Targeted screening for Trichomonas vaginalis with culture using a two-step method in women presenting for STD evaluation

OBJECTIVES: Trichomonas vaginalis is the most common nonviral sexually transmitted pathogen. Wet mount microscopy performs poorly compared with culture; however, universal screening using culture would be cost-prohibitive. GOAL: The goal of this study was to develop a predictive model for wet mount-negative women who may benefit from targeted use of culture for T. vaginalis detection. STUDY: Women presenting for sexually transmitted disease evaluation were prospectively screened for trichomoniasis using wet mount and culture. Multivariate logistic regression was used to identify predictors of culture-proven trichomoniasis among wet mount-negative women. RESULTS: A total of 2194 women were screened for trichomoniasis; overall, the prevalence of T. vaginalis was 17.5%. Three predictors (any drug use, contact to trichomoniasis, and African-American race) provided the most specific model (100%); any 1 predictor, the most sensitive model (97.8%). CONCLUSIONS: Given the public health impact of trichomoniasis, we recommend using any 1 of 3 predictors to identify women who would benefit from targeted culture for T. vaginalis.     

Comparison of a TaqMan-based real-time polymerase chain reaction with conventional tests for the detection of Trichomonas vaginalis

OBJECTIVE: To compare a TaqMan-based real-time polymerase chain reaction (PCR) with conventional PCR, culture, and wet-mount microscopy for the diagnosis of trichomoniasis in women. METHODS: Vaginal swabs from 119 women were tested for Trichomonas vaginalis by wet mount and culture. Paired vaginal lavage and urine specimens were tested by conventional and real-time PCR. RESULTS: Using an expanded "gold standard", defined as a positive culture result using vaginal swabs and/or a positive PCR test using TVK3/7 primers, the overall prevalence of T vaginalis in the study population was 65.5% (78/119). The detection rate of T vaginalis was 65.5% (78/119) and 36.9% (44/119) by conventional PCR using vaginal washings and urine specimens, respectively; 68.9% (82/119) by real-time PCR using vaginal washings and 61.3% (73/119) by real-time PCR using urine specimens. The sensitivities of conventional PCR using vaginal washings and urine and real-time PCR using vaginal washings and urine, compared with the gold standard were 100%, 56.4%, 100% and 76.7%, and the specificities of these tests were 100%, 97.6%, 82.9% and 97%, respectively. CONCLUSIONS: The real-time PCR test proved to be significantly more sensitive than culture and wet-mount microscopy, although its specificity was slightly lower than these tests. In addition, it was more sensitive, rapid and less time consuming than conventional PCR for the detection of T vaginalis.     

Ignored trichomonal infestation diagnosed by Papanicolaou smear.

OBJECTIVE--To compare the occurrence of Trichomonas vaginalis as demonstrated by culture and by Papanicolaou (PAP) smears in a sexually transmitted disease (STD) clinic. SETTING--The largest out-patient venereological clinic in Denmark. SUBJECT AND METHODS--As the prevalence of trichomonal infestation has decreased considerable in recent years direct microscopy of vaginal wet mounts is no longer performed routinely. Instead the screening diagnostic procedure is based on culture. We have retrospectively collected data on culture-negative women with Trichomonas vaginalis organisms present in cervical smears, taken on a routine basis to exclude atypical cells, and compared with the clinical findings. RESULTS--Since 1992 a total of 17 women were found to harbour Trichomonas vaginalis in cervical smear. A vaginal discharge was described in 10 women, six of whom had concomittant unspecific vaginitis. However, four women had unexplained vaginal discharge that could have been related to infestation with Trichomonas vaginalis. In addition one asymptomatic woman had a male partner with persistent urethritis. CONCLUSION--The prevalence of trichomoniasis is underestimated in women attending the clinic if the diagnosis is based on culture alone. PAP smears may be helpful in demonstrating characteristic trichomonal organisms. In general we do not recommend the PAP smear be used to diagnose STDs. However the finding of trichomanal organisms in smears should prompt a repeated culture and direct microscopy of vaginal wet mount.     

A clinical evaluation of trichomoniasis in San Jose, Costa Rica using the InPouch TV test.

