Spatial and Temporal Epidemiology of Infectious Syphilis in Victoria, Australia, 2015-2018

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.

Treponema pallidum Detection at Asymptomatic Oral, Anal, and Vaginal Sites in Adults Reporting Sexual Contact with Persons with Syphilis

We investigated Treponema pallidum PCR positivity at mucosal sites (oral, anal, and vaginal sites) among adults who had sexual contact with a person with syphilis (syphilis contacts). All syphilis contacts had oral rinse and swab samples collected for testing. Men who have sex with men had anal swab and women had vaginal swab samples collected for testing, regardless of the presence of lesions. Of 407 persons tested, 42 (10%) had early syphilis diagnosed; of those, 19 (45%) tested positive by PCR from any anatomic site and had a positive serologic test. T. pallidum was positive from vaginal samples in 3 women, anal samples in 3 men, and oral cavity samples in 2 women and 3 men, without symptoms at those sites. Three women had no prior syphilis serologic test. T. pallidum detection at asymptomatic mucosal sites suggests early syphilis infections, particularly in cases that would conventionally be staged as latent syphilis of unknown duration.

Treponema pallidum PCR screening at mucosal sites of asymptomatic men who have sex with men taking HIV pre-exposure prophylaxis

Early detection and treatment of syphilis will reduce the infectious period and transmission. We aimed to determine whether screening men who have sex with men (MSM) taking HIV pre-exposure prophylaxis (PrEP) for syphilis using Treponema pallidum polymerase chain reaction (PCR) could detect syphilis before the appearance of syphilis antibodies in serology. MSM attending 3-monthly PrEP clinic visits in Melbourne, Australia, were screened with a PCR assay targeting the polA gene of T. pallidum from an anal swab and an oral rinse between November 2019 and March 2020. Participants were serologically screened for syphilis using chemiluminescence immunoassay. A total of 309 asymptomatic participants provided an anal swab and oral rinse sample for T. pallidum PCR screening. Two syphilis cases (0.6%) were detected: one man had a positive serology only; another man had T. pallidum detected by PCR from an anal swab and a positive serology. PCR positivity was 0.3% (n = 1) for anal swabs and 0% (n = 0) for oral rinse. In this study, T. pallidum PCR screening at routine PrEP clinic visits did not identify additional cases of early syphilis over serological screening performed at these visits. IMPORTANCE With the ongoing syphilis epidemic in men who have sex with men (MSM), we investigated the role of using Treponema pallidum polymerase chain reaction (PCR) testing at the oral cavity and anus in MSM taking pre-exposure prophylaxis for the early detection of syphilis. We evaluated whether the PCR tests from these mucosal sites can detect syphilis infection early, before the development of syphilis antibodies in serology. Our study found two syphilis cases among 309 MSM, and only one syphilis case had a positive anal PCR swab, although serology was positive. We conclude that additional PCR testing is likely to be expensive and would not be cost effective for individuals who regularly screen for syphilis. However, future studies with a larger sample size are required.

How Much Do Young Australians Know About Syphilis Compared With Chlamydia and Gonorrhea? Findings From an Online Survey

BACKGROUND

There is increased heterosexual transmission of syphilis in Australia, an infection with severe outcomes. Australian policy emphasizes increasing sexually transmissible infection knowledge/awareness. However, little is known about young Australians' perceptions and knowledge of syphilis.

METHODS

Our online sexual health survey was open May 2 to June 21, 2022, to 16- to 29-year-olds in Australia. We asked participants if they were aware of syphilis, their personal risk perception, and perceived severity of infection and compared with results for chlamydia/gonorrhea. Multivariable and multinomial logistic regressions were used to assess characteristics associated with outcomes. We measured sexually transmissible infection knowledge using 10 true/false statements (5 syphilis, 5 chlamydia/gonorrhea).

RESULTS

Among 2018 participants (69.1% women, 48.9% heterosexual), 91.3% had heard of syphilis (vs. 97.2% for chlamydia and 93.3% for gonorrhea). Older (25-29 years; adjusted odds ratio [aOR], 2.4; 95% confidence interval [CI], 1.4-4.4) and gay/lesbian (aOR, 2.8; 95% CI, 1.4-5.3) respondents were more likely to have heard of syphilis, as were those who were non-Aboriginal, sexually active, and with a school-based sex education. Syphilis knowledge was lower than chlamydia/gonorrhea knowledge ( P < 0.001). More than half (59.7%) perceived syphilis to have serious health impacts (vs. 36.4% for chlamydia and 42.3% for gonorrhea). Older respondents were more likely (25-29 years; aOR 2.1; 95% CI, 1.6-2.8), and gay/lesbian respondents less likely (aOR, 0.7; 95% CI, 0.6-1.0) to perceive syphilis to have serious health impacts. One-fifth of sexually active participants were unsure of their risk of syphilis.

