Trichomonas vaginalis treatment reduces vaginal HIV-1 shedding

Co-occurrence of Trichomonas vaginalis and bacterial vaginosis among HIV-positive women

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) were examined among human immunodeficiency virus+ women. The prevalence rates were 28.0% for TV, 51.4% for BV, and 17.5% for TV/BV co-infection. Among human immunodeficiency virus+/TV+ women, the rate of BV was 61.0%. Research is needed to examine how BV affects the clinical course and treatment of T. vaginalis.

Patient-delivered partner treatment and Trichomonas vaginalis repeat infection among human immunodeficiency virus-infected women

BACKGROUND

Repeat infections with Trichomonas vaginalis (TV) among human immunodeficiency virus (HIV)-infected women are common and may increase the risk of HIV transmission. Patient delivered partner treatment (PDPT) has been shown to reduce repeat infections of other sexually transmitted diseases. The purpose of this study was to evaluate adherence to PDPT and possible causes of repeat TV infection among HIV-infected women.

METHODS

A multicentered cohort study was conducted in 3 US cities. Women coinfected with HIV and TV were treated with metronidazole and given treatment to deliver to all reported sex partners. A test-of-cure visit was conducted 6 to 12 days post index treatment completion and behavioral data were collected.

RESULTS

Of 252 women (mean age = 40 years, s.d. 9.1) enrolled, 92.5% were black, 26.2% had CD4 cell counts <200/mm(3), 34.1% had plasma viral loads >10,000 copies, 58.3% were taking antiretrovial therapy, and 15.1% had multiple partners. Of the 183 women with partners at baseline, 75.4% provided PDPT to all partners and 61.7% reported they were sure all of their partners took the medication. Factors associated with not giving medications to all partner(s) were multiple sex partners, being single, and having at least one partner unaware of the index woman's HIV status. At test-of-cure, 10.3% were TV-positive and 16.7% reported having sex since baseline. Of the 24 repeat infections, 21 (87.5%) reported adherence to medication and no sexual exposure.

CONCLUSION

HIV-infected women with TV reported high adherence to PDPT, and treatment failure was the most common probable cause of repeat infection.

Trichomonas vaginalis screening and prevention in order to impact the HIV pandemic: Isn't it time we take this infection seriously?

Trichomonas vaginalis (TV) is the second most common sexually transmitted infection (STI) in the world. It is associated with significant morbidity in women: pelvic inflammatory disease (PID), concurrent vaginitis and sexually transmitted infections (STIs), post-operative infection, and pregnancy complications. TV infection has been implicated in HIV acquisition and transmission in men and women. There are multiple mechanisms to explain this association. TV is not routinely screened for in asymptomatic patients; however, infected individuals are most often asymptomatic. Due to the association with the spread of HIV infection, screening should not be limited to symptomatic patients or those seeking treatment for STIs. There are a variety of tests available to detect TV. Treatment of TV has demonstrated lower rates of HIV acquisition in at risk women. In HIV positive men and women, treatment decreases the amount of genital HIV shedding and subsequent infectivity. Initiation of an effective TV screening and treatment program in HIV positive and HIV susceptible populations may limit further transmission of HIV.

Non-sexual transmission of Trichomonas vaginalis in adolescent girls attending school in Ndola, Zambia

OBJECTIVES

To identify risk factors for trichomoniasis among young women in Ndola, Zambia.

METHOD

The study was a cross-sectional study among adolescent girls aged 13-16 years in Ndola, Zambia. Study participants were recruited from schools in selected administrative areas that represented the different socio-economic strata in town. Consenting participants were interviewed about their socio-demographic characteristics; sexual behaviour; and hygiene practices. Self-administered vaginal swabs were tested for Trichomonas vaginalis. HSV-2 antibodies were determined on serum to validate the self-reported sexual activity.

RESULTS

A total of 460 girls participated in the study. The overall prevalence of trichomoniasis was 27.1%, 33.9% among girls who reported that they had ever had sex and 24.7% among virgins. In multivariate analysis the only statistically significant risk factor for trichomoniasis was inconsistent use of soap. For the virgins, none of the risk factors was significantly associated with trichomoniasis, but the association with use of soap (not always versus always) and type of toilet used (pit latrine/bush versus flush toilet) was of borderline significance.

CONCLUSION

We found a high prevalence of trichomoniasis in girls in Ndola who reported that they had never had sex. We postulate that the high prevalence of trichomoniasis in virgins in Ndola is due to non-sexual transmission of trichomoniasis via shared bathing water and inconsistent use of soap.