OBJECTIVE--to determine the prevalence of trichomoniasis in San Jose, Costa Rica, comparing two methods, the InPouch TV test and the saline wet mount. METHODS--One hundred symptomatic and asymptomatic female patients at two hospitals and at a sexually transmitted disease (STD) clinic were evaluated. Vaginal discharge was the most prevalent genitourinary abnormality among symptomatic patients. The patients were between 18 and 70 years old. Fifty-seven were from the STD clinic, 43 from the two hospitals. A saline wet mount and a culture were taken from each patient. The culture employed a new procedure for diagnosis of trichomonads, the InPouch TV test (BioMed Diagnostics, San Jose, CA). RESULTS--Thirteen of the 100 patients were culture positive, two of whom were wet mount positive. No wet mount positives were culture negative. Eleven of the positive tests were from the STD clinic and two were from the hospitals. CONCLUSIONS--The results of this initial epidemiologic study indicate a prevalence of 19% for trichomoniasis in the STD clinic population and 4.6% in the hospitals group. Trichomonas vaginalis was not diagnosed by laboratory methods prior to this study. The InPouch TV test has a selective fungicidal and bactericidal, enriched proteose-peptone medium which provides a sensitivity of 4 organisms per ml and a 1 year shelf life at room temperature. This in vitro culture test demonstrated unique capabilities as a transport and culture medium. Its procedure offers simplicity in application and an excellent visualisation of trichomonads.     

Comparison of direct fluorescent antibody, acridine orange, wet mount, and culture for detection of Trichomonas vaginalis in women attending a public sexually transmitted diseases clinic

To define the performance characteristics of two newer tests for Trichomonas vaginalis (TV), the authors compared direct fluorescent antibody (DFA) (mixed monoclonal antibody, Integrated Diagnostics, Inc, Berkeley, CA) and acridine orange (AO) tests to standard wet mount (WM) preparations and culture (modified Diamond medium) of vaginal wash specimens in consecutively examined women presenting to a public sexually transmitted diseases (STD) clinic. Cultures for Neisseria gonorrhoeae (GC), Chlamydia trachomatis (CT), and yeast were also performed on all patients. Of 104 women, 59 (57%) were infected with one or more pathogens. Trichomonas vaginalis was detected by WM and/or culture in 38 (37%) women and was the most prevalent infection. Of the 38 patients with TV, 95% were detected by culture, 83% by DFA, 66% by AO, and 66% by WM. An additional patient was DFA positive but negative for TV by all other methods. The sensitivity of DFA was superior to AO and WM in women with TV infection alone (96% compared to 67% and 53%, respectively). It was comparable to AO and WM in women with multiple infections (67% compared to 53% and 73%). Even in the presence of other pathogens, DFA appears to be a reasonable alternative to culture for detection of TV. In addition, DFA is rapid, easy to perform, and relatively inexpensive.     

Trichomonal vaginitis: evaluation of serological tests and identification of immunoreactive surface peptides.

An indirect haemagglutination assay (IHA) with polysaccharide and protein antigens of Trichomonas vaginalis and an enzyme linked immunosorbent assay (ELISA) were used to test for antibodies against T vaginalis in 58 women with trichonomal vaginitis and 48 with non-specific vaginitis. Eleven antibody positive sera were used in a radioimmunoprecipitation assay (RIPA) to identify surface peptides that elicited antibody responses in infected women. The serological tests were less sensitive than biological tests (smear examination and culture); antibodies were detected in 22 of the 58 women with trichomonal vaginitis by IHA using polysaccharide as antigen, in 27 by IHA using protein antigen, and in 36 by ELISA. The ELISA was also found to be of low specificity. Only two of the 11 sera tested by RIPA showed positive reactions with surface antigens, which were confirmed by autoradiography.     

Prevalence of Trichomonas vaginalis in a male sexually transmitted disease clinic population by interview, wet mount microscopy, and the InPouch TV test.

