Unravelling the vaginal microbiome, impact on health and disease.

PURPOSE OF REVIEW: The vaginal microbiome has a fundamental role in supporting optimal vaginal, reproductive, and sexual health. Conversely, dysbiosis of the vaginal microbiome is linked to vaginal symptoms and adverse health outcomes. This review summarizes recent literature concerning the role of the vaginal microbiome in health and disease, with a focus on the most common vaginal dysbiosis, bacterial vaginosis. RECENT FINDINGS: Molecular studies have expanded our understanding of the composition of the vaginal microbiome. Lactic acid-producing lactobacilli are an important component of host defences against pathogens, whereas a paucity of lactobacilli is associated with adverse sequelae. Bacterial vaginosis is characterized by low levels of lactobacilli and increased levels of nonoptimal anaerobes; however, the exact cause remains unclear. Furthermore, despite decades of research, bacterial vaginosis recurrence rates following standard treatment are unacceptably high. Strategies to improve bacterial vaginosis cure and promote an optimal lactobacilli-dominated vaginal microbiome are being investigated. Importantly, historical and emerging evidence supports the sexual transmission of bacterial vaginosis, which opens exciting opportunities for novel treatments that incorporate partners. SUMMARY: A mechanistic and deeper understanding of the vaginal microbiome in health and disease is needed to inform ongoing development of therapeutics to improve bacterial vaginosis cure. Partner treatment holds promise for improving bacterial vaginosis cure.

Validation of self-reported human papillomavirus vaccination in young adult men who have sex with men.

The Victorian Government introduced a time-limited human papillomavirus (HPV) catch-up program for gay, bisexual, and other men who have sex with men (GBMSM) aged ≤ 26 years in 2017-2019. We conducted a retrospective observational study to examine the accuracy of the self-report of HPV vaccination status using computer-assisted self-interviewing versus their immunization history via electronic health records. We included GBMSM aged 23-30 years visiting the Melbourne Sexual Health Centre (MSHC) in 2020-2021 because they were age-eligible for the HPV catch-up program in Victoria, Australia. Individuals who were unsure about their vaccination status were categorized as 'unvaccinated'. Of the 1,786 eligible men, 1,665 men self-reported their HPV vaccination status: 48.8% (n = 812) vaccinated, 17.4% (n = 289) unvaccinated, and 33.9% (n = 564) unsure. Self-reported HPV vaccination had a sensitivity of 61.3% (95%CI: 58.3 to 64.2%; 661/1079), a specificity of 74.2% (95%CI: 70.5 to 77.7%; 435/586), a positive predictive value of 81.4% (95%CI: 78.6 to 84.0%; 661/812), a negative predictive value of 51.0% (95%CI: 47.6 to 54.4%; 435/853), and an accuracy of 52.6% (95%CI: 50.1 to 55.0%). Our results showed that only half of GBMSM know and report their HPV vaccination status correctly. Novel approaches such as digital vaccine passports may be useful for individuals to accurately report their vaccination status to guide accurate clinical decisions and management.

Cost-effectiveness of resistance-guided therapy for Mycoplasma genitalium in Australia.

The recommended first-line treatment for Mycoplasma genitalium infections is azithromycin. However, the prevalence of macrolide resistance for M. genitalium has increased to more than 50% worldwide. In 2013, Australia introduced a resistance-guided therapy (RGT) strategy to manage M. genitalium infections. This study assesses the cost-effectiveness of the RGT approach compared to no RGT (i.e., without macrolide resistance profile test) in women, men who have sex with men (MSM), and men who have sex with women (MSW) in Australia. We constructed dynamic transmission models of M. genitalium infections in women, MSM, and MSW in Australia, each with a population of 100,000. These models compared the costs and quality-adjusted life-years (QALYs) gained between RGT and no RGT scenarios from a healthcare perspective over ten years. All costs are reported in 2022 Australian dollars (Australian $). In our model, RGT is cost saving in women and MSM, with the incremental net monetary benefit of $1.3 million and $17.9 million, respectively. In MSW, the RGT approach is not cost-effective, with an incremental cost-effectiveness ratio of -$106.96 per QALY gained. RGT is cost saving compared to no RGT for M. genitalium infections in women and MSM, supporting its adoption as the national management strategy for these two population groups.

Systematic review and meta-analysis of the association between Mycoplasma genitalium and Pelvic inflammatory disease (PID).