The influence of bacterial vaginosis on the response to Trichomonas vaginalis treatment among HIV-infected women

OBJECTIVE

Trichomonas vaginalis (TV) is common in HIV+ women, and host factors may play a role in TV treatment outcomes. The purpose of this study was to examine the influence of bacterial vaginosis (BV) on the response to TV treatment among HIV+ women.

METHODS

A secondary analysis was conducted of a clinical trial which randomised HIV+/TV+ women to metronidazole (MTZ) treatment: 2 g (single-dose) versus 7 day 500 mg twice daily (multidose). BV was classified using Nugent scores from baseline Gram stains. Women were recultured for TV at test-of-cure (TOC) and again at 3 months if TV-negative at TOC. Repeat TV infection rates were compared for women with a baseline TV/BV coinfection versus baseline TV infection only, and stratified by treatment arm.

RESULTS

Among 244 HIV+/TV+ women (mean age=40.3, ±9.5; 92.2% African-American), the rate of BV was 66.8%. Women with BV were more likely to report douching and ≥1 recent sex partners. HIV+ women with baseline TV/BV coinfection were more likely to be TV-positive at TOC than women with baseline TV infection only (RR 2.42 (95% CI 0.96 to 6.07; p=0.05)). When stratified by treatment arm, the association was only found in the single-dose arm (p=0.02) and not in the multidose arm (p=0.92). This interaction did not persist at 3 months.

CONCLUSIONS

For HIV+/TV+ women, the rate of BV was high, and BV was associated with early failure of the MTZ single-dose treatment for TV. Biological explanations require further investigation.

Comparison of Aptima Trichomonas vaginalis transcription-mediated amplification assay and BD affirm VPIII for detection of T. vaginalis in symptomatic women: performance parameters and epidemiological implications

Trichomonas vaginalis is an underestimated sexually transmitted infection (STI) associated with numerous clinical sequelae. The true prevalence and clinical impact of trichomoniasis are unknown, as current methods of detection exhibit poor sensitivity compared to molecular amplification methods. Limited data exist comparing the BD Affirm VPIII hybridization assay to the Gen-Probe Aptima T. vaginalis (ATV) transcription-mediated amplification (TMA) assay for detection of T. vaginalis. In this study, specimens from 766 patients were evaluated. Specimens were retrieved consecutively from patients with vaginal complaints and/or with histories suggestive of STI. Study inclusion was dependent upon the request for and collection of both a vaginal swab for Affirm and a specimen for Aptima Combo 2 by the health care provider during the same office visit. Affirm was performed using the specific collection swab and the transport provided for the test. The ATV assay was performed on remnant Aptima Combo 2 specimens. A second ATV TMA assay, utilizing an alternate T. vaginalis primer and probe set, was performed on all specimens positive by the initial TMA and/or the Affirm assay. Infected-patient status was defined as positive T. vaginalis test results by at least 2 assays. Overall, 5.1% of subjects were positive for T. vaginalis. T. vaginalis was most prevalent in women who were 36 to 45 (11.9%), 51 to 60 (7.7%), and 16 to 25 (4.2%) years of age. The ATV assay was statistically more sensitive than the Affirm assay (100% versus 63.4%, P < 0.0001), identifying 36.6% more positive patients.

Interactions of HIV, other sexually transmitted diseases, and genital tract inflammation facilitating local pathogen transmission and acquisition

Despite several decades of clinical trials assessing the impact of etiological treatment of sexually transmitted diseases (STDs) to decrease HIV acquisition and transmission, almost all of these trials have not proven to be efficacious. Increasing evidence suggests that specific STD treatment alone may not be sufficient to alter the genital tract inflammatory milieu that is created by STDs. This paper examines the associations between STDs and HIV susceptibility and infectiousness, and considers the role of chronic and refractory inflammation to create an environment that potentiates HIV and STD transmission and acquisition by reviewing biological, observational, and clinical trial data.

A randomized treatment trial: single versus 7-day dose of metronidazole for the treatment of Trichomonas vaginalis among HIV-infected women

OBJECTIVE

To determine if the metronidazole (MTZ) 2-gm single dose (recommended) is as effective as the 7-day 500 mg twice a day dose (alternative) for treatment of Trichomonas vaginalis (TV) among HIV+ women.

METHODS

Phase IV randomized clinical trial; HIV+ women with culture confirmed TV were randomized to treatment arm: MTZ 2-gm single dose or MTZ 500 mg twice a day 7-day dose. All women were given 2-gm MTZ doses to deliver to their sex partners. Women were recultured for TV at a test-of-cure (TOC) visit occurring 6-12 days after treatment completion. TV-negative women at TOC were again recultured at a 3-month visit. Repeat TV infection rates were compared between arms.

