RNA

BACKGROUND

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are independently associated with increased risk of vaginal shedding in HIV-positive women. Because these 2 conditions commonly co-occur, this study was undertaken to examine the association between TV/BV co-occurrence and vaginal shedding of HIV-1 RNA.

METHODS

HIV-positive women attending outpatient HIV clinics in 3 urban US cities underwent a clinical examination; were screened for TV, BV, Neisseria gonorrhoeae, Chlamydia trachomatis, and vulvovaginal candidiasis; and completed a behavioral survey. Women shedding HIV-1 RNA vaginally (≥50 copies/mL) were compared with women who had an undetectable (<50 copies/mL) vaginal viral load to determine if women who were TV positive and BV positive or had co-occurrence of TV/BV had higher odds of shedding vaginally when compared with women who did not have these conditions.

RESULTS

In this sample of 373 HIV-positive women, 43.1% (n = 161) had co-occurrence of TV/BV and 33.2% (n = 124) were shedding HIV-1 RNA vaginally. The odds of shedding HIV vaginally in the presence of TV alone or BV alone and when TV/BV co-occurred were 4.07 (95% confidence interval [CI], 1.78-9.37), 5.65 (95% CI, 2.64-12.01), and 18.63 (95% CI, 6.71-51.72), respectively, when compared with women with no diagnosis of TV or BV, and after adjusting for age, antiretroviral therapy status, and plasma viral load.

CONCLUSIONS

T. vaginalis and BV were independently and synergistically related to vaginal shedding of HIV-1 RNA. Screening and prompt treatment of these 2 conditions among HIV-positive women are important not only clinically but for HIV prevention, as well.

Signal transduction triggered by iron to induce the nuclear importation of a Myb3 transcription factor in the parasitic protozoan Trichomonas vaginalis

Iron was previously shown to induce rapid nuclear translocation of a Myb3 transcription factor in the protozoan parasite, Trichomonas vaginalis. In the present study, iron was found to induce a transient increase in cellular cAMP, followed by the nuclear influx of Myb3, whereas the latter was also induced by 8-bromo-cyclic AMP. Iron-inducible cAMP production and nuclear influx of Myb3 were inhibited by suramin and SQ22536, respective inhibitors of the Gα subunit of heterotrimeric G proteins and adenylyl cyclases. In contrast, the nuclear influx of Myb3 induced by iron or 8-bromo-cAMP was delayed or inhibited, respectively, by H89, the inhibitor of protein kinase A. Using liquid chromatography-coupled tandem mass spectrometry, Thr(156) and Lys(143) in Myb3 were found to be phosphorylated and ubiquitinated, respectively. These modifications were induced by iron and inhibited by H89, as shown by immunoprecipitation-coupled Western blotting. Iron-inducible ubiquitination and nuclear influx were aborted in T156A and K143R, but T156D was constitutively ubiquitinated and persistently localized to the nucleus. Myb3 was phosphorylated in vitro by the catalytic subunit of a T. vaginalis protein kinase A, TvPKAc. A transient interaction between TvPKAc and Myb3 and the phosphorylation of both proteins were induced in the parasite shortly after iron or 8-bromo-cAMP treatment. Together, these observations suggest that iron may induce production of cAMP and activation of TvPKAc, which then induces the phosphorylation of Myb3 and subsequent ubiquitination for accelerated nuclear influx. It is conceivable that iron probably exerts a much broader impact on the physiology of the parasite than previously thought to encounter environmental changes.

Regulation of nuclear translocation of the Myb1 transcription factor by TvCyclophilin 1 in the protozoan parasite Trichomonas vaginalis