BACKGROUND: Differences in opinion concerning the contribution of M. genitalium to pelvic inflammatory disease (PID) has resulted in inconsistencies across global testing and treatment guidelines. We conducted a systematic review and meta-analysis to determine the association between M. genitalium and PID and M. genitalium positivity within PID cases to provide a contemporary evidence base to inform clinical practice (PROSPERO registration: CRD42022382156). METHODS: PubMed, Embase, Medline and Web of Science were searched to Dec 1, 2023 for studies that assessed women for PID using established clinical criteria and used nucleic acid amplification tests to detect M. genitalium. We calculated summary estimates of the 1) association of M. genitalium with PID (pooled odds ratio [OR]) and 2) proportion of PID cases with M. genitalium detected (pooled M. genitalium positivity in PID), using random-effects meta-analyses, with 95% confidence intervals (CI). RESULTS: Nineteen studies were included: 10 estimated M. genitalium association with PID, and 19 estimated M. genitalium positivity in PID. M. genitalium infection was significantly associated with PID (pooled OR=1.67 [95%CI: 1.24-2.24]). The pooled positivity of M. genitalium in PID was 10.3% [95%CI: 5.63-15.99]. Subgroup and meta-regression analyses showed that M. genitalium positivity in PID was highest in the Americas, in studies conducted in both inpatient and outpatient clinic settings, and in populations at high risk of sexually transmitted infections. CONCLUSIONS: M. genitalium was associated with a 67% increase in odds of PID and was detected in about one in ten clinical diagnoses of PID. These data support testing women for M. genitalium at initial PID diagnosis.

Mycoplasma genitalium in pregnancy, including specific co-infections, is associated with lower birthweight: A prospective cohort study.

BACKGROUND: Mycoplasma genitalium infection in pregnancy is increasingly reported at similar frequencies to other sexually transmitted infections (STIs). Knowledge on its contribution to adverse pregnancy outcomes is very limited, especially relative to other STIs or bacterial vaginosis (BV). Whether M. genitalium influences birthweight remains unanswered. METHODS: Associations between birthweight and M. genitalium and other STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis) and BV in pregnancy were examined in 416 maternal-newborn pairs from a prospective cohort study in Papua New Guinea. FINDINGS: Compared to uninfected women, M. genitalium (-166.9 g, 95% confidence interval [CI]: -324.2 to -9.7 g, p = 0.038) and N. gonorrhoeae (-274.7 g, 95% CI: -561.9 to 12.5 g, p = 0.061) infections were associated with lower birthweight in an adjusted analysis. The association for C. trachomatis was less clear, and T. vaginalis and BV were not associated with lower birthweight. STI prevalence was high for M. genitalium (13.9%), N. gonorrhoeae (5.0%), and C. trachomatis (20.0%); co-infections were frequent. Larger effect sizes on birthweight occurred with co-infections of M. genitalium, N. gonorrhoeae, and/or C. trachomatis. CONCLUSION: M. genitalium is a potential contributor to lower birthweight, and co-infections appear to have a greater negative impact on birthweight. Trials examining the impact of early diagnosis and treatment of M. genitalium and other STIs in pregnancy and preconception are urgently needed. FUNDING: Funding was received from philanthropic grants, the National Health and Medical Research Council, and the Burnet Institute. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Prevalence of cefixime-resistant Neisseria gonorrhoeae in Melbourne, Australia, 2021-2022.

While ceftriaxone remains the first-line treatment for gonorrhoea, the US CDC recommended cefixime as a second-line treatment in 2021. We tested 1176 Neisseria gonorrhoeae isolates among clients attending the Melbourne Sexual Health Centre in 2021-2022. The prevalence of cefixime resistance was 6.3% (74/1176), azithromycin resistance was 4.9% (58/1176) and ceftriaxone resistance was 0% (0/1176). Cefixime resistance was the highest among women (16.4%, 10/61), followed by men-who-have-sex-with-women (6.4%, 7/109), and men-who-have-sex-with-men (5.8%, 57/982). The prevalence of cefixime-resistant N. gonorrhoeae exceeds the threshold of the 5% resistance level recommended by the World Health Organization; and thus, cefixime treatment would have limited benefits in Australia.

Economic evaluation alongside a clinical trial of near-to-patient testing for sexually transmitted infections.

BACKGROUND: Current clinical care for common bacterial STIs (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG)) involves empiric antimicrobial therapy when clients are symptomatic, or if asymptomatic, waiting for laboratory testing and recall if indicated. Near-to-patient testing (NPT) can improve pathogen-specific prescribing and reduce unnecessary or inappropriate antibiotic use in treating sexually transmitted infections (STI) by providing same-day delivery of results and treatment. METHODS: We compared the economic cost of NPT to current clinic practice for managing clients with suspected proctitis, non-gonococcal urethritis (NGU), or as an STI contact, from a health provider's perspective. With a microsimulation of 1000 clients, we calculated the cost per client tested and per STI- and pathogen- detected for each testing strategy. Sensitivity analyses were conducted to assess the robustness of the main outcomes. Costs are reported as Australian dollars (2023). RESULTS: In the standard care arm, cost per client tested for proctitis, NGU in men who have sex with men (MSM) and heterosexual men were the highest at $247.96 (95% Prediction Interval (PI): 246.77-249.15), $204.23 (95% PI: 202.70-205.75) and $195.01 (95% PI: 193.81-196.21) respectively. Comparatively, in the NPT arm, it costs $162.36 (95% PI: 161.43-163.28), $158.39 (95% PI: 157.62-159.15) and $149.17 (95% PI: 148.62-149.73), respectively. Using NPT resulted in cost savings of 34.52%, 22.45% and 23.51%, respectively. Among all the testing strategies, substantial difference in cost per client tested between the standard care arm and the NPT arm was observed for contacts of CT or NG, varying from 27.37% to 35.28%. CONCLUSION: We found that NPT is cost-saving compared with standard clinical care for individuals with STI symptoms and sexual contacts of CT, NG, and MG.

