Ongoing evolution of Chlamydia trachomatis lymphogranuloma venereum: exploring the genomic diversity of circulating strains

Lymphogranuloma venereum (LGV), the invasive infection of the sexually transmissible infection (STI) Chlamydia trachomatis , is caused by strains from the LGV biovar, most commonly represented by ompA-genotypes L2b and L2. We investigated the diversity in LGV samples across an international collection over seven years using typing and genome sequencing. LGV-positive samples (n=321) from eight countries collected between 2011 and 2017 (Spain n=97, Netherlands n=67, Switzerland n=64, Australia n=53, Sweden n=37, Hungary n=31, Czechia n=30, Slovenia n=10) were genotyped for pmpH and ompA variants. All were found to contain the 9 bp insertion in the pmpH gene, previously associated with ompA-genotype L2b. However, analysis of the ompA gene shows ompA-genotype L2b (n=83), ompA-genotype L2 (n=180) and several variants of these (n=52; 12 variant types), as well as other/mixed ompA-genotypes (n=6). To elucidate the genomic diversity, whole genome sequencing (WGS) was performed from selected samples using SureSelect target enrichment, resulting in 42 genomes, covering a diversity of ompA-genotypes and representing most of the countries sampled. A phylogeny of these data clearly shows that these ompA-genotypes derive from an ompA-genotype L2b ancestor, carrying up to eight SNPs per isolate. SNPs within ompA are overrepresented among genomic changes in these samples, each of which results in an amino acid change in the variable domains of OmpA (major outer membrane protein, MOMP). A reversion to ompA-genotype L2 with the L2b genomic backbone is commonly seen. The wide diversity of ompA-genotypes found in these recent LGV samples indicates that this gene is under immunological selection. Our results suggest that the ompA-genotype L2b genomic backbone is the dominant strain circulating and evolving particularly in men who have sex with men (MSM) populations.

PrEP your team! Clinician initiation of HIV pre-exposure prophylaxis discussion at sexually transmissible infection testing and diagnosis in gay and bisexual men

HIV pre-exposure prophylaxis (PrEP) is recommended for gay and bisexual men (GBM) with recent diagnosis of rectal chlamydia (CT), rectal gonorrhoea (NG) or infectious syphilis. A retrospective medical record audit was undertaken at Canberra Sexual Health Centre (CSHC) of all GBM who met this criterion in 2019 and were thus determined to be at higher risk of acquisition of human immunodeficiency virus (HIV). Pre-exposure prophylaxis was discussed and/or commenced in 85% of GBM at higher risk of HIV. Audit results and education were provided to the team with a post-interventional audit in 2020 showing significant improvement. This audit is easily replicated and may be applicable to other settings engaged in GBM care.

Seasonal variations in kissing and sexual activities among men who have sex with men in Melbourne, Australia: implications for seasonal sexually transmissible infection preventions and interventions

Background Previous studies have shown that there is a peak in sexually transmissible infection (STI) cases and sexual activities around summer, but there has been no study examining whether kissing also follows a similar seasonal pattern. The aim of this study was to examine the seasonal patterns of kissing and sex partners among gay, bisexual and other men who have sex with men (MSM). Methods: A short cross-sectional study was conducted among MSM attending the Melbourne Sexual Health Centre between March 2016 and February 2017. Participants were asked to report the number of kissing-only, sex-only and kissing-with-sex male partners in the last 3 months. The mean number of male partners was calculated and stratified by Australia’s seasons. The seasonal trend in the number of partners was assessed by negative binomial regression models. Results: In total, 4391 MSM were included in the analysis. The number of kissing-only and sex-only partners increased significantly from autumn to summer among MSM in Melbourne (Ptrend <0.001). MSM reported the highest number of male partners for kissing-only (mean: 4.91; 95% confidence intervals (CI): 4.78–5.04) and sex-only (mean: 1.91; 95% CI: 1.83–1.99) around summer compared with other seasons. However, the number of kissing-with-sex partners remained stable across seasons. Conclusions: The study data suggest that there is a peak in kissing-only and sex-only partners among MSM around summer and holiday seasons.

Perceptions of sexually transmissible infection pre-exposure prophylaxis: a qualitative study of high-risk gay and bisexual men in Sydney, New South Wales

Background Novel sexually transmissible infection (STI) prevention strategies are needed to combat increasing bacterial STI incidences alongside decreasing condom use among gay and bisexual men (GBM) in Australia. Sexually transmissible infection pre-exposure prophylaxis (STI-PrEP) using regular doxycycline is one such strategy that is the subject of ongoing research. However, a lack of qualitative data regarding the conceptualisation, perceived risks, perceived benefits and preferred dosing strategies of STI-PrEP may impede future research and implementation efforts. Methods: Semistructured in-depth interviews were conducted with 13 high-risk GBM residing in Sydney, Australia. Interviews were audio recorded, transcribed verbatim and then analysed thematically. Results: STI-PrEP was largely conceptualised using pre-existing knowledge of HIV-PrEP. The perceived benefits, including a reduced incidence of STIs, destigmatisation and a ‘peace of mind’, often outweighed the perceived risks, including side effects, antibiotic resistance and stigmatisation of consumers. A daily dosing regimen was preferred unanimously by participants when compared with event-driven or episodic strategies. Conclusions: Participants of this study were cautiously optimistic regarding the concept of STI-PrEP. The findings suggest that, in addition to examining the effectiveness of STI-PrEP, future implementation studies should also focus on concerns regarding side effects and monitoring antibiotic resistance, as well as considering the acceptability and potential for stigmatisation of STI-PrEP consumers.