In Trichomonas vaginalis, a Myb1 protein was previously demonstrated to repress transcription of an iron-inducible ap65-1 gene. In this study, a human cyclophilin A homologue, TvCyclophilin 1 (TvCyP1), was identified as a Myb1-binding protein using a bacterial two-hybrid library screening system. The recombinant TvCyP1 exhibited typical peptidyl-prolyl isomerase activity with kcat/Km of ∼7.1 μm(-1) s(-1). In a pulldown assay, the His-tagged Myb1 interacted with a GST-TvCyP1 fusion protein, which had an enzymatic proficiency half that of recombinant TvCyP1. Both the enzymatic proficiency of GST-TvCyP1 and its binding to His-Myb1 were eliminated by mutation of Arg(63) in the catalytic motif or inhibited by cyclosporin A. TvCyP1 was primarily localized to the hydrogenosomes by immunofluorescence assay, but it was also co-purified with Myb1 in certain vesicle fractions from differential and gradient centrifugations. Transgenic cells overexpressing HA-TvCyP1 had a higher level of nuclear Myb1 but a much lower level of Myb1 associated with the vesicles than control and those overexpressing HA-TvCyP1(R63A). Myb1 was detected at a much higher level in the HA-TvCyP1 protein complex than in the HA-TvCyP1(R63A) protein complex immunoprecipitated from P15 and P100, but not S100, fractions of postnuclear lysates. A TvCyP1-binding motif, (105)YGPKWNK(111), was identified in Myb1 in which Gly(106) and Pro(107) were essential for its binding to TvCyP1. Mutation of Gly(106) and Pro(107), respectively, in HA-Myb1 resulted in cytoplasmic retention and elevated nuclear translocation of the overexpressed protein. These results suggest that TvCyP1 may induce the release of Myb1 that is restrained to certain cytoplasmic vesicles prior to its nuclear translocation.

Chlamydia trachomatis infection among female inmates at Briman prison in Saudi Arabia

BACKGROUND

Chlamydia trachomatis infection is the most common sexually transmitted infection (STI) in the western countries; its prevalence in the conservative Muslim population of Saudi Arabia is not known, but it is generally believed to be low. This study is the first to investigate the prevalence of and risk factors for C. trachomatis infection in the high-risk group of female inmates at Briman Prison in Jeddah.

METHODS

The inmates were interviewed using a pre-designed questionnaire, and their urine samples were tested for C. trachomatis infection by real-time PCR assay.

RESULTS

The overall prevalence of C. trachomatis infection was 8.7% in the study population. The ≤25 age group was predominantly affected, with an average prevalence of 16.6%. Two out of five (2/5, 40%) Yamani, (4/33 12.1%) Indonesian, (3/33, 9.1%) Somalian and (2/26, 7.7%) Ethiopian inmates were positive for infection. None of the Saudi inmates (0/14) were positive for infection. Among the studied variables, only age was significantly associated with the infection rate. The other variables (marital status, nationality, religion, employment status, education level, nature of the offense committed, knowledge about protection from STIs, and knowledge about condom use and the purpose of condom use) did not show a significant correlation with Chlamydia infection.

CONCLUSIONS

The overall prevalence of C. trachomatis infection was within the range published by other reports in similar prison settings in developed countries. The results indicate the need for a countrywide screening and treatment program for all inmates at the time of entry into prison.

IL-10 release by bovine epithelial cells cultured with Trichomonas vaginalis and Tritrichomonas foetus

Trichomonas vaginalis and Tritrichomonas foetus are parasitic protists of the human and bovine urogenital tracts, respectively. Several studies have described the cytotoxic effects of trichomonads on urogenital tract epithelial cells. However, little is known about the host cell response against trichomonads. The aim of this study was to determine whether T. foetus and T. vaginalis stimulated the release of the cytokine interleukin (IL)-10 from cultured bovine epithelial cells. To characterise the inflammatory response induced by these parasites, primary cultures of bovine oviduct epithelial cells were exposed to either T. vaginalis or T. foetus. Within 12 h after parasite challenge, supernatants were collected and cytokine production was analysed. Large amounts of IL-10 were detected in the supernatants of cultures that had been stimulated with T. foetus. Interestingly, T. vaginalis induced only a small increase in the release of IL-10 upon exposure to the same bovine cells. Thus, the inflammatory response of the host cell is species-specific. Only T. foetus and not T. vaginalis induced the release of IL-10 by bovine oviduct epithelial cells.

The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs.

Prevalence and incidence of Trichomonas vaginalis infections in women participating in a clinical trial in Durban, South Africa

BACKGROUND AND OBJECTIVES

Trichomonas vaginalis is known to be the most common, curable, sexually transmitted infection among sexually active women and may be associated with the acquisition and transmission of HIV. The purpose of this analysis is to determine the prevalence and incidence of T vaginalis and assess risk factors associated with T vaginalis infection in a cohort of women participating in a clinical trial.

