Incidence of syphilis seroconversion among HIV-infected persons in Asia: results from the TREAT Asia HIV Observational Database

Temporal Trends in Syphilis Incidence among Men with HIV in Busan, Korea, 2005-2022: A Retrospective Cohort Study

We aimed to assess the temporal trends of incident syphilis and its associated risk factors among men with HIV (Human Immunodeficiency Virus) in Korea during the COVID-19 pandemic. We conducted a retrospective cohort study of men with HIV attending an HIV clinic in Korea between 2005 and 2022. Of 767 men with HIV, 499 were included and contributed 3220 person-years (PY) of the observation period. Eighty-two patients were diagnosed with incident syphilis, with an overall incidence of 2.55/100 PY (95% confidence interval [CI] 20.56-31.53). The incidence of syphilis per 100 PY gradually decreased from 2.43 (0.79-7.42) in 2005-2007 to 1.85 (1.08-3.17) in 2014-2016; however, it increased to 3.0 (1.99-4.53) in 2017-2019, and further to 3.33 (2.26-4.89) in 2020-2022. A multivariate analysis identified young age (≤30 years versus >50, adjusted HR 6.27, 95% CI 2.38-16.56, p < 0.001), treponemal test positive at baseline (2.33, 1.48-3.67, p < 0.001), men who have sex with men (2.36, 1.34-4.16, p = 0.003), and history of incarceration (2.62, 1.21-5.67, p = 0.015) as risk factors for incident syphilis. Recently, syphilis incidence in men with HIV has increased in Korea, especially in young patients and at-risk groups, highlighting the need for enhanced regular screening and targeted behavioral interventions among these populations.

Prevalence, risk factors and treatment outcomes of syphilis among people living with human immunodeficiency virus at primary care clinics in Malaysia: A retrospective study

Introduction

Syphilis and human immunodeficiency virus (HIV) coinfection is a common clinical problem with a significant rising trend worldwide. In Malaysia, the burden of care is shared between hospitals and primary care clinics. This study aimed to determine the prevalence of syphilis among people living with HIV (PLHIV) at primary care clinics in Malaysia and assess its association with sociodemographic characteristics, risk factors and treatment outcomes.

Methods

This retrospective study included 750 PLHIV aged ≥18 years who attended primary care clinics in three different locations in Malaysia from 1 January 2017 to 31 December 2019. Data were obtained from the patients' clinical notes using a structured questionnaire evaluating the sociodemographic characteristics, history of sexual and lifestyle behaviours, diagnosis and management.

Results

The patients' age ranged from 18 to 78 years (mean=34.7, standard deviation=10.2). The prevalence of syphilis among the PLHIV at the three primary care clinics was 33.8% (n=254). Syphilis was significantly associated with gender (P=0.038) as well as sexual activity (P<0.001), substance use (P=0.038), history of chemsex (P=0.001) and history of sexually transmitted infections (STIs) (P<0.001) within the past 12 months. The majority of the PLHIV with syphilis received treatment at the primary care clinics (n=248, 97.3%), and up to 96.1% (n=245) had completed such treatment.

Conclusion

Syphilis is prevalent among PLHIV at primary care clinics, and most patients receive standard treatment. Therefore, primary care doctors must enhance their knowledge to effectively manage STIs, especially syphilis.

Prevalence of HIV and syphilis and their co-infection among men having sex with men in Asia: A systematic review and meta-analysis

Background

Studies found that the group of men who have sex with men (MSM) is at a very high level of risk of HIV and sexually transmitted infections (STIs) in Asian regions due to multiple reasons. Although the prevalence of HIV among general people in Asia is considered low, the prevalence of HIV and Syphilis among MSM in this region was found very high and usually, it goes unnoticed. This study aimed to inspect the prevalence of and trends in HIV, Syphilis, and their co-infection among MSM in Asia.

Methods

A systematic search was performed on January 5, 2021, in PubMed, Web of Science, and Google Scholar databases. To evaluate the heterogeneity, Q-tests, and I ² were used. To explore the publication bias, Eggers' test and funnel plot were used. The random-effect model and subgroup analysis were performed due to the significant heterogeneity.

Results

A total of 2872 articles were identified, and 66 articles were included in the final analysis. The overall prevalence of HIV and Syphilis among MSM was estimated considering 69 estimates from 66 studies whereas 19 estimates of co-infection were found in 17 studies. The pooled HIV prevalence was 8.48% (CI: 7.01-9.95) and the pooled Syphilis prevalence was 9.86% (CI: 8.30-11.41) with significant heterogeneity and publication bias. The pooled prevalence of HIV and Syphilis co-infection was 2.99% (CI: 1.70-4.27) with significant heterogeneity and no publication bias. The HIV, Syphilis, and HIV-Syphilis co-infection prevalence estimates exhibited an upward trend during 2002-2017.

Conclusions

HIV, Syphilis, and their co-infection are quite prevalent among MSM in the Asia-Pacific region. Integrated and intensified intervention strategies, HIV testing, and improved access to antiretroviral treatment as well as increased awareness are needed to reduce HIV, Syphilis, and their co-infection among the discussed vulnerable group.

Effects of syphilis infection among HIV-1-positive individuals on suppressive antiretroviral therapy

INTRODUCTION

Incident syphilis leads to changes in plasma HIV-1 RNA and CD4 + T-cell level in people with HIV (PWH) with viraemia. Its effect in PWH on suppressive antiretroviral therapy (ART) is less clear.

METHODS

PWH on suppressive ART (plasma HIV-1 RNA < 50copies/mL) followed at the Queen Elizabeth Hospital, Hong Kong, China were regularly screened for syphilis. Their plasma HIV-1 RNA, CD4 + and CD8 + T-cell, and total lymphocyte levels before syphilis, during syphilis, and after successful treatment were compared.

RESULTS

Between 2005 and 2020, 288 syphilis episodes from 180 individuals were identified; 287 episodes were related to male, with a median age of 41 at diagnosis; 221 (77%) were syphilis re-infection. The rates of plasma HIV-1 suppression were statistically unchanged across the time-points (97% pre-syphilis, 98% during syphilis, and 99% post-treatment). Total lymphocyte, CD4+ and CD8+ T-cell levels decreased during incident syphilis (p<0.01), and rebounded post-treatment (p<0.01). VDRL titre was associated with declines in CD4+ T-cell (p=0.045), CD8+ T-cell (p=0.004), and total lymphocyte levels (p=0.021). Pre-syphilis CD4/CD8 ratio was associated with increases in CD8+ T-cell (p=0.001) and total lymphocyte levels (p=0.046) during syphilis. Syphilis re-infection was associated with an increase in total lymphocyte level (p=0.037). In the multivariable analysis, only pre-syphilis CD4/CD8 ratio was independently associated with increases in CD8+ T-cell (p=0.014) and total lymphocyte levels (p=0.039) during syphilis.

CONCLUSIONS

Among virally-suppressed PWH, total lymphocyte, CD4+, and CD8+ T-cell levels declined during incident syphilis but rebounded post-treatment. The status of plasma HIV suppression was unaffected by syphilis.

Control of sexually transmitted infections and global elimination targets, South-East Asia Region

The World Health Organization (WHO) set targets for a 90% reduction in the incidence of syphilis and gonorrhoea between 2018 and 2030. We review trends in sexually transmitted infections in the WHO South-East Asia Region to assess the feasibility of reaching these targets. Myanmar, Sri Lanka and Thailand reported 90% or greater reductions in the incidence or prevalence of syphilis and/or gonorrhoea between 1975 and 2005. Evidence suggests that smaller, more recent reductions in trends in sexually transmitted infections in India have driven regional declines. In other countries, sexually transmitted infections remain high or are increasing or data are not reliable enough to measure change. Sri Lanka and Thailand have strong control programmes for sexually transmitted infections that ensure universal access to services for these infections and targeted interventions in key populations. India and Myanmar have implemented targeted control efforts on a large scale. Other countries of the region have prioritized control of human immunodeficiency virus, and limited resources are available for other sexually transmitted infections. At national and subnational levels, data show rapid declines in sexually transmitted infections when targeted promotion of condom use and sexually transmitted infection services are scaled up to reach large numbers of sex workers. In contrast, recent outbreaks of sexually transmitted infections in underserved populations of men who have sex with men have been linked to rising trends in sexually transmitted infections in the region. A renewed and focused response to sexually transmitted infections in the region is needed to meet global elimination targets.

Clinical and laboratory impact of concomitant syphilis infection during acute HIV

INTRODUCTION

Cognitive impairment has been reported in people living with HIV-1 (PLWH) with prior syphilis, while PLWH who present with incident syphilis have reduced blood CD4 T-lymphocyte and elevated HIV-1 RNA levels. However, the clinical, virological and neurocognitive effects of syphilis during acute HIV-1 (AHI) remain unknown.

METHODS

Pre