CONCLUSIONS

Most young Australians are aware of syphilis, but few have comprehensive knowledge about the infection relative to chlamydia/gonorrhea. Considering increasing heterosexual transmission, syphilis health promotion campaigns should expand their focus.

The Reemergence of Syphilis Among Females of Reproductive Age and Congenital Syphilis in Victoria, Australia, 2010 to 2020: A Public Health Priority

BACKGROUND

Syphilis notifications in Victoria, Australia, have been increasing over the past decade, with an increase in infectious syphilis (syphilis of less than 2 years in duration) cases in females of reproductive age and an associated reemergence of congenital syphilis (CS). Before 2017, there had been 2 CS cases in the preceding 26 years. This study describes the epidemiology of infectious syphilis among females of reproductive age and CS in Victoria.

METHODS

Routine surveillance data provided by mandatory Victorian syphilis case notifications were extracted and grouped into a descriptive analysis of infectious syphilis and CS incidence data from 2010 to 2020.

RESULTS

In 2020, infectious syphilis notifications in Victoria were approximately 5 times more than 2010 (n = 289 in 2010 to n = 1440 in 2020), with a more than 7-fold rise among females (n = 25 in 2010 to n = 186 in 2020). Females made up 29% (n = 60 of 209) of Aboriginal and Torres Strait Islander notifications occurring between 2010 and 2020. Between 2017 and 2020, 67% of notifications in females (n = 456 of 678) were diagnosed in low-caseload clinics, at least 13% (n = 87 of 678) of all female notifications were known to be pregnant at diagnosis, and there were 9 CS notifications.

CONCLUSIONS

Cases of infectious syphilis in females of reproductive age and CS are on the rise in Victoria, necessitating sustained public health action. Increasing awareness among individuals and clinicians, and health system strengthening, particularly targeting primary care where most females are diagnosed before pregnancy, are required. Treating infections before or promptly during pregnancy and undertaking partner notification and treatment to reduce risk of reinfection are critical to reducing CS cases.

Changes in the Syphilis Rapid Plasma Reagin Titer Between Diagnosis and Treatment

BACKGROUND

We compared the rapid plasma reagin (RPR) titer on the day of initial presentation with that on the day of syphilis treatment to inform clinical practice as to whether a repeated RPR test should be recommended.

METHODS

We undertook a retrospective study between 1 March 2011 and 31 December 2020 at the Melbourne Sexual Health Centre in Australia among individuals who underwent syphilis serology on the day of initial presentation and the day of treatment, if the latter were within 14 days after initial presentation. We calculated the percentage of individuals with a ≥4-fold change in RPR titer, stratified by the time between initial presentation and treatment and by syphilis stage.

RESULTS

Among the 766 included syphilis cases, the median duration between initial presentation and treatment was 6 days (interquartile range, 5-7 days). Of these cases, 14.8% (n = 113) had a ≥4-fold increase or decrease during this interval. The number of cases with a ≥4-fold increase or decrease in RPR titer increased with increasing time between initial presentation and treatment, from 5.7% (n = 6) 1-3 days after initial presentation to 26.2% (n = 27) at 10-14 days (Ptrend < .001). There was no significant difference in the number of cases with a ≥4-fold increase or decrease in RPR titer between syphilis stages (P = .66).

CONCLUSIONS

Our data support the recommendation of repeating the RPR titer if the day of initial presentation and the day of treatment are different, even when treatment is within a few days after initial presentation.

Incidence and Risk Factors for Early Syphilis Among Men Who Have Sex With Men in Australia, 2013-2019: A Retrospective Cohort Study

Background

We aimed to examine the incidence of syphilis in men who have sex with men (MSM) and identify subgroups of MSM at a higher risk of syphilis infection.

Methods

We conducted a retrospective cohort study of MSM attending a sexual health clinic in Australia, during 2013-2019, who had at least 2 syphilis serological tests during the study period. The incidence of syphilis was expressed as per 100 person-years. A cox regression analysis was conducted to identify risk factors for syphilis.

Results

A total of 24 391 individual MSM (75 086 consultations) were included. A total of 1404 new syphilis cases were diagnosed with an incidence of 3.7/100 person-years (95% confidence interval, 3.5-3.9). Syphilis incidence was higher in MSM with human immunodeficiency virus ([HIV] 9.3/100 person-years) than in MSM taking HIV pre-exposure prophylaxis (PrEP) (6.9/100 person-years) or HIV-negative MSM not taking PrEP (2.2/100 person-years). Risk factors associated with high incidence of syphilis included the following: MSM with HIV (adjusted hazard ratio [aHR] 2.7), MSM taking HIV PrEP (aHR 2.1), past history of syphilis infection (aHR 2.4), injecting drug use (aHR 2.7), condomless anal sex (aHR 1.7), >4 sexual partners in the last 12 months (aHR 1.2), and concurrent sexually transmitted infection (chlamydia and gonorrhoea) (aHR 1.6).