METHODS

We analysed data from women participating in a phase III vaginal diaphragm trial conducted in two communities in Durban, South Africa from 2003 to 2006. A total of 3492 women were screened and 1485 women meeting the respective study eligibility criteria were enrolled. T vaginalis infection was determined at the initial screening visit and at quarterly visits among the enrolled women. Sexual behaviour and sociodemographic data were collected as per the study protocol. Combined data were analysed using STATA V.10.0.

RESULTS

At baseline, prevalence of infection was 6.5%. The overall incident rate was estimated to be 8.6/100 women-years. Prevalent T vaginalis infection was associated with having a concurrent chlamydial infection and incident infections were associated with increased number of sex partners.

CONCLUSIONS

T vaginalis infection was found to be relatively high among this cohort of women. Given the association of this infection with HIV, there is an evident need for T vaginalis screening and treatment in populations at risk for both infections.

Trends and associations of Trichomonas vaginalis infection in men and women with genital discharge syndromes in Johannesburg, South Africa

OBJECTIVES

To better understand the epidemiology of Trichomonas vaginalis infection, we investigated the association between T vaginalis and demographic, clinical, microbiological and behavioural characteristics of patients presenting with genital discharges to a primary healthcare clinic in Johannesburg, South Africa.

METHODS

During six annual surveys (2007-2012), 1218 cases of male urethral discharge syndrome and 1232 cases of vaginal discharge syndrome were consecutively recruited. Diagnostic methods included nucleic acid amplification (Neisseria gonorrhoeae, Chlamydia trachomatis, T vaginalis and Mycoplasma genitalium), microscopy (bacterial vaginosis and Candida) and serology (Treponema pallidum, herpes simplex virus type 2 (HSV-2) and HIV). Logistic regression analyses and χ2 tests were used to identify predictors of T vaginalis infection.

RESULTS

The prevalence of T vaginalis decreased from 2007 to 2012 (men from 13.4% to 4.8%; women from 33.8 to 23.1%). Overall, 74 (6.1%) men and 291 (23.6%) women were T vaginalis positive, with the highest prevalence in those aged ≥40 years (men 13.6%; women 30.9%). T vaginalis infection occurred more often in pregnant women (adjusted OR (aOR) 2.67; 95% CI 1.29 to 5.54) and in women with serological evidence of T pallidum (aOR 1.63; 95% CI 1.08 to 2.45) or HSV-2 infections (aOR 1.75; 95% CI 1.16 to 2.64). T vaginalis infection occurred less often in men with coexistent gonorrhoea (aOR 0.35; 95% CI 0.21 to 0.57) and in women with either bacterial vaginosis (aOR 0.60; 95% CI 0.44 to 0.82) or Candida morphotypes (OR 0.61; 95% CI 0.43 to 0.86).

CONCLUSIONS

Although the prevalence of T vaginalis infection has decreased over time, it remains an important cause of genital discharge in South Africa, particularly in older patients and pregnant women.

Trichomoniasis and HIV interactions: a review

OBJECTIVE

To discuss the epidemiology of Trichomonas vaginalis (TV) and HIV co-infections, the role of TV in acquisition and transmission of HIV, special treatment considerations for TV among women with HIV and the prevention of TV among HIV-infected persons.

DESIGN

Systematic review.

DATA SOURCE

Review of literature of EMBASE and PubMed databases from January 1990 to February 2013. Search keywords included TV, HIV co-infections, HIV acquisition, HIV transmission, HIV shedding, TV treatment, HIV and couples studies.

REVIEW METHOD

We included studies of any design that contained the selected search words and were published during the specified time frame. We then searched the reference lists of included papers for additional papers and included these when relevant.

RESULTS

There is strong evidence that TV increases both transmission and acquisition of HIV among women, and that successful treatment for TV can reduce HIV genital shedding. Single dose metronidazole (MTZ) should no longer be used for HIV+ women with TV given the high rates of asymptomatic bacterial vaginosis co-infections and other factors that may render MTZ less effective in HIV+ women. Prevention of TV among HIV+ persons is similar to among HIV, including promotion of condoms as well as regular screening and prompt treatment. There may be a role for expedited partner treatment for the prevention of repeat infections, but most repeat infections are clinical treatment failures. Diligence in screening and treating TV among both HIV- susceptible and HIV+ persons is an important public health strategy.

