Marcus Y. Chen

Rapid decline in presentations of genital warts after the implementation of a national quadrivalent human papillomavirus vaccination programme for young women.

Objective: This study aimed to determine if the Australian human papillomavirus (HPV) vaccination programme has had a population impact on presentations of genital warts. Methods: Retrospective study comparing the proportion of new clients with genital warts attending Melbourne Sexual Health Centre (MSHC) from January 2004 to December 2008. Australia provided free quadrivalent HPV vaccine to 12–18-year-old girls in a school-based programme from April 2007, and to women 26 years and younger through general practices from July 2007. Results: 36 055 new clients attended MSHC between 2004 and 2008 and genital warts were diagnosed in 3826 (10.6%; 95% CI 10.3 to 10.9). The proportion of women under 28 years with warts diagnosed decreased by 25.1% (95% CI 30.5% to 19.3%) per quarter in 2008. Comparing this to a negligible increase of 1.8% (95% CI 0.2% to 3.4%) per quarter from the start of 2004 to the end of 2007 also in women under 28 years generates strong evidence of a difference in these two trends (p<0.001). There was no evidence of a difference in trend for the quarterly proportions before and after the end of 2007 for any other subgroup, and on only one occasion was there strong evidence of a trend different to zero, for heterosexual men in 2008 in whom the average quarterly change was a decrease of 5% (95% CI 0.5% to 9.4%; p = 0.031). Conclusions: The data suggest that a rapid and marked reduction in the incidence of genital warts among vaccinated women may be achievable through an HPV vaccination programme targeting women, and supports some benefit being conferred to heterosexual men.

The near disappearance of genital warts in young women 4 years after commencing a national human papillomavirus (HPV) vaccination programme

Background Australia provided free quadrivalent human papillomavirus vaccines to 12–18-year-old girls and women aged ≤26 years from mid-2007 until the end of 2009. After this time, only girls aged 12–13 years had access to free vaccines. Methods Before and after the study, of the proportion of new patients attending Melbourne Sexual Health Centre from mid-2004 to mid-2011, diagnosed with genital warts (GW) by risk group. Results From July 2004 to June 2011, 52 454 new patients were seen at Melbourne Sexual Health Centre and 5021 (9.6%, 95% CI 9.3% to 9.8%) were diagnosed with GW. From July 2004 to June 2007, the proportions with GW either increased or did not change in all groups. Comparing the two 12-month periods of 2007/2008 and 2010/2011, GW declined in women under 21 years from 18.6% to 1.9% and in heterosexual men under 21 years from 22.9% to 2.9%. The ORs per year for diagnosis of GW adjusted for number of sexual partners from July 2007 until June 2011 in women and heterosexual men <21 years were 0.44 (95% CI 0.32 to 0.58) and 0.42 (95% CI 0.31 to 0.60), respectively. There was no significant change in GW in women ≥30 years (OR 0.97, 95% CI 0.84 to 1.12), heterosexual men ≥30 years (OR 0.97, 95% CI 0.89 to 1.06) or in homosexual men (OR 0.95, 95% CI 0.85 to 1.07). Conclusion The dramatic decline and near disappearance of GW in women and men under 21 years of age, 4 years after commencing this programme, suggest that the basic reproductive rate has fallen below one.

Persistence of Mycoplasma genitalium Following Azithromycin Therapy

Background To determine clinical outcomes and cure rates for M.genitalium genital infection in men and women following azithromycin 1 g. Methodology Patients attending Melbourne Sexual Health Centre between March 2005 and November 2007 with urethritis/epididymitis, cervicitis/pelvic inflammatory disease and sexual contacts of M.genitalium were tested for M.genitalium by polymerase chain reaction (PCR). M.genitalium-infection was treated with 1 g of azithromycin and a test-of-cure (toc) was performed one month post-azithromycin. Response to azithromycin, and response to moxifloxacin (400 mg daily for 10 days) in individuals with persistent infection post-azithromycin, was determined. Principal Findings Of 1538 males and 313 females tested, 161 males (11%) and 30 females (10%) were infected with M.genitalium. A toc was available on 131 (69%) infected individuals (median = 36 days [range 12-373]). Of 120 individuals prescribed azithromycin only pre-toc, M.genitalium was eradicated in 101 (84%, 95% confidence intervals [CI]: 77–90%) and persisted in 19 (16%, 95% CI: 10–23%). Eleven individuals with persistent infection (9%, 95% CI: 5–15%) had no risk of reinfection from untreated-partners, while eight (7%, 95% CI: 3–12%) may have been at risk of reinfection from doxycycline-treated or untreated-partners. Moxifloxacin was effective in eradicating persistent infection in all cases not responding to azithromycin. Patients with persistent-M.genitalium were more likely to experience persistent symptoms (91%), compared to patients in whom M.genitalium was eradicated (17%), p<0.0001. Conclusion Use of azithromycin 1 g in M.genitalium-infected patients was associated with unacceptable rates of persistent infection, which was eradicated with moxifloxacin. These findings highlight the importance of follow-up in M.genitalium-infected patients prescribed azithromycin, and the need to monitor for the development of resistance. Research to determine optimal first and second-line therapeutic agents for M.genitalium is needed.

