Temporal associations with declining Trichomonas vaginalis diagnosis rates among women in the state of Victoria, Australia, 1947 to 2005

Positivity and Risk Factors for Trichomonas vaginalis Among Women Attending a Sexual Health Clinic in Melbourne, 2006 to 2019

BACKGROUND

Trichomonas vaginalis is not a notifiable disease in Australia in most states, resulting in limited Australian epidemiological studies. This study aimed to examine the positivity of T. vaginalis in women attending the Melbourne Sexual Health Centre (MSHC) and identify associated factors.

METHODS

All women 16 years or older who were tested for T. vaginalis at MSHC from 2006 to 2019 were included. The diagnostic method changed from culture to nucleic acid amplification test in August 2018. The annual positivity of T. vaginalis was calculated. Because of the data completeness, we performed a generalized estimating equations multivariable logistic regression using data from 2011 to 2019 to examine factors associated with T. vaginalis positivity.

RESULTS

From 2006 to 2019, 69,739 tests for T. vaginalis were conducted, and 294 tested positive (0.42%; 95% confidence interval [CI], 0.37%-0.47%). Approximately 60% of women tested reported symptoms. After adjusting for potential confounders including the change in diagnostic method, there was a 21% (95% CI, 12%-31%) annual increase in T. vaginalis positivity between 2011 and 2019. Women with concurrent syphilis had the highest odds of testing positive for T. vaginalis (adjusted odds ratio [aOR], 21.55; 95% CI, 6.96-66.78), followed by women who had injected drugs in the last 12 months (aOR, 6.99; 95% CI, 4.11-11.87), were 35 years or older (aOR, 3.47; 95% CI, 2.26-5.35), or had concurrent chlamydia (aOR, 1.77; 95% CI, 1.05-2.99).

CONCLUSIONS

The rising positivity of T. vaginalis at MSHC irrespective of change in diagnostic method suggests a concurrent community-wide rise in Melbourne. Given the rising positivity, testing informed by risk factors should be considered.

The clinical indications for testing women for Mycoplasma genitalium

BACKGROUND

While the contribution of Mycoplasma genitalium (MG) to symptoms in men is well described, less is known about its association with common genital symptoms in women. We aimed to determine the prevalence of MG and macrolide resistance, and its association with common genital symptoms in women attending a sexual health service, to inform indications for testing and clinical practice.

METHODS

We undertook a cross-sectional study of symptomatic and asymptomatic women attending Melbourne Sexual Health Centre (MSHC), between April 2017 and April 2019. Women were tested for MG and macrolide resistance, Chlamydia trachomatis (CT), Neisseria gonorrhoeae, Trichomonas vaginalis, bacterial vaginosis and vulvovaginal candidiasis. Women completed a questionnaire on symptoms, and symptomatic women underwent examination. The prevalence of MG (and macrolide resistance) and other genital infections was calculated with 95% CIs, and associations between these outcomes and specific genital symptoms were examined using logistic regression.

RESULTS

Of 1318 women, 83 (6%, 95% CI: 5% to 8%) had MG, of which 39 (48%, 95% CI: 36% to 59%) had macrolide-resistant MG; 103 (8%, 95% CI: 6% to 9%) women had CT. MG prevalence was similar in asymptomatic (10 of 195; 5%) and symptomatic (73 of 1108; 7%) women, p=0.506. MG was associated with mucopurulent cervicitis on examination (adjusted OR=4.38, 95% CI: 1.69 to 11.33, p=0.002), but was not associated with other specific genital symptoms or signs.

CONCLUSIONS

MG was as common as CT among women attending MSHC. MG was not associated with genital symptoms, but like CT, was significantly associated with cervicitis. These data provide evidence that routine testing for MG in women with common genital symptoms is not indicated. The presence of macrolide resistance in 48% of women supports use of resistance-guided therapy.

Increased diagnostic yield of routine multiplex PCR compared to clinician requested testing for detection of Trichomonas vaginalis

Trichomonas vaginalis (TV) infection is the leading cause of non-viral sexually transmitted infection (STI) globally and is endemic in rural and remote Australia. However, current accurate prevalence data for TV in urban Australia are scarce as TV is not a notifiable infection outside of the Northern Territory (NT). This study evaluated Australian guidelines for TV testing and determined TV prevalence among patients at a large urban public hospital in Melbourne, Australia. A retrospective analysis of genitourinary samples screened for STIs by multiplex polymerase chain reaction (MPCR) between May 2017 and April 2019 was performed. A total of 7155 results (5064 females) were included in the analysis. A prevalence for TV of 1.7% (n=123) was found, which was higher than Neisseria gonorrhoeae (1.4%, n=103) but less than Chlamydia trachomatis (5%, n=358). The highest rate of TV (3%) was found in females aged 30-44 years (n = 48). Routine MPCR improved TV detection almost six-fold compared with clinician request based testing. Current targeted testing guidelines for TV were inadequate for case finding in an urban setting, and clinical request among symptomatic patients was rare. MPCR testing provides a comprehensive testing strategy for curable STI, and removes the need for clinical suspicion of TV. Implementation of MPCR for STI screening can improve TV detection in populations not normally suspected to be at risk and therefore potentially reduce disease transmission or complications associated with undiagnosed infection.

Supplemental Trichomonas vaginalis testing is required to maintain control following a transition from Pap smear to HPV DNA testing for cervical screening: a mathematical modelling study

Objectives

Using mathematical modelling, we have previously shown that the prevalence of infection with Trichomonas vaginalis (TV) is likely to increase in the general population in Australia with the transition from Pap smear-based cervical screening to human papillomavirus (HPV) DNA testing. Here we use the existing model to estimate the level of supplemental testing required to maintain TV control.

Methods

A compartmental mathematical model describing the transmission of TV in the general heterosexual population in Australia was used to evaluate the impact of a range of screening scenarios on TV prevalence over time following the transition to HPV DNA testing for cervical screening. Scenarios considered were the inclusion of a TV test with the HPV test and the addition of TV testing to routine chlamydia testing conducted in primary care.

Results

Our modelling suggests that with sufficient coverage, inclusion of TV testing with routine chlamydia screening in general practice, TV prevalence can be reduced over time, but at the current reported coverage will gradually increase following the transition to HPV testing. Inclusion of TV testing with HPV testing in the cervical screening programme is preferable to no supplemental testing but is considerably less effective in controlling TV.

Conclusions

These findings support the inclusion of TV testing with routine chlamydia testing of young people.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Characteristics of acute nongonococcal urethritis in men differ by sexual preference

Nongonococcal urethritis (NGU) is a common clinical syndrome, but no etiological agent is identified in a significant proportion of cases. Whether the spectrum of pathogens differs between heterosexual men (MSW) and men who have sex with men (MSM) is largely unstudied but of considerable clinical relevance. A retrospective review was done using the electronic medical record database of Melbourne Sexual Health Centre, Australia. Cases were first presentations of symptomatic acute NGU with ≥ 5 polymorphonuclear leukocytes (PMNL)/high-powered field (HPF) on urethral Gram stain between January 2006 and December 2011. First-stream urine was tested for Chlamydia trachomatis and Mycoplasma genitalium by PCR. Demographic, laboratory, and behavioral characteristics of cases were examined by univariate and multivariable analyses. Of 1,295 first presentations of acute NGU, 401 (32%; 95% confidence interval [CI] of 29 to 34%) had C. trachomatis and 134 (11%; 95% CI of 9 to 13%) had M. genitalium detected. MSM with acute NGU were less likely to have C. trachomatis (adjusted odds ratio [AOR] = 0.4; 95% CI of 0.3 to 0.6) or M. genitalium (AOR = 0.5; 95% CI of 0.3 to 0.8) and more likely to have idiopathic NGU (AOR = 2.4; 95% CI of 1.8 to 3.3), to report 100% condom use for anal/vaginal sex (AOR = 3.6; 95% CI of 2.7 to 5.0), or to have engaged in sexual activities other than anal/vaginal sex (AOR = 8.0; 95% CI of 3.6 to 17.8). Even when C. trachomatis or M. genitalium was detected, MSM were more likely than MSW to report consistent condom use (OR = 4.7; 95% CI of 2.6 to 8.3). MSM with acute NGU are less likely to have the established bacterial sexually transmitted infections (STIs) and more likely to report protected anal sex or sexual activity other than anal sex prior to symptom onset than MSW. These data suggest that the etiologic spectrum of pathogens differs between MSM and MSW in acute NGU and that relatively low-risk practices are capable of inducing acute NGU.

Trichomonas vaginalis infection among women receiving gynaecological care at an Alabama HIV Clinic

OBJECTIVE

Trichomoniasis vaginalis is a risk factor for the acquisition and transmission of HIV. The objective of this study was to determine the prevalence of T vaginalis (using culture) among HIV-infected women receiving gynaecological care at an university HIV clinic in Alabama in addition to predictors of infection.

METHODS

Electronic medical record review of women presenting to the clinic for gynaecological care during 2006-2012 was performed. Demographic and sexual history data was abstracted in addition to absolute CD4 cell count, HIV-1 viral load and sexually transmitted infection (STI) (including T vaginalis) testing results. Analysis was conducted using Stata V.12.

RESULTS

T vaginalis was prevalent in 17.4% (83/478) of HIV-infected women; other STIs were less prevalent. Among these women, 384 presented for routine STI screening, of which 12% (46/384) were T vaginalis-infected. Younger age, African-American race, lifetime history of tobacco and drug abuse, lack of HIV therapy, HIV-1 viral load >400 copies/ml, and report of seeking gynaecological care for reasons other than routine STI screening (ie, having symptoms) were significant predictors of T vaginalis in univariate analysis. Age, African American race, and report of seeking gynaecological care for reasons other than routine STI screening remained associated with T vaginalis in multivariable analysis.