Comparison of in vitro activity of metronidazole and garlic-based product (Tomex®) on Trichomonas vaginalis

Trichomonas vaginalis is a common sexually transmitted parasite in humans. Metronidazole has been the gold standard for treatment of trichomoniasis. The prevalence of metronidazole resistance and its unpleasant adverse effects drew the attention to the investigation of other lines of treatment, as that of herbal medicine. Garlic has been proven to have antibacterial, antiprotozoal, and antihelminthic activity. The current study was carried out to evaluate the efficacy of commercially available garlic (Tomex®) on T. vaginalis in vitro. The effect of different concentrations of garlic (12.5, 25, 50, and 100 μg/ml) was determined on multiplication and motility of trophozoites at different time points (after 24, 48, 72, and 96 h) in comparison to the same concentrations of metronidazole at the same different time points. The results showed that parasite multiplication inhibition was noticed in proportion of concentration of Tomex and incubation time. The minimal lethal concentration of Tomex was 100 μg/ml after 24 h, 50 μg/ml after 48 h, 25 μg/ml after 72 h, and 12.5 μg/ml after 96 h. These results were similar to that of metronidazole as its minimal lethal concentration was 50 μg/ml after 24 and 48 h and 12.5 μg/ml after 72 and 96 h. Garlic had completely inhibited the motility of trophozoites with concentration of 100 μg/ml after 24 h, 50 μg/ml after 48 h, 25 μg/ml after 72 h, and 12.5 μg/ml after 96 h while metronidazole had completely inhibited the motility of trophozoites with concentration of 50 μg/ml after 24 h, 25 μg/ml after 48 h, and 12.5 μg/ml after 72 and 96 h. This suggests that commercially available garlic (Tomex®) may be a promising phytotherapeutic agent for trichomoniasis.

Trichomonas vaginalis infection in men who submit self-collected penile swabs after internet recruitment

BACKGROUND

Submission of self-collected penile samples collected at home could remove barriers that men face in getting tested for sexually transmitted infections (STIs).

METHODS

From December 2006 to July 2012, sexually active men aged ≥14 years were recruited by an educational internet program (http://www.iwantthekit.org) which offered free testing for Trichomonas vaginalis infection. Kits were ordered online and swabs were sent via US mail to the laboratory and tested by nucleic acid amplification tests. Demographics and sexual risk factors were accessed by questionnaires. Men called or were contacted to receive their results. Risk factors for trichomonas infection were determined by multivariate logistic regression

RESULTS

Of 4398 men requesting kits, 1699 (38.6%) returned swabs by mail (55.4% returned in 2012). Forty-one percent of men were aged <25 years, 43% were black subjects and 45% were white. The overall prevalence for trichomonas in the 1699 men was 3.7%; the highest prevalence by age group was for men aged 40-49 years (5.2%) and, by year, 216 men screened in 2008 had the highest prevalence (12.5%). Risk factors for 919 men whose risk information was collected by questionnaire (prevalence 6.0%) indicated that 9.6% had a concurrent chlamydia infection. Significantly associated risks factors included: black race (adjusted OR 2.67), residence in Illinois (OR 12.02), age 30-39 years (OR 6.63) and age >40 years (OR 5.31).

CONCLUSIONS

A fairly high prevalence of trichomonas and sexual risk factors were demonstrated from internet recruitment of men. This method of engaging men to get screened for trichomonas may augment screening in STI clinics.

Effect of trichomoniasis therapy on genital HIV viral burden among African women

BACKGROUND

Our objective was to test the hypothesis that treatment for trichomoniasis among HIV-infected women not taking antiretrovirals in South Africa would be associated with decreased HIV genital shedding.

METHODS

HIV-infected women presenting for routine HIV care were screened for trichomoniasis using self-collected vaginal swabs with a rapid point-of-care immunochromatographic antigen test. Women testing positive were offered enrollment into a prospective cohort study, if they had documented HIV infection, were aged 18 to 50 years, and were not receiving antiretroviral therapy. Recent use of postexposure prophylaxis or antibiotic therapy, active genital ulcers, or systemic illness were exclusion criteria. Cervical swabs were collected for gonococcal and chlamydial testing, and those testing positive were excluded. Women were treated with directly observed oral therapy with 2 g of oral metronidazole. A follow-up visit was scheduled 1 month after therapy, and partner letters were provided. Paired cervical wicks and plasma were collected for viral load measurement.