OBJECTIVE--To determine the prevalence of trichomoniasis in male patients from their urine at a Sexually Transmitted Disease (STD) Clinic using the InPouch TV culture system. METHODS--Two hundred and four patients were examined for STD infections. Their ages ranged between 17 and 72 years. Depending on their clinical symptoms tests were ordered for Neisseria gonorrhoeae, chlamydia, and for syphilis. Each patient submitted a clean catch urine specimen for trichomonas testing. A 15 ml aliquot of urine was centrifuged and a drop of the sediment examined microscopically. The remainder was cultured in the InPouch TV test. Each pouch was examined at 24 h, 48 h, and 5 days. RESULTS--Twenty-four of the 204 patients (12%) were culture positive for Trichomonas vaginalis and only three of these were wet mount positive. CONCLUSION--The InPouch TV test demonstrated an epidemiological important infected male population that was not indicated by wet mount microscopy.     

巢式聚合酶链反应检测男性尿道炎患者尿液中阴道毛滴虫

目的 建立两种巢式聚合酶链反应（PCR）方法检测男性尿道炎患者尿液中阴道毛滴虫感染状况,评价两种巢式PCR在临床诊断中的应用价值。 方法 2011年4月至2013年12月来我院性病门诊就诊的1 088例男性尿道炎患者为研究对象,收集尿道拭子标本做分泌物涂片镜检、阴道毛滴虫湿片检测以及淋球菌培养,同时收集尿液标本提取DNA,针对阴道毛滴虫重复基因组和β微管蛋白基因,采用两种巢式PCR法检测尿液中阴道毛滴虫。 结果 湿片法检测阴道毛滴虫的阳性率为0,而两种巢式PCR法均检测出29例阳性标本,阳性率为2.67%,且两种巢式PCR法检测出的阳性标本一致。 结论 与湿片法相比,巢式PCR法检测男性尿液标本阴道毛滴虫具有较高的灵敏度和特异性。     

Comparison of latex agglutination, wet preparation, and culture for the detection of Trichomonas vaginalis

Objectives: To compare the performance of three diagnostic methods for Trichomonas vaginalis infection—latex agglutination, saline wet mount, and culture.

Methods: Vaginal swabs from 3807 women attending antenatal clinics were tested for the presence of T vaginalis by latex agglutination. All positives and the following two negatives were tested by wet preparation and culture.

Results: The prevalence of infection by latex agglutination was 5.4%. Using an expanded gold standard based on the wet mount and culture results, the sensitivity of the latex agglutination test was 98.8% (95% CI 95.9 to 99.9) and specificity was 92.1 (89.2 to 94.5). The kappa index for test agreement was 0.93 for latex and culture and 0.88 for latex and wet preparation.

Conclusion: The latex agglutination test is a highly sensitive test for detecting T vaginalis infection. It is a simple rapid test and has the potential for use in screening and diagnostic settings.

     

Lack of evidence for the involvement of rectal and oral trichomonads in the aetiology of vaginal trichomoniasis in Ghana

OBJECTIVE: To investigate the possible involvement of human trichomonads (Pentatrichomonas hominis and Trichomonas tenax) other than Trichomonas vaginalis in the aetiology of vaginal trichomoniasis. METHODS: Vaginal swabs taken from women attending antenatal clinics were tested for Trichomonas vaginalis by traditional assays (wet-mount microscopy and InPouch culture) and nucleic acid amplification (polymerase chain reaction). These swabs were also tested for the presence of P hominis and T tenax by nucleic acid amplification. Oral and rectal swabs from these women were tested for T tenax and P hominis respectively. Data on sociodemographic characteristics, sexual and anogenital hygiene practices likely to seed P hominis and T tenax into the vagina were collected by a questionnaire. RESULTS: 93% (161) of the 173 samples in which T vaginalis was detected by wet preparation or culture was evaluable by PCR. Of this, T vaginalis was detected in 94% (152) by T vaginalis-specific PCR. Neither P hominis nor T tenax was detected in any of the vaginal swab samples. These included nine samples for which T vaginalis had been detected by wet preparation or culture, but were negative by T vaginalis nucleic acid amplification. P hominis and T tenax were not detected in any of the rectal and oral swabs, respectively. CONCLUSION: In this group of women, there was no evidence for the involvement of trichomonads other than T vaginalis in the aetiology of vaginal trichomoniasis.     

A novel method to increase the viability of Trichomonas vaginalis in urine

OBJECTIVES: Two of the major diagnostic methods for Trichomonas vaginalis, wet mount and culture, rely on the continued viability of the organism. Methods to increase the viability of T. vaginalis in urine are needed. GOAL: The goal of this study was to develop a method that increases the time of viability of T. vaginalis in urine. STUDY DESIGN: Urine samples were inoculated with trichomonads, held at either room temperature or 37 degrees C, and processed through a column and frit, which was then placed in either a tube of culture medium containing antibiotics or a TV InPouch. RESULTS: The column and polyethylene frit system was found to increase the duration of viability for T. vaginalis from urine specimens at least 6-fold. CONCLUSION: This novel method, which uses a column and frit system to increase the duration of viability of the organism, has the potential to increase the sensitivity of diagnostic tests.     

泌尿生殖道中阴道毛滴虫的检测

目的:探讨适合于检测男、女两性泌尿生殖道中阴道毛滴虫(TV)的取材方式和检验方法,以提高TV的阳性检出率。方法:对211例患者的尿道(阴道)分泌物和尿液采用湿片观察、培养法和湿片+培养法分别进行TV的对照检测。结果:在138例男性患者中泌尿生殖道共检出TV 18例(13.0％),在73例女性患者中泌尿生殖道共检出TV 49例(67.1％)。男性患者尿液和尿道分泌物培养法对TV的检出率差异无显著性(x2=133,P>0.05);女性患者阴道分泌物培养后TV检出率显著高于尿液的TV检出率(x2=19.4,P<0.005)。培养法、湿片+培养法与湿片观察相比,女性阴道分泌物中TV的检出率差异均有显著性(x2=4.17,P<0.05;x2=5.14,P<0.05)。女性尿液培养检测TV的敏感性和特异性最低(48.9％,96.2％)。结论:男性滴虫性尿道炎可采用尿液检测TV,在女性患者检测TV可采用湿片+培养法,该方法可作为性传播性疾病(STD)高危人群筛检TV感染的方法。     

Trichomonas vaginalis as a cause of urethritis in Malawian men.

BACKGROUND AND OBJECTIVES: Trichomonas vaginalis is one of the most common sexually transmitted infections. In Malawi, rates of trichomoniasis in women are high. The prevalence of T. vaginalis infection in men is expected to be high but has not previously been documented. GOALS: We sought to determine the prevalence of trichomoniasis in Malawian men with and without urethritis, to evaluate a polymerase chain reaction detection assay for T. vaginalis in urethral swabs and to examine the effect of T. vaginalis infection on excretion of human immunodeficiency virus (HIV) in semen. STUDY DESIGN: Men presenting at the Sexually Transmitted Diseases (STD) and Dermatology Clinics in Malawi were enrolled in a cross-sectional study. We compared a polymerase chain reaction-based test for T. vaginalis detection with wet-mount microscopy and culture of urethral swabs. HIV serology was determined by enzyme-linked immunosorbent assay (ELISA), and HIV-1 RNA concentrations in semen were measured by quantitative nucleic acid sequence-based analysis. RESULTS: T. vaginalis was detected in 51 of 293 men. The estimated prevalence among symptomatic men was 20.8% and among asymptomatic men, 12.2%. Polymerase chain reaction performed with a sensitivity of 0.82 (95% CI: 0.66-0.92) and specificity of 0.95 (95% CI: 0.91-0.97) compared to wet-mount microscopy and culture. There was no difference in the rate of HIV seropositivity in men with and without T. vaginalis infection. However, in men with symptomatic urethritis, the median HIV RNA concentration in seminal plasma from men with T. vaginalis was significantly higher that in seminal plasma from HIV-positive men without trichomonas.     

A comparison of yield from cervix versus vagina for culturing Candida albicans and Trichomonas vaginalis.

OBJECTIVE--To determine the agreement of culture results of Candida albicans and Trichomonas vaginalis from the cervix versus posterior fornix in women with vaginal symptoms. DESIGN--Same patient comparison of culture results from two sample sites. SETTING--Twenty one general practices in Amsterdam and the east of the Netherlands. SUBJECTS--Six hundred and eighty two women aged 15 to 55 years with vaginal symptoms, seen between 1 October 1987 and 31 May 1990. MAIN OUTCOME MEASURES--For each site (cervix and posterior fornix) the proportion of detected C albicans and T vaginalis. The sensitivity of the cervical swab related to the vaginal one. The percentage of concordance for both microorganisms. RESULTS--In 248 (34%) women C albicans was diagnosed and in 38 (6%) T vaginalis. In 99% of the proven C albicans cases, the yeast was found in the vagina. In 94% C albicans was isolated from the cervix. Sensitivity of the cervical swab was 94%. In 98% of the patients a concordant observation was made regarding detection of yeast. In 97% of the proven T vaginalis cases the protozoon was found in the vagina. In 91% T vaginalis was detected from the cervical swab. Sensitivity of the cervical swab was 92%. The culture results were concordant in 99%. CONCLUSION--The yield from the vaginal source was slightly better than that from the cervix for culture of both microorganisms. For screening purposes, specimen-collection for culture of N gonorrhoeae, C albicans and T vaginalis can be combined in one swab taken from the cervix.     

The tampon test for trichomoniasis: a comparison between conventional methods and a polymerase chain reaction for Trichomonas vaginalis in women

OBJECTIVES: Trichomonas vaginalis is the most common STD worldwide and the infection has been linked with an increased risk of HIV transmission. We present a detailed comparison between conventional collection and testing methods and the polymerase chain reaction (PCR) tampon test for T vaginalis. METHODS: Women were tested for the presence of T vaginalis by PCR analysis of a tampon specimen and by conventional methods which included one or more of the following: culture and microscopy from a high vaginal swab (HVS) or endocervical swab (ECS), and microscopy of a Papanicolaou (Pap) smear. RESULTS: T vaginalis was detected in 51/590 (8.6%) conventional tests and 93/590 (15.8%) tampon specimens. Retesting of all tampon PCR positive specimens confirmed 89/93 (95.7%) tests. Using the tampon PCR as the reference, the sensitivities of the different conventional sampling and testing methods for the detection of T vaginalis were 8.3% (5/60) for ECS microscopy or culture, 31% (13/42) for HVS microscopy or culture, 52.8% (19/36) for HVS directly inoculated into Trichomonas medium and 59.4% (38/64) for Pap smear. CONCLUSIONS: No conventional test in the remote setting has comparable sensitivity to PCR. The Pap smear is the next most sensitive, but requires a speculum examination. The use of PCR will allow inclusion of T vaginalis into STD screening programmes in both developed (lower prevalence) and developing (higher prevalence) countries.


     

An evaluation of an InPouch TV culture method for diagnosing Trichomonas vaginalis infection.

A new culture method for Trichomonas vaginalis, the InPouch TV test, was evaluated for its sensitivity and specificity in supporting growth of trichomonads. Five clinical isolates remained viable for periods from 41 to 131 days. A strain from the ATTC 30001 remained viable for 91 days. As few as four trichomonads/ml of culture medium could be viewed microscopically within 24 h. Doubling time for growth of trichomonad varied between 5 to 8 h. In a clinical study of 102 wet-mount negative specimens, 15 culture positive patients were observed with the InPouch TV test compared with 12 of the same patients with Hollander's fluid medium.     

Enzyme linked immunosorbent assay for detecting antibody to Trichomonas vaginalis: use of whole cells and aqueous extract as antigen.

An enzyme linked immunosorbent assay (ELISA) for detecting antibody to antigenic Trichomonas vaginalis macromolecules has been identified using whole cells or an aqueous protein extract as antigen. The test was developed under optimum conditions using serum samples from experimental animals. The sensitivity of the ELISA was equal to or greater than that obtained by radioimmunoprecipitation and electrophoresis-fluorography techniques. The ELISA was capable of assessing antibody responses during the development of lesions in animals inoculated subcutaneously and it reproducibly measured the individual classes immunoglobulins directed at T vaginalis. The colorimetric assay was also suitable for showing cross reactivity between trichomonal species as well as between different strains of T vaginalis. Conditions established for monitoring antibody to trichomanads in immunised rabbits or infected mice were equally effective for human materials, such as serum or vaginal washes. Serum from experimental animals or infected people showed high concentrations of IgG, IgA, and IgM antibody to trichomonads. Only antibodies of the IgG and IgA class were detected in vaginal washes from women with acute trichomoniasis. No IgE antibody to trichomonads was found under a variety of conditions in serum samples from patients or experimental animals.     

Trichomoniasis: clinical manifestations, diagnosis and management

Trichomonas vaginalis was originally considered a commensal organism until the 1950s when the understanding of its role as a sexually transmitted infection (STI) began to evolve. Trichomoniasis has been associated with vaginitis, cervicitis, urethritis, pelvic inflammatory disease (PID), and adverse birth outcomes. Infection with T vaginalis could have an important role in transmission and acquisition of HIV. T vaginalis is site specific for the genitourinary tract and has been isolated from virtually all genitourinary structures. Asymptomatic disease is common in both men and women, thus screening for disease is important. Various sociodemographic factors have been correlated with presence of T vaginalis, and may be used to predict infection. Diagnosis is usually made from wet mount microscopy and direct visualisation, which are insensitive. DNA amplification techniques perform with good sensitivity, but are not yet approved for diagnostic purposes. In areas where diagnostic methods are limited, management of trichomoniasis is usually as part of a clinical syndrome; vaginal discharge for women and urethral discharge for men. A single dose of metronidazole is effective in the majority of cases. Outside of the United States, other nitroimidazoles may be used and are as effective as metronidazole. Metronidazole resistance is an emerging problem, but its clinical importance is not yet clear. Concomitant treatment of sexual partners is recommended.     

性病门诊尿道/阴道炎患者阴道毛滴虫检测结果分析

目的研究性病门诊中阴道毛滴虫的检验方法,了解其感染状况。方法对383例尿道/阴道炎患者的尿道(阴道)分泌物同时采用湿片观察和培养法进行阴道毛滴虫(TV)的检测。结果在383例尿道/阴道炎患者中TV检出率为8.09%,其中男性尿道炎患者TV的检出率为零,明显低于女性阴道炎患者的21.68%(χ2=56.6,P<0.001),方法学比较显示女性TV检出率湿片检查法(18.18%)和培养法(21.68%)无明显差别(χ2=0.47,P>0.01)。结论性病门诊中TV的感染率占一定比例,均为女性感染;联合采用湿片检查法和培养法来检查阴道毛滴虫可提高检出率。     

Prevalence of Trichomonas vaginalis in men at high risk for sexually transmitted diseases

This study determined the prevalence of Trichomonas vaginalis in young men who were at high risk for sexually transmitted diseases; compared different diagnostic tests for trichomonads; and compared sexual behavior of men with positive and negative trichomonas test results. Men (85) aged 16-22 years inclusive, were recruited from a job-training program to participate in this study. Urethral specimens were obtained after prostatic massage for the isolation of Neisseria gonorrhoeae, Chlamydia trachomatis, and trichomonads. The diagnosis of trichomonas infection was made by urethral culture, urine sediment culture, direct examination of urine sediment, direct specimen test (DFA), and Papanicolaou (PAP) smear of urethral swab. Trichomonas vaginalis was seen in 58% of the men, gonorrhoea in 23.5%, chlamydia in 29%, pediculosis in 6%, and condyloma acuminata in 7%, respectively. There was no statistically significant difference in age of the participants, frequency of intercourse, and number of sexual partners in the last 3 months in men with positive and negative trichomonas test results. After controlling for gonorrhoea, pyuria was significantly associated with trichomonas-positive urine (P = .01). No single test was ideal for the diagnosis of trichomonas infection. Using a combination of urethral culture and urine sediment culture as the "gold standard," DFA was 60% sensitive and 73.0% specific. However, urine sediment culture along with DFA identified 94% of all men with positive trichomonas test results.