Chlamydia trachomatis Incidence and Re-Infection among Young Women – Behavioural and Microbiological Characteristics

Background This study aimed to estimate rates of chlamydia incidence and re-infection and to investigate the dynamics of chlamydia organism load in prevalent, incident and re-infections among young Australian women. Methods 1,116 women aged 16 to 25 years were recruited from primary care clinics in Australia. Vaginal swabs were collected at 3 to 6 month intervals for chlamydia testing. Chlamydia organism load was measured by quantitative PCR. Results There were 47 incident cases of chlamydia diagnosed and 1,056.34 person years of follow up with a rate of 4.4 per 100 person years (95% CI: 3.3, 5.9). Incident infection was associated with being aged 16 to 20 years [RR = 3.7 (95%CI: 1.9, 7.1)], being employed [RR = 2.4 (95%CI: 1.1, 4.9)] and having two or more new sex partners [RR = 5.5 (95%CI: 2.6, 11.7)]. Recent antibiotic use was associated with a reduced incidence [RR:0.1 (95%CI: 0.0, 0.5)]. There were 14 re-infections with a rate of 22.3 per 100 person years (95%CI: 13.2, 37.6). The median time to re-infection was 4.6 months. Organism load was higher for prevalent than incident infections (p<0.01) and for prevalent than re-infections (p<0.01). Conclusions Chlamydia is common among young women and a high proportion of women are re-infected within a short period of time, highlighting the need for effective partner treatment and repeat testing. The difference in organism load between prevalent and incident infections suggests prevalent infection may be more important for ongoing transmission of chlamydia.

Macrolide resistance and azithromycin failure in a Mycoplasma genitalium-infected cohort, and response of azithromycin failures to alternative antibiotic regimens

BACKGROUND Our aim was to determine the efficacy of 1 g azithromycin and alternative antibiotic regimens in a prospective cohort of Mycoplasma genitalium-infected participants, and factors associated with azithromycin failure. METHODS Consecutive eligible M. genitalium-infected men and women attending the Melbourne Sexual Health Centre between July 2012 and June 2013 were treated with 1 g of azithromycin and retested by polymerase chain reaction (PCR) on days 14 and 28. Cure was defined as PCR negative on day 28. Cases failing azithromycin were treated with moxifloxacin, and those failing moxifloxacin were treated with pristinamycin. Pre- and posttreatment samples were assessed for macrolide resistance mutations (MRMs) by high-resolution melt analysis. Mycoplasma genitalium samples from cases failing moxifloxacin were sequenced for fluoroquinolone resistance mutations. Multivariable analysis was used to examine associations with azithromycin failure. RESULTS Of 155 participants treated with 1 g azithromycin, 95 (61% [95% confidence interval {CI}, 53%-69%]) were cured. Pretreatment MRM was detected in 56 (36% [95% CI, 28%-43%]) participants, and strongly associated with treatment failure (87% [95% CI, 76%-94%]; adjusted odds ratio, 47.0 [95% CI, 17.1-129.0]). All 11 participants who had MRM detected in posttreatment samples failed azithromycin. Moxifloxacin was effective in 53(88% [95% CI, 78%-94%]) of 60 cases failing azithromycin; all failures had gyrA and parC mutations detected in pretreatment samples. Six of 7 patients failing moxifloxacin treatment received pristinamycin, and all were PCR negative 28 days after pristinamycin treatment. CONCLUSIONS We report a high azithromycin failure rate (39%) in an M. genitalium-infected cohort in association with high levels of pretreatment macrolide resistance. Moxifloxacin failure occurred in 12% of patients who received moxifloxacin; all had pretreatment fluoroquinolone mutations detected. Pristinamycin was highly effective in treating macrolide- and quinolone-resistant strains.

What men who have sex with men think about the human papillomavirus vaccine.

This study aimed to ascertain the attitudes of men who have sex with men (MSM) to the human papillomavirus (HPV) vaccine and to determine the age at which MSM would be willing to ask for the HPV vaccine in relation to their age of sexual debut. Of 205 MSM attending the Melbourne Sexual Health Centre between December 2007 and January 2008, 200 (98%; median age 27 years) completed the study questionnaire. Only 30% were aware that there was a vaccine available for protection against infection with certain HPV types. When informed of the increased risk of anal cancer among MSM, 47% of MSM indicated that they would be willing to pay

Molecular approaches to enhance surveillance of gonococcal antimicrobial resistance

A450 for the vaccine course. A total of 93% indicated that they would be willing to disclose that they were MSM to a health professional in order to obtain the vaccine for free, but not until a median age of 20 years: 2 years after the median age of sexual debut (18 years) and after a median of 15 sexual partners. If the HPV vaccine is targeted to MSM, the challenge will be for MSM to be vaccinated before they acquire HPV infection.