RESULTS

In all, 557 women were screened. Sixty tested positive for trichomoniasis, 10 subsequently met exclusion criteria, and 4 were lost to follow-up. Of 46 women evaluated at follow-up, 37 (80.4%) were cured. Plasma viral load was not significantly different after therapy (P = 0.93). Genital tract viral load decreased by 0.5 log10 (P < 0.01). The mean genital tract viral load (log10) decreased from 4.66 (<3.52-6.46) to 4.18 (<3.52-6.48) (P < 0.01) after therapy.

CONCLUSIONS

Screening and treatment of vaginal trichomoniasis decrease genital shedding of HIV among South African women not receiving antiretrovirals at 1 month after therapy.

The antimicrobial peptide, shrimp anti-lipopolysaccharide factor (SALF), inhibits proinflammatory cytokine expressions through the MAPK and NF-κB pathways in Trichomonas vaginalis adherent to HeLa cells

Trichomonas vaginalis is a parasitic protozoan that causes sexually transmitted infections (STIs) worldwide. The infection is dangerous and easily spreads within a community. Also, some cases of drug resistance were reported. Previously, we reported that the shrimp anti-lipopolysaccharide factor (SALF), an antimicrobial peptide of 24 amino acids, modulates inflammatory responses and inhibits T. vaginalis growth. To date, there is no report on the mechanism of SALF's actions in T. vaginalis' adherence to HeLa cells. In this research using an ELISA, we found that the SALF downregulated the release of proinflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1α, IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1) secreted by T. vaginalis which was adhering to HeLa cells. We also performed real-time PCR experiments to determine the roles of the SALF in the expressions of several proinflammatory genes. Through a Western blot analysis, we determined that SALF treatment inhibited T. vaginalis-treated HeLa cells through the p38 and NF-κB pathways. Furthermore, we used different inhibitors to confirm the pathway by ELISA and Western blotting. Taken together, it is apparent that the SALF suppresses T. vaginalis-induced secretion of proinflammatory cytokines by HeLa cells by acting through the p38 and NF-κB pathways.

Endobiont viruses sensed by the human host - beyond conventional antiparasitic therapy

Wide-spread protozoan parasites carry endosymbiotic dsRNA viruses with uncharted implications to the human host. Among them, Trichomonas vaginalis, a parasite adapted to the human genitourinary tract, infects globally ∼250 million each year rendering them more susceptible to devastating pregnancy complications (especially preterm birth), HIV infection and HPV-related cancer. While first-line antibiotic treatment (metronidazole) commonly kills the protozoan pathogen, it fails to improve reproductive outcome. We show that endosymbiotic Trichomonasvirus, highly prevalent in T. vaginalis clinical isolates, is sensed by the human epithelial cells via Toll-like receptor 3, triggering Interferon Regulating Factor -3, interferon type I and proinflammatory cascades previously implicated in preterm birth and HIV-1 susceptibility. Metronidazole treatment amplified these proinflammatory responses. Thus, a new paradigm targeting the protozoan viruses along with the protozoan host may prevent trichomoniasis-attributable inflammatory sequelae.

Iron-inducible nuclear translocation of a Myb3 transcription factor in the protozoan parasite Trichomonas vaginalis

In Trichomonas vaginalis, a novel nuclear localization signal spanning the folded R2R3 DNA-binding domain of a Myb2 protein was previously identified. To study whether a similar signal is used for nuclear translocation by other Myb proteins, nuclear translocation of Myb3 was examined in this report. When overexpressed, hemagglutinin-tagged Myb3 was localized to nuclei of transfected cells, with a cellular distribution similar to that of endogenous Myb3. Fusion to a bacterial tetracycline repressor, R2R3, of Myb3 that spans amino acids (aa) 48 to 156 was insufficient for nuclear translocation of the fusion protein, unless its C terminus was extended to aa 167. The conserved isoleucine in helix 2 of R2R3, which is important for Myb2's structural integrity in maintaining DNA-binding activity and nuclear translocation, was also vital for the former activity of Myb3, but less crucial for the latter. Sequential nuclear influx and efflux of Myb3, which require further extension of the nuclear localization signal to aa 180, were immediately induced after iron repletion. Sequence elements that regulate nuclear translocation with cytoplasmic retention, nuclear influx, and nuclear efflux were identified within the C-terminal tail. These results suggest that the R2R3 DNA-binding domain also serves as a common module for the nuclear translocation of both Myb2 and Myb3, but there are intrinsic differences between the two nuclear localization signals.