Conclusions

The incidence of syphilis remains high among MSM, particularly in subgroups with associated risk factors for syphilis infections. These data highlight the need for biomedical and behavioral interventions to be targeted to subgroups of MSM at the highest risk of syphilis infection.

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.

Time to healthcare seeking following the onset of symptoms among men and women attending a sexual health clinic in Melbourne, Australia

BACKGROUND

Timely diagnosis and treatment of sexually transmitted infections (STIs) underpin their control by reducing the duration of infectiousness. There are currently limited data exploring healthcare seeking among individuals with STI symptoms.

METHODS

We analyzed data on individuals reporting STI symptoms at the Melbourne Sexual Health Centre (MSHC) between August 2017 and December 2020. We calculated the time between symptom onset and clinic attendance by risk group for 13 STI diagnoses. We performed univariable and multivariable logistic regression analyses to explore factors associated with delayed healthcare seeking (greater than 7 days).

RESULTS

Among 7,032 symptomatic clinic attendances, the shortest time to healthcare seeking was among individuals diagnosed with gonococcal urethritis (median 3 days), and the longest was among individuals diagnosed with genital warts (median 60 days). Individuals diagnosed with gonococcal urethritis sought care earlier than individuals diagnosed with non-gonococcal urethritis (median 3 vs. 6 days, p < 0.001), and individuals diagnosed with genital herpes sought care earlier than individuals diagnosed with primary syphilis (median 4 vs. 14 days, p < 0.001). Men who have sex with men, and men taking human immunodeficiency virus pre-exposure prophylaxis (PrEP), were least likely to delay healthcare seeking. Both men and women who delayed healthcare seeking were more likely to live further from the clinic than those who did not delay their presentation [p trend < 0.001 (men) and p trend = 0.049 (women)].

CONCLUSION

Improved local access to healthcare alongside targeted strategies to encourage early healthcare seeking among groups at increased likelihood of delay may reduce STI-associated morbidity and transmission.

Adherence to weekly anal self-examination among men who have sex with men for detection of anal syphilis

Background

Men who have sex with men (MSM) practicing exclusively receptive anal sex are more likely to present with secondary than primary syphilis, implying primary anorectal lesions may be missed. If men could detect anorectal lesions by regular anal self-examination, the duration of infectiousness could be reduced. This study aimed to examine adherence to weekly anal self-examination.

Method

We conducted a longitudinal feasibility study examining the adherence to weekly anal self-examinations among MSM attending a sexual health clinic in Melbourne, Australia between December 2020 and June 2021. Adherence to weekly anal self-examinations over 12 weeks was assessed from a logbook and 4-weekly surveys. Participants who identified abnormalities in their anus were recommended to seek medical review.

Results

Of the 30 men who completed the study, anal self-examination was performed at least weekly for 308 of 360 person-weeks (86% of the weeks, 95% CI: 82–89). The mean adherence was 3.6 (95% CI: 3.3–3.9) examinations per 4-weeks per person in Weeks 1–4, 3.5 (95% CI: 3.1–3.8) in Weeks 5–8 and 3.3 (95% CI: 2.9–3.7) in Weeks 9–12 (P_trend = 0.06). Six men (20%, 6/30) were seen for medical review after they identified abnormalities, whilst eight men (27%, 8/30) reported abnormalities, but did not seek medical review. No participants were diagnosed with syphilis during the study period.

Conclusion

We conclude that men adhered well to weekly anal self-examination. Therefore, it is feasible to trial this as a routine practice among MSM. Future studies should investigate possible reductions in adherence over time and ways to increase medical review for abnormalities that men find.

A cross-sectional survey on attitudes of men who have sex with men towards anal self-examination for detection of anal syphilis

Studies suggest men who have sex with men (MSM) practising receptive anal sex are more likely to present with secondary syphilis, implying primary anorectal lesions are likely to be missed. If men could detect anorectal lesions in the primary stage by regular anal self-examination (ASE), transmission could be reduced by early diagnosis and treatment. We aimed to explore the attitudes of MSM on performing ASE to detect primary anorectal syphilis. An online anonymous cross-sectional survey among MSM over 18 years of age living in Australia, was conducted between July and November 2020 and recruitment was from a sexual health clinic and social media. A total of 568 MSM completed the survey (median age: 34 [IQR 27–45]): 32% (183) had previously performed ASE. Among 66% (374) who had never performed ASE, 68% (250) would consider performing ASE in the future with a preferred median frequency of 2 times per 4 weeks (IQR 1–4), whilst men who were already performing ASE were performing it at median 1 per 4 weeks (IQR 0.2–3). Almost two-thirds of MSM who had never performed ASE were willing to adopt ASE practice in the future. Studies are required to determine the effectiveness of ASE for syphilis detection.