Social and behavioural research prospects for sexually transmissible infection prevention in the era of advances in biomedical approaches

In the past two decades, major advances in biomedical intervention approaches to prevent HIV and many sexually transmissible infections (STIs) have shown great promise. However, challenges to prevention remain in the area of achieving population-level impact for biomedical prevention approaches. In this paper we address what social and behavioural research approaches can contribute beyond well-known behaviour change and counselling interventions. We organise work into five areas. Adherence and disinhibition research is primarily into individual-level constructs pertaining to maximising intervention effectiveness. Coverage research represents a population-level construct germane to maximising efficient prioritisation for prevention. Research covering social determinants, a second population-level construct, contributes to both prioritisation and effectiveness. Finally, disparities and social inequities need to be incorporated into prevention, given the pervasive and persistent disparities found in rates of HIV and STIs and in their antecedents.

Acceptability and feasibility of recruiting women to collect a self-administered vaginal swab at a pharmacy clinic for sexually transmissible infection screening

Willingness to self-collect vaginal swabs at a pharmacy clinic is of interest as a venue to increase sexually transmissible infections (STIs) screening for chlamydia, gonorrhoea and trichomonas. Women self-collected vaginal swabs at the pharmacy, completed questionnaires and received STI results within 2 h. Women with STIs were offered free treatment. A total of 313 of 777 (40.3%) women consented and prevalence for any STI was 3.9%. Questionnaires demonstrated acceptability for self-collection at the pharmacy, with 63% (95% CI 57.3–68) and 32.3% (95% CI 27.4–37.8) indicating they ‘strongly agreed’ or ‘agreed’ that they felt comfortable with pharmacy collection, respectively. Self-collected vaginal swabs for STI testing for women who were at a pharmacy were feasible and acceptable to women.

High levels of engagement with testing for HIV and sexually transmissible infection among gay Asian men in Sydney and Melbourne: an observational study

Background Gay and other men who have sex with men of Asian background (GAM) have been identified as a key population in efforts to eradicate HIV in New South Wales. The aims of the present study were to evaluate current levels of engagement with HIV and sexually transmissible infection (STI) testing services, assess knowledge of pre- and post-exposure prophylaxis and to identify factors associated with service engagement in this group. Methods: A survey of 604 GAM residing in Sydney and Melbourne was undertaken. Results: The data identified that a significant proportion of non-HIV-positive men (i.e. HIV-negative men and men whose HIV status was unknown) surveyed (n = 567; 93.9%) had engaged in frequent HIV testing and comprehensive STI testing in the 12 months prior to the survey (n = 180; 31.7%). There were significant differences (P < 0.05) in sexual practices at the bivariate level between those who reported frequent and comprehensive HIV/STI testing and those who did not. Those who tested regularly were substantially more sexually active, were more likely to have multiple partners (P = 0.001) and were more likely to engage in condomless anal intercourse with both casual (P < 0.001) and regular (P = 0.002) partners. Those who engaged with testing initiatives were more likely to discuss HIV status with both regular (P = 0.008) and casual (P < 0.001) partners, and identified more reasons to test than their counterparts (P < 0.001). The data also highlighted key service venues, with gay men most likely to have used public sexual health clinics (46.9%) as their most recent testing venue. Conclusions: The data demonstrate an association between high levels of male-to-male sexual activity and engagement in frequent and comprehensive HIV and STI testing. This likely derives from both self-perceived notions of risk and current reliance on established gay community organisations to convey information around testing. Increasing engagement with testing initiatives beyond GAM who self-identify as being at high HIV and STI risk will require the use of novel routes by which to disseminate this information.

Do we need to worry about sexually transmissible infections (STIs) in older women in Australia? An investigation of STI trends between 2000 and 2018

Background This study examined trends in chlamydia, gonorrhoea and syphilis diagnosis, and chlamydia testing and positivity, among older women in Australia between 2000 and 2018. Methods: Using national notifiable disease data and Medicare data, diagnosis rates were calculated for each sexually transmissible infection (STI), as well as testing and positivity rates for chlamydia. Data were compared between two older groups (55–64 and 65–74 years) and two younger groups (15–24 and 25–34 years). Poisson regression examined trends for 2000–18 and 2014–18 separately. Results: Rates for all STIs increased across all age groups and were highest in the two youngest age groups. From 2014 to 2018, chlamydia rates increased the most among those aged 55–64 years [incidence rate ratio (IRR) = 1.06; 95%CI: 1.02–1.10] and declined in those aged 15–24 years (IRR = 0.99; 95%CI: 0.99–0.99). Gonorrhoea rates increased the most among those aged 65–74 years (IRR = 1.47; 95%CI: 1.23–1.77) and least in those aged 15–24 years (IRR = 1.12; 95%CI: 1.10–1.13). Syphilis rates increased the most among those aged 55–64 years (IRR = 1.58; 95%CI: 1.25–1.99) and least in those aged 15–24 years (IRR = 1.29; 95%CI: 1.23–1.35). Chlamydia test positivity declined among younger women but remained stable in older women. Conclusions: In general, STIs are increasing among older women in Australia at a faster rate than among younger women. Although the greatest burden is among younger women, STIs need to be considered and monitored among older women.