Modeling the impact of Trichomonas vaginalis infection on HIV transmission in HIV-infected individuals in medical care

BACKGROUND

To assess factors associated with having a Trichomonas vaginalis (TV) infection among persons receiving care for human immunodeficiency virus (HIV) and estimate the number of transmitted HIV infections attributable to TV.

METHODS

HIV clinic patients were recruited from 2 secondary prevention studies, screened by urine nucleic-acid amplification tests for sexually transmitted infections, and interviewed about risk factors (baseline, 6, and 12 months). We conducted mathematical modeling of the results to estimate the number of transmitted HIV infections attributable to TV among a cohort of HIV-infected patients receiving medical care in North Carolina.

RESULTS

TV was prevalent in 7.4%, and incident in 2% to 3% of subjects at follow-up. Individuals with HIV RNA <400 copies/mL (odds ratio, 0.32; 95% CI: 0.14-0.73) and at least 13 years of education (odds ratio, 0.24; 95% CI: 0.08-0.70) were less likely to have TV. Mathematical modeling predicted that 0.062 HIV transmission events occur per 100 HIV-infected women in the absence of TV infection and 0.076 HIV infections per 100 HIV- and TV-infected women (estimate range: 0.070-0.079), indicating that 23% of the HIV transmission events from HIV-infected women may be attributable to TV infection when 22% of women are coinfected with TV.

CONCLUSIONS

The data suggest the need for improved diagnosis of TV infection and suggest that HIV-infected women in medical care may be appropriate targets for enhanced testing and treatment.

Prevalence and predictors of sexually transmitted infections in hazardously-drinking incarcerated women

Incarcerated women are at high risk for sexually transmitted infections. Left untreated, these infections can have severe adverse health effects. In this study the authors present prevalence rates of trichomonas, chlamydia, and gonorrhea, and factors related to having a sexually transmitted infection in a sample of 245 hazardously-drinking incarcerated women who reported heterosexual intercourse in the previous 3 months. Vaginal swabs were collected following the self-report baseline assessment. Participants averaged 34.0 (±8.8) years of age; 174 (71.3%) were non-Hispanic Caucasian, 47 (19.3%) were African-American, 17 (7.0%) were Hispanic, and 6 (2.5%) were of other racial or ethnic origins. Twenty-three percent of participants tested positive for chlamydia, trichomonas, or gonorrhea. Being African-American, more frequent sex with a casual partner, and reporting more than one male partner were significantly positively related to sexually transmitted infection, while more frequent sex with a main partner was inversely related. Due to the high rates of infection in this population, jail admission provides a public health opportunity to access a concentrated group of sexually transmitted infectious women. Sexually transmitted infection testing targeted at specific demographic factors, for instance younger age, will miss infected women. Risky sexual partnerships, as well as the benefit of maintaining stable main partnerships may be important topics during sexually transmitted infection prevention interventions.

Access to health services and sexually transmitted infections in a cohort of relocating African American public housing residents: an association between travel time and infection

BACKGROUND

High incidence and prevalence of sexually transmitted infection (STI) in blacks have been attributed to multiple factors. However, few articles have discussed spatial access to healthcare as a driver of disparities. The objective of this analysis was to evaluate the relationship between travel time to a healthcare provider and the likelihood of testing positive for 1 of 3 STIs in a sample of adults living in public housing.

METHODS

One hundred and eight black adults in Atlanta, GA from November 2008 to June 2009, completed a survey that queried sexual behavior and healthcare use and had urine tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis by molecular methods. Travel time was a continuous variable capturing the number of minutes it took to reach the place where participants received most of their care. Multivariate analyses tested the hypothesis that individuals reporting longer travel times would be more likely to test positive for an STI. Travel time was squared to linearize its relationship to the outcome.