Oral Human Papillomavirus in Men Having Sex with Men: Risk-Factors and Sampling

The best available data indicate that the world is heading towards a pandemic of extensively drug-resistant Neisseria gonorrhoeae. At the same time, clinical microbiology laboratories have moved away from using culture-based methods to diagnose gonorrhoea, thus undermining our ability to detect antimicrobial resistance (AMR) using current technologies. In this Opinion article, we discuss the problem of N. gonorrhoeae AMR, particularly emerging resistance to the cephalosporin ceftriaxone, outline current concerns about the surveillance of N. gonorrhoeae AMR and propose the use of molecular methods on a large scale to systematically enhance surveillance.

The prevalence of Chlamydia trachomatis infection in Australia: a systematic review and meta-analysis.

Background Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is becoming more common. We examined prevalence and risk factors for oral HPV among men who have sex with men (MSM) and compared sampling and transport methods. Methods In 2010, 500 MSM (249 HIV-positive) attending Melbourne Sexual Health Centre answered a questionnaire, swabbed their mouth and throat and collected a gargled oral rinse sample. Half the oral rinse was transported absorbed in a tampon (to enable postage). HPV was detected by polymerase chain reaction, and genotyped by Roche Linear Array®. Men with HPV 16 or 18 were retested after six months. Results Any HPV genotype was detected in 19% (95% confidence intervals (CI) 15–25%) of HIV-infected men and 7% (95% CI 4–11%) of HIV-negative men (p<0.001), and HPV 16 was detected in 4.4% (95% CI 2–8%) of HIV-infected men and 0.8% (0.1–2.8%) of HIV-negative men. Oral HPV was associated with: current smoking (adjusted odds ratio (aOR) 2.2 (95%CI: 1.2–3.9)), time since tooth-brushing (aOR per hour 0.87, 95%CI: 0.8–0.96) and number of lifetime tongue-kissing partners aOR 3.2 95%CI: (1.2–8.4) for 26–100 partners and 4.9 95%CI: (1.9–12.5) for>100 partners. Lifetime oral-penile sex partner numbers were significantly associated in a separate model: aOR 2.8(1.2–6.3) for 26–100 partners and 3.2(1.4–7.2) for>100 partners. HPV 16 and 18 persisted in 10 of 12 men after a median six months. Sensitivities of sampling methods compared to all methods combined were: oral rinse 97%, tampon-absorbed oral rinse 69%, swab 32%. Conclusions Oral HPV was associated with HIV infection, smoking, recent tooth-brushing, and more lifetime tongue-kissing and oral sex partners. The liquid oral rinse sample was more sensitive than a tampon-absorbed oral rinse or a self-collected swab.

Frequent screening for syphilis as part of HIV monitoring increases the detection of early asymptomatic syphilis among HIV-positive homosexual men.

BackgroundChlamydia trachomatis is a common sexually transmitted infection in Australia. This report aims to measure the burden of chlamydia infection by systematically reviewing reports on prevalence in Australian populations.MethodsElectronic databases and conference websites were searched from 1997–2011 using the terms ‘Chlamydia trachomatis’ OR ‘chlamydia’ AND ‘prevalence’ OR ‘epidemiology’ AND ‘Australia’. Reference lists were checked and researchers contacted for additional literature. Studies were categorised by setting and participants, and meta-analysis conducted to determine pooled prevalence estimates for each category.ResultsSeventy-six studies met the inclusion criteria for the review. There was a high level of heterogeneity between studies; however, there was a trend towards higher chlamydia prevalence in younger populations, Indigenous Australians, and those attending sexual health centres. In community or general practice settings, pooled prevalence for women <25 years in studies conducted post-2005 was 5.0% (95% CI: 3.1, 6.9; five studies), and for men <30 years over the entire review period was 3.9% (95% CI: 2.7, 5.1; six studies). For young Australians aged <25 years attending sexual health, family planning or youth clinics, estimated prevalence was 6.2% (95% CI: 5.1, 7.4; 10 studies) for women and 10.2% (95% CI: 9.5, 10.9; five studies) for men. Other key findings include pooled prevalence estimates of 22.1% (95% CI: 19.0, 25.3; three studies) for Indigenous women <25 years, 14.6% (95% CI: 11.5, 17.8; three studies) for Indigenous men <25 years, and 5.6% (95% CI: 4.8, 6.3; 11 studies) for rectal infection in men who have sex with men. Several studies failed to report basic demographic details such as sex and age, and were therefore excluded from the analysis.ConclusionsChlamydia trachomatis infections are a significant health burden in Australia; however, accurate estimation of chlamydia prevalence in Australian sub-populations is limited by heterogeneity within surveyed populations, and variations in sampling methodologies and data reporting. There is a need for more large, population-based studies and prospective cohort studies to compliment mandatory notification data.