RESULTS

Two hundred seventy HIV+/TV+ women were enrolled (mean age = 40 years, ±9.4; 92.2% African American). Treatment arms were similar with respect to age, race, CD4 count, viral load, antiretroviral therapy status, site, and loss-to-follow up. Women in the 7-day arm had lower repeat TV infection rates at TOC [8.5% (11 of 130) versus 16.8% (21 of 125) (relative risk: 0.50, 95% confidence interval = 0.25, 1.00; P < 0.05)] and at 3 months [11.0% (8 of 73) versus 24.1% (19 of 79) (relative risk: 0.46, 95% confidence interval = 0.21, 0.98; P = 0.03)] compared with the single-dose arm.

CONCLUSIONS

The 7-day MTZ dose was more effective than the single dose for the treatment of TV among HIV+ women.

Trichomonas vaginalis prevalence, incidence, risk factors and antibiotic-resistance in an adolescent population

OBJECTIVE

To determine the prevalence and incidence of trichomoniasis, risk factors for infection, and the prevalence of metronidazole and tinidazole-resistant Trichomonas vaginalis (T. vaginalis) in female adolescents.

METHODS

Nonpregnant, HIV-seronegative, sexually active females (13-19 years) visiting an inner city public primary care clinic were tested for T. vaginalis by wet mount and culture, and interviewed about risk-taking behavior every 6 months. Infected patients were treated with a 2 g oral dose of metronidazole. Isolates from positive T. vaginalis cultures were tested for in vitro resistance to metronidazole and tinidazole.

RESULTS

Among 467 study participants, 67 (14.4%; 95% confidence interval, 11.3-17.5) were diagnosed with trichomoniasis at first T. vaginalis culture. Significant risk factors for T. vaginalis infection were having an older sex partner and concurrent Neisseria gonorrhoeae infection. The incidence was 22.1 cases per 100 person-years. Among 42 participants who had a prevalent infection and returned for followup, 13 (31.0%) had at least 1 more episode of trichomoniasis. Resistance testing was completed for 78 isolates: 37 at first visit and 41 during follow-up. One (2.7%; 95% confidence interval, 0.07-14.2) of the 37 first-visit isolates was moderately resistant to metronidazole (minimal lethal concentration = 200 microg/mL). Of the 41 follow-up visit isolates, 1 was moderately resistant to metronidazole and 2 had borderline resistance (minimal lethal concentration = 50 microg/mL). The prevalence of tinidazole resistance was 0% (0.0%-9.5%).

CONCLUSION

The study population had high prevalence and incidence of trichomoniasis. The prevalence of antibiotic-resistant T. vaginalis among female adolescents was low.

Screening for Trichomonas vaginalis in high-risk adolescent females with a new transcription-mediated nucleic acid amplification test (NAAT): associations with ethnicity, symptoms, and prior and current STIs

PURPOSE

The importance of diagnosing trichomoniasis is highlighted by its strong association with HIV acquisition and viral shedding. The low sensitivity of wet preparation and often asymptomatic nature of trichomoniasis results in failure to recognize and treat this sexually transmitted infection. The purpose of this study was to evaluate the feasibility of screening high-risk adolescent females using a new highly sensitive and specific NAAT assay.

METHODS

We enrolled a consecutive, clinical sample of 144 sexually active females, aged 13 through 21. Subjects completed a questionnaire on sexual history and current vaginal symptoms, and provided two self- or physician-collected vaginal swabs and urine. A wet preparation test was performed with one swab and the APTIMA Trichomonas vaginalis (ATV) assay (Gen-Probe, Inc.) was performed with the other and with urine.

RESULTS

Mean age was 18 +/- 1.6 years; 55% Hispanic and 35% black. A three-fold higher prevalence of trichomoniasis (6.3%) was detected by ATV than by wet preparation (2.1%) with 100% concordance between vaginal swab and urine. Prevalence of chlamydia by APTIMA was 11%; no gonorrhea was detected. Subjects with trichomoniasis were more likely than those without to be black (P < 0.01), and to report past gonorrhea (P < 0.01) and past PID (P < 0.001). No vaginal symptom distinguished those with trichomoniasis.

CONCLUSION

Three times as many cases of trichomoniasis were identified with ATV compared to wet preparation and identical results were obtained with vaginal swabs and urine. No symptoms were associated with trichomoniasis. These findings highlight the imperative and feasibility of screening and treating at-risk populations.