RESULTS

Thirty-six residents (37.5%) tested positive for ≥1 STI. A curvilinear relationship existed between travel time and STI status. When travel time was <48 minutes, a positive relationship existed between travel time and the odds of testing positive for an STI. An inverse relationship existed when travel time was ≥48 minutes.

CONCLUSION

Residents of impoverished communities experience a curvilinear relationship between travel time and STI status. We discuss possible factors that might have created this curvilinear relationship, including voluntary social isolation.

Involvement of mast cells in inflammation induced by Trichomonas vaginalis via crosstalk with vaginal epithelial cells

Vaginal epithelial cells (VECs) are thought to function as immune-responsive cells in trichomoniasis, and mast cells have been detected in vaginal smears and the vaginal wall in trichomoniasis. It therefore seemed possible that the VEC-trichomonad reaction might affect the activity of mast cells present in the lamina propria of the vaginal mucosa. In this study, we tested whether culture supernatants of VEC incubated with Trichomonas vaginalis (TCM) could stimulate mast cells. When VECs (MS74) were incubated with live trichomonads, IL-8, IL-6 and MCP-1 expressions increased in the TCM, and mast cells (HMC-1) and human neutrophils migrated more actively towards the TCM. Also, when the TCM was added to mast cells, β-hexosaminidase and cytokines (IL-8 and TNF-α) expressions were increased. Moreover, the culture supernatant of mast cells incubated with TCM (M-TCM) had more increased chemotactic activity for neutrophils than that of TCM. We conclude that inflammatory mediators made by VECs in response to activation by T. vaginalis activate and attract mast cells and then stimulate them to induce neutrophil migration. Our results indicate, for the first time, that VECs play a role in the infiltration of mast cells and neutrophils early in T. vaginalis infection.

The Microbiological Context of HIV Resistance: Vaginal Microbiota and Mucosal Inflammation at the Viral Point of Entry

Immune activation is increasingly recognized as a critical element of HIV infection and pathogenesis, causing expansion of virus founder populations at the mucosal port of entry and eventual exhaustion of cellular immune effectors. HIV susceptibility is well known to be influenced by concurrent sexually transmitted infections; however, the role of commensal vaginal microbiota is poorly characterized. Bacterial vaginosis (BV) is a risk factor for HIV acquisition in studies worldwide; however, the etiology of BV remains enigmatic, and the mechanisms by which BV increases HIV susceptibility are not fully defined. A model of how vaginal microbiota influences HIV transmission is considered in the context of a well-established cohort of HIV-exposed seronegative (HESN) commercial sex workers (CSW) in Nairobi, Kenya, many of whom have increased levels of anti-inflammatory factors in vaginal secretions and reduced peripheral immune activation (immune quiescence). Elucidation of the relationship between complex microbial communities and inflammatory mucosal responses underlying HIV infection should be a priority for future prevention-focussed research.

Molecular testing for Trichomonas vaginalis in women: results from a prospective U.S. clinical trial

Trichomoniasis is a common sexually transmitted disease associated with preterm birth, low birth weight, and increased susceptibility to infection with other pathogenic sexually transmitted microorganisms. Nucleic acid amplification tests for Trichomonas vaginalis have improved sensitivity for detecting infected individuals compared to existing culture-based methods. This prospective, multicenter U.S. clinical trial evaluated the performance of the automated Aptima T. vaginalis assay for detecting T. vaginalis in 1,025 asymptomatic and symptomatic women. Vaginal swab, endocervical swab, ThinPrep PreservCyt, and urine specimens were collected. Subject infection status was determined by wet-mount microscopy and culture. Aptima T. vaginalis assay performance was determined for each specimen type by comparison to subject infection status. Of 933 subjects analyzed, 59.9% were symptomatic. Aptima T. vaginalis clinical sensitivity and specificity were, respectively, 100% and 99.0% for vaginal swabs, 100% and 99.4% for endocervical swabs, 100% and 99.6% in ThinPrep samples, and 95.2% and 98.9% in urine specimens. Aptima T. vaginalis performance levels were similar in asymptomatic and symptomatic subjects. This study validates the clinical performance of the Aptima T. vaginalis assay for screening asymptomatic and symptomatic women for T. vaginalis infection.