Preferences of men who have sex with men for performing anal self-examination for the detection of anal syphilis in Australia: A discrete choice experiment

BACKGROUND

Regular anal self-examination could potentially reduce syphilis transmission by detecting anal syphilis earlier among men who have sex with men (MSM). This study aimed to examine the preferences of MSM on performing anal self-examination to detect anal syphilis.

METHODS

An online survey with a discrete choice experiment (DCE) was distributed to MSM attending a sexual health clinic and through social media in Australia between June and November 2020. The DCE examined the preferred attributes of anal self-examination that would encourage MSM to perform anal self-examination. Data were analysed using a random parameters logit (RPL) model.

FINDINGS

The median age of 557 MSM who completed the survey was 35 (inter quartile range, 27-45). The choice to perform anal self-examination was most influenced by two attributes: the accuracy of anal self-examination to diagnose anal syphilis, and the frequency of anal self-examination, followed by the type of instruction materials to perform anal self-examination, waiting time for medical review, and type of support received if abnormalities were found. Using the most preferred attributes, 98% of people would conduct anal self-examination compared with 35% when the least preferred anal self-examination attributes were offered.

INTERPRETATION

If anal self-examination were recommended for anal syphilis screening, it will be important to consider preferences of MSM: men were more likely to undertake anal self-examination if the frequency was once a month and there was higher accuracy of detecting anal syphilis.

FUNDING

Australian National Health And Medical Research Council.

Improving Access to Sexual Health Services in General Practice Using a Hub-and-Spoke Model: A Mixed-Methods Evaluation

Improving access to sexual health services is critical in light of rising sexually transmitted infections (STIs). We evaluated a hub-and-spoke model for improving access to sexual health services in three general practices in Victoria, Australia. The primary outcome was the impact on HIV and STI (chlamydia, gonorrhoea, syphilis) testing. Segmented linear regression analysis was conducted to examine the trends in the total HIV/STI tests pre- (from January 2019 to June 2020) and post-implementation (from July 2020 to July 2021). We evaluated the feasibility and acceptability of integrating this model into the general practices using semi-structured individual interviews. There was a statistically significant rise in testing for HIV and STIs in all general practices: post-implementation, there was an increase of an average of 11.2 chlamydia tests per month (p = 0.026), 10.5 gonorrhoea tests per month (p = 0.001), 4.3 syphilis tests per month (p = 0.010), and 5.6 HIV tests per month (p = 0.010). Participants reported increases in knowledge level and confidence in offering STI testing and managing a greater variety of sexual health cases. This study demonstrates the feasibility of implementing a hub-and-spoke model to enable GPs to deliver sexual health care with support from a sexual health specialist service.

Exploring the attitudes of men who have sex with men on anal self-examination for early detection of primary anorectal syphilis: a qualitative study

BACKGROUND

Studies show men who have sex with men (MSM) practising receptive anal sex are more likely to present with secondary syphilis, suggesting anorectal primary lesions are being missed. Regular anal self-examination might be able to detect anorectal syphilis lesions, hence potentially reducing transmission. This study aimed to explore the attitudes of MSM on performing anal self-examination to detect primary syphilis.

METHODS

In this qualitative study, 20 MSM over 18 years of age were purposively sampled from a sexual health clinic to participate in semi-structured interviews. Interviews were recorded, transcribed verbatim and data analysed thematically.

RESULTS

Four major themes and 12 sub-themes were generated from the study: (1) reasons for performing anal self-examination, (2) preferred educational resources for anal self-examination, (3) attitudes towards partner anal examination, and (4) acceptability of anal self-examination. Most participants had performed some form of anal self-examination in the past, and, just over half performed regularly for mostly health-related concerns. Most participants who infrequently or never performed anal self-examination were agreeable to perform regularly if it was recommended by health professionals with appropriate guidance. Participants preferred education on anal self-examination from health professionals and trusted online learning resources.

CONCLUSION

Our study showed MSM were agreeable to anal self-examination however would like to receive education and training to gain more confidence in conducting anal self-examination as a screening tool. Further studies are required to explore the adherence and acceptability of anal self-examination for syphilis prior to studies examining efficacy. The study provides foundation for any future policy aiming at utilising anal self-examination as a screening tool for syphilis among MSM.