Identification and characterization of a surface-associated, subtilisin-like serine protease inTrichomonas vaginalis

Trichomonas vaginalisis a protozoan parasite causing trichomonosis, a sexually transmitted infection in humans. This parasite has numerous proteases, most of which are cysteine proteases that appear to be involved in adherence and cytotoxicity of host cells. In this report we identify and characterize a putative subtilisin-like serine protease (SUB1). Thesub1gene encodes a 101-kDa protein.In silicoanalyses predict signal and pro-peptides at the N-terminus, and a transmembrane helix at the carboxy-terminal region. Thesub1gene was found as single copy by Southern analysis, albeit additional serine protease related genes are annotated in theT. vaginalisgenome. The expression ofsub1could only be detected by RT-PCR and Ribonuclease Protection Assays, suggesting a low abundant mRNA. Thesub1gene transcription start site was correctly assigned by RPA. The transcript abundance was found to be modulated by the availability of iron in the growth medium. Antibodies raised to a specific SUB1 peptide recognized a single protein band (~82 kDa) in Western blots, possibly representing the mature form of the protein. Immunofluorescence showed SUB1 on the trichomonad surface, and in dispersed vesicles throughout the cytoplasm. A bioinformatic analysis of genes annotated as serine proteases in theT. vaginalisgenome is also presented. To our knowledge this is the first putative serine protease experimentally described forT. vaginalis.

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

BACKGROUND

To estimate the association between Trichomonas vaginalis infection (TV) and 6 sexually transmitted infections: chlamydia, gonorrhea, herpes simplex virus (Types 1 and 2), syphilis, and human immunodeficiency virus (HIV) in a nationally representative sample.

METHODS

We used data from the National Health and Nutrition Examination Survey combining the 2001-2002 and 2003-2004 waves to estimate the association between TV and sexually transmitted infections (STIs) among women in the civilian, noninstitutionalized US population. The final sample included data from 3648 women, which when weighted, represents the experience of 65,563,298 US women between the ages of 14 and 49. Crude and adjusted relative risks were estimated using logistic regression for rare STIs (<10%; chlamydia, syphilis, and HIV) and Poisson regression for common STIs (herpes simplex virus [HSV] Types 1 and 2). Statistical analyses were conducted using Stata (version 9.2).

RESULTS

The prevalence of trichomoniasis was 3.2% with over 80% of cases asymptomatic in the past month. All STIs examined (chlamydia, gonorrhea, HSV-1, HSV-2, syphilis, and HIV) were more common among women with a positive test for trichomoniasis. HSV-1 (RR = 1.20, 95% CI: 1.09, 1.34) and HSV-2 (RR = 1.51, 95% CI: 2.32, 3.23) were significantly associated with trichomoniasis after adjusting for race/ethnicity, age, and recent sexual partners. In crude analyses, a positive treponemal test was 6 times (95% CI: 2.07, 18.8) more common and HIV was 13 times (95% CI: 2.88, 59.1) more common among women with trichomoniasis, but these estimates were greatly attenuated after adjustment for potential confounders.

CONCLUSION

Trichomoniasis is significantly associated with concurrent STI.

Trichomoniasis in teens: an update

PURPOSE OF REVIEW

Trichomoniasis, caused by the protozoa Trichomonas vaginalis, is one of the oldest sexually transmitted infections. Since the advent of more accurate diagnostic tests, the epidemiology and consequences of infection with T. vaginalis can be described more precisely. This review will highlight new diagnostic methods, the epidemiology of trichomoniasis, and discuss the merits of improved screening for this pathogen in adolescent women.

RECENT FINDINGS

Interest in trichomoniasis has renewed due to evidence that trichomoniasis is more common than gonorrhea in adolescent women, is often asymptomatic, may persist for several months, and may be confused with bacterial vaginosis. In addition, trichomoniasis is linked to pelvic inflammatory disease and can increase one's susceptibility to viruses such as herpes, human papillomavirus, andHIV.

SUMMARY

Clinicians who use better diagnostic methods and offer more widespread testing will identify more infections and reduce the epidemic of this easily treated infection. Early diagnosis provides the opportunity to reduce transmission and potentially prevent future complications.

Efficient methodologies for sensitive HIV-1 RNA quantitation from plasma and vaginal secretions

BACKGROUND

Quantifying HIV levels in mucosal secretions is essential to study compartmentalized expression of HIV and facilitate development of intervention strategies to prevent disease progression and transmission.

OBJECTIVES

To develop a sensitive, reliable, and cost-effective technique to quantify HIV from blood and vaginal secretions that is compatible with efficient implementation in clinical research environments.