CONCLUSIONS

T vaginalis remains highly prevalent among HIV-infected women, a proportion of which may be asymptomatic. If left undiagnosed and untreated, these women may be more likely to transmit HIV. Increased emphasis on screening for high risk sexual behaviours, testing for T vaginalis, and risk reduction counselling is necessary for all HIV-infected women.

The prevalence of Trichomonas vaginalis detected by wet mount and polymerase chain reaction in Sydney women

Objectives Although Trichomonas vaginalis (TV) has a low profile in urban Australia, local data has estimated the prevalence in women to be 10 times higher when using polymerase chain reaction (PCR) versus wet mount microscopy (4.8% v. 0.4%). Our aim was to determine the prevalence of TV in Sydney women using both wet mount and PCR. Methods: A cross-sectional study was conducted of women requiring sexually transmissible infection screening at the Sydney Sexual Health Centre. Vaginal swabs were examined for TV using PCR and wet mount microscopy. Results: In total, 781 of 1263 eligible women were tested; 3 out of 781 tested positive by PCR and 1 out of 781 by wet mount, giving a prevalence of 0.38% (95% confidence interval (CI): 0.14–1.12%) and 0.13% (95% CI: 0.03–0.71%) respectively. There was not enough power to compare PCR and wet mount. Conclusions: The results of this analysis indicate that in our female urban population, TV is a very rare sexually transmissible infection,with 0.38% prevalence, and routine screening by PCR is not indicated.

Overview of molecular biological methods for the detection of pathogens causing sexually transmitted infections

We review here different state-of-the-art molecular methods currently used in the diagnosis of sexually transmitted infections.

Use of computerized medical records to determine the feasibility of testing for chlamydia without patients seeing a practitioner

The proportion of clinically important diagnoses in a low-risk, asymptomatic population who use a computer-assisted self-interview (CASI) to assess risk was needed to determine optimal health service delivery. Medical records were retrospectively analysed between July 2008 and June 2009 for risk characteristics and diagnoses. A total of 7733 new patients completed a CASI, of whom 1060 were asymptomatic heterosexuals. From this low-risk group, 26 diagnoses were made on the day of presentation, including 22 cases of genital warts (2.08% [95% confidence interval (CI) 1.22-2.93]), three cases of genital herpes (0.28% [95% CI 0.055-0.82]) and one case of unintended pregnancy (0.094% [95% CI 0.0061-0.52]). Additionally, there were 54 cases of chlamydia detected (5.09% [95% CI 3.77-6.42]). As chlamydia is effectively diagnosed and managed from self-collected samples, patient review is not always required. This study provides evidence for an express testing service for chlamydia to streamline the screening of low-risk, asymptomatic heterosexual patients as identified by CASI without the need to for a traditional face-to-face consultation.

Trichomonas vaginalis infection among women in a low prevalence setting

Objectives: Trichomonas vaginalis has become rare in Australian cities but remains endemic in some remote regions. We describe the prevalence and associations of infection among women attending an urban Australian sexual health clinic. Methods: A retrospective case control study was conducted with women diagnosed with T. vaginalis at Sydney Sexual Health Centre between January 1992 and December 2006. Proforma medical records for all women were reviewed to extract demographic, behavioural and diagnostic variables using a predefined data collection instrument. Results: Over the 15-year period, 123 cases of T. vaginalis were diagnosed, with a prevalence of 0.40%. Factors independently associated with infection were older age, vaginitis symptoms (adjusted odds ratio (AOR) 6.47; 95% confidence interval (CI), 3.29–12.7), sex with a partner from outside Australia (AOR 2.33; 95% CI, 1.18–4.62), a concurrent (AOR 3.65; 95% CI, 1.23–10.8) or past (AOR 2.67; 95% CI, 1.28–5.57) sexually transmissible infection, injecting drugs (AOR 7.27; 95% CI, 1.43–36.8), and never having had a Papanicolaou smear (AOR 7.22; 95% CI, 2.81–18.9). Conclusions: T. vaginalis infection was rare in women attending our urban clinic. Rarity, combined with an association with sex outside Australia, points to imported infections accounting for a large proportion of T. vaginalis infections in an urban population. The association with never having had cervical cancer screening, along with injecting drug use, likely reflects an increased prevalence in those with reduced access to health services or poor health seeking behaviours.

[Update on the epidemiology, diagnosis and treatment of sexually-transmitted infections]

In the last decade, cases of sexually-transmitted infections (STIs) have progressively increased in Europe. The reasons for this increase are unclear, but may involve changes in social behavior, migration and international travel, coupled with the emergence of risk groups that have not been taken into sufficient consideration to date. The routine use of molecular diagnostic techniques for many of these infections has solved many problems of sensitivity and the suitability of samples for microbiological diagnosis: non-invasive samples can be used, which has undoubtedly contributed to the increase in the number of cases. Moreover, molecular methods have also been introduced for antibiotic and antiviral susceptibility testing, as well as for molecular characterization of clinical isolates. All of these factors, together with the approval of the vaccine against the human papillomavirus, have changed the landscape of STIs across Europe.