Vaginal anaerobes are associated with cervicitis: A case-control study.

OBJECTIVES: Cervicitis is associated with important reproductive sequelae. Primary causes include chlamydia and gonorrhoea, but a known sexually transmitted infection (STI) is not identified in >50% of cases (i.e. STI-negative cervicitis). Bacterial vaginosis (BV) and specific BV-associated bacteria have also been associated with cervicitis, but data are limited. We investigated the association between STI-negative cervicitis and vaginal microbiota composition. METHODS: This was a case-control sub-study of the OhMG study conducted at the Melbourne Sexual Health Centre. Cases were women with cervicitis who tested negative for STIs (STI-negative cervicitis, n = 64). Controls were STI-negative asymptomatic women attending for STI-screening (n = 128). The vaginal microbiota was characterised using 16S rRNA gene sequencing. Vaginal community state types were compared between cases and controls using logistic regression. Differential abundance analysis was performed to identify taxa associated with STI-negative cervicitis. RESULTS: STI-negative cervicitis cases were more likely than controls to have a Lactobacillus-deficient non-optimal microbiota (adjusted-odds-ratio 2.55, 95% CI 1.18-5.50). Compared to controls, cases had increased abundance of four BV-associated bacteria (Gardnerella, Fannyhessea vaginae, Prevotella bivia, Dialister micraerophilus) and decreased abundance of optimal lactobacilli. CONCLUSIONS: We report a positive association between non-optimal vaginal microbiota composition and STI-negative cervicitis. Specific anaerobic BV-associated bacteria may represent infectious causes of cervicitis.

Bacterial vaginosis after menopause: factors associated and women's experiences: a cross-sectional study of Australian postmenopausal women.

Background Bacterial vaginosis (BV) is the most common cause of vaginal discharge in reproductive age women; however, little is known about it after menopause. We aimed to learn more about BV in Australian postmenopausal women. Methods We conducted an online survey (July-September 2021). Participants were recruited via social media and professional networks and asked about demographic characteristics, sexual history and BV experiences. Outcomes of interest were the proportion who had heard of BV, had BV ever, or had BV after menopause. Factors associated with these outcomes were assessed using logistic regression. Results Of 906 participants, 83% were included in the analysis. Overall, 37.9% had heard of BV, 11.0% reported having a BV diagnosis ever, 6.3% reported having a BV diagnosis after menopause and 4.4% reported having a BV diagnosis only after menopause. Multivariable analysis found that among all women the odds of having a BV diagnosis after menopause were increased for those who had BV before menopause, had douched in the past 12months, or had a previous STI diagnosis. Among those in a sexual relationship, a BV diagnosis after menopause was associated with a BV diagnosis before menopause, or being in a sexual relationship of 5years or less in duration. About half who reported BV after menopause described recurrences, distress, and a detrimental effect on sexual relationships. Conclusions BV in postmenopausal women is associated with sexual activity, and impacts negatively on their lives. Research into BV should not be limited to reproductive age women.

Management of acute sexual assault presenting to a large Australian sexual health clinic in 2012-2021: a retrospective clinical audit.

Background The incidence of sexual assault continues to rise in Australia. This study aimed to describe the nature of assault, HIV/STI positivity, and its management at a sexual health clinic. Methods We performed a chart review of 516 sexual assault cases presenting to Melbourne Sexual Health Centre between 2012 and 2021, collecting data on victim demographics, details of assault, HIV/STI testing and positivity, police involvement, and offer of counselling. Results We included 516 cases: 124 males (24.0%); 384 females (74.4%); and eight transgender (1.6%) victims. The proportion of assault cases presenting to Melbourne Sexual Health Centre increased from 0.1% (37/37,070) in 2012 to 0.2% (56/36,514) in 2021 (P trend =0.006). HIV post-exposure prophylaxis was prescribed for 64.5% (80/124) of males and 12.5% (48/384) of females. Among victims, 69.4% (358/516) were tested for HIV and no one tested positive, while 71.9% (371/516) were tested for syphilis, with 1.6% (6/371) positive. Gonorrhoea and chlamydia were tested at the oropharynx (44.8% [231/516] vs 28.7% [148/516]), genitals (83.7% [432/516] vs 92.4% [477/516]) and anorectum (35.3% [182/516] vs 35.3% [182/516]). Positivity for gonorrhoea and chlamydia were: 2.6% (6/231) vs 2.0% (3/148) at oropharynx, 1.4% (6/432) vs 2.9% (14/477) at genitals, and 5.5% (10/182) vs 7.1% (13/182) at anorectum. According to clinical records, 25.2% (130/516) of victims sought police involvement, and 71.7% (370/516) were offered counselling. Conclusions Sexual assault was an uncommon presentation at Melbourne Sexual Health Centre, with diverse circumstances surrounding assault; however, clinical documentation varied, indicating a need for a standard primary care protocol for clients presenting with acute sexual assault.

Near-to-patient-testing to inform targeted antibiotic use for sexually transmitted infections in a public sexual health clinic: the NEPTUNE cohort study.

Background: Empiric treatment of sexually transmitted infections can cause unnecessary antibiotic use. We determined if near-to-patient-testing (NPT) for Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium (MG) improved antibiotic-use for a range of clinical presentations. Methods: Clients attending with non-gonococcal urethritis (NGU), proctitis, as STI-contacts, or for an MG-test-of-cure (MG-TOC) between March and December 2021 were recruited. Participants received near-to-patient-testing (NPT-group) for the three STIs using the GeneXpert® System (Cepheid), and concurrent routine-testing by transcription-mediated-amplification (TMA; Aptima, Hologic). Antibiotic-use among NGU or proctitis cases in the NPT-group was compared to clinic-controls undergoing routine-testing only. The proportion in the NPT-group who notified partners <24 hrs of their STI-specific result was calculated. Findings: Among 904 consults by 808 NPT-participants, ≥1 STI was detected in 63/252 (25.0%) with NGU, 22/51 (43.1%) with proctitis, and 167/527 (31.7%) STI-contacts. MG was detected among 35/157 (22.3%) MG-TOC consults. Among NGU and proctitis cases, fewer in the NPT-group received empiric treatment compared to clinic-controls (29.4% [95% CI: 24.3-34.9%] vs 83.8% [95% CI: 79.2-87.8%], p < 0.001), resulting in more NPT-group cases appropriately treated (STI-specific drug/no drug appropriately; 80.9% [95% CI: 76.0-85.1%] vs 33.0% [95% CI: 27.7-38.6%], p < 0.001) and fewer mistreated (incorrect drug/treated but pathogen-negative; 17.8% [13.7-22.6%] vs 61.4% [55.6-66.9%], p < 0.001). Of 167/264 in the NPT-group with an STI who responded regarding partner-notification, 95.2% notified all/some partners; 85.9% notified them <24 hrs of the STI-specific result. Interpretation: Near-to-patient-testing significantly improved antibiotic use and a high proportion of individuals rapidly notified partners of STI-specific results, highlighting the broad benefits of timely diagnostic strategies for STIs in clinical decision making and partner notification. Funding: ARC ITRP Hub-grant; NHMRC.

Increased syphilis testing and detection of late latent syphilis among women after switching from risk-based to opt-out testing strategy in an urban Australian sexual health clinic: a retrospective observational study.

Background: The Melbourne Sexual Health Centre (MSHC) implemented an opt-out syphilis test for women in December 2017. We aimed to examine the differences in syphilis testing uptake and confirmed syphilis cases among women after switching from risk-based to opt-out testing strategies. Methods: This was a retrospective study examining all women attending the MSHC for the first time in periods of risk-based testing (2015-2017) and opt-out testing (2018-2020). We calculated the proportion of women who tested for syphilis and the proportion of women with confirmed syphilis in each period. A chi-square test was performed to determine the differences in proportion between the risk-based testing and opt-out periods. Findings: A total of 27,481 women (i.e. 13,059 in the risk-based testing period and 14,422 in the opt-out period) were included in the final analysis, and the mean age was 26.8 years (standard deviation = 6.9). The proportion of women who were tested for syphilis at their first consultation increased from 52.8% (6890/13,059) in the risk-based testing period to 67.4% (9725/14,422) in the opt-out period (p < 0.0001). Syphilis positivity did not differ between the two periods (0.48% [33/6890] vs 0.71% [69/9725], p = 0.061) but late latent causes increased from 36.4% [12/33] to 60.9% [42/69] (p = 0.033). Interpretation: The opt-out testing strategy increased syphilis testing among women with increased detection of asymptomatic late latent syphilis. The opt-out syphilis testing strategy is beneficial in sexual health services. Health education and awareness may be required to improve syphilis testing uptake. Funding: National Health and Medical Research Council.