STUDY DESIGN

A sensitive, reliable, internally-controlled real-time reverse transcriptase (RT) PCR assay, which uses the HIV-1 pol gene as a target (Hpol assay) was developed to quantify HIV levels in plasma and genital secretions, and compared to the widely used Roche Amplicor HIV-1 Monitor assay. In addition, a simplified method of sample collection and processing of genital secretions (self-collection and use of RNAlater with batch processing) was compared to provider collection of samples and immediate processing.

RESULTS

The sensitivity and reliability of HIV levels detected by the assay described herein correlate well with measurements from Roche Amplicor HIV-1 Monitor assay for both plasma and vaginal secretions (R(2)=0.9179 and R(2)=0.942, respectively). The Hpol assay reproducibly quantifies a lower limit of 5 HIV-1 RNA copies per reaction, with low-levels of inter-assay and intra-assay variation. Additionally, vaginal viral levels and detection frequency did not differ significantly between the two the collection and processing methods.

CONCLUSIONS

The methodologies developed here provide sensitive, reliable, and cost-effective quantification of HIV levels in plasma and mucosal secretions, and are compatible with efficient use in clinical research studies.

The mercaptopyruvate sulfurtransferase of Trichomonas vaginalis links cysteine catabolism to the production of thioredoxin persulfide

Trichomonas vaginalis is a protozoan parasite of humans that is able to synthesize cysteine de novo using cysteine synthase but does not produce glutathione. In this study, high pressure liquid chromatography analysis confirmed that cysteine is the major intracellular redox buffer by showing that T. vaginalis contains high levels of cysteine ( approximately 600 mum) comprising more than 70% of the total thiols detected. To investigate possible mechanisms for the regulation of cysteine levels in T. vaginalis, we have characterized enzymes of the mercaptopyruvate pathway. This consists of an aspartate aminotransferase (TvAspAT1), which transaminates cysteine to form 3-mercaptopyruvate (3-MP), and mercaptopyruvate sulfurtransferase (TvMST), which transfers the sulfur of 3-MP to a nucleophilic acceptor, generating pyruvate. TvMST has high activity with 3-MP as a sulfur donor and can use several thiol compounds as sulfur acceptor substrates. Our analysis indicated that TvMST has a k(cat)/K(m) for reduced thioredoxin of 6.2 x 10(7) m(-1) s(-1), more than 100-fold higher than that observed for beta-mercaptoethanol and cysteine, suggesting that thioredoxin is a preferred substrate for TvMST. Thiol trapping and mass spectrometry provided direct evidence for the formation of thioredoxin persulfide as a product of this reaction. The thioredoxin persulfide could serve a biological function such as the transfer of the persulfide to a target protein or the sequestered release of sulfide for biosynthesis. Changes in MST activity of T. vaginalis in response to variation in the supply of exogenous cysteine are suggestive of a role for the mercaptopyruvate pathway in the removal of excess intracellular cysteine, redox homeostasis, and antioxidant defense.

Genetic identity and differential gene expression between Trichomonas vaginalis and Trichomonas tenax

BACKGROUND

Trichomonas vaginalis is a human urogenital pathogen responsible for trichomonosis, the number-one, non-viral sexually transmitted disease (STD) worldwide, while T. tenax is a commensal of the human oral cavity, found particularly in patients with poor oral hygiene and advanced periodontal disease. The extent of genetic identity between T. vaginalis and its oral commensal counterpart is unknown.

RESULTS

Genes that were differentially expressed in T. vaginalis were identified by screening three independent subtraction cDNA libraries enriched for T. vaginalis genes. The same thirty randomly selected cDNA clones encoding for proteins with specific functions associated with colonization were identified from each of the subtraction cDNA libraries. In addition, a T. vaginalis cDNA expression library was screened with patient sera that was first pre-adsorbed with an extract of T. tenax antigens, and seven specific cDNA clones were identified from this cDNA library. Interestingly, some of the clones identified by the subtraction cDNA screening were also obtained from the cDNA expression library with the pre-adsorbed sera. Moreover and noteworthy, clones identified by both the procedures were found to be up-regulated in expression in T. vaginalis upon contact with vaginal epithelial cells, suggesting a role for these gene products in host colonization. Semi-quantitative RT-PCR analysis of select clones showed that the genes were not unique to T. vaginalis and that these genes were also present in T. tenax, albeit at very low levels of expression.

CONCLUSION

These results suggest that T. vaginalis and T. tenax have remarkable genetic identity and that T. vaginalis has higher levels of gene expression when compared to that of T. tenax. The data may suggest that T. tenax could be a variant of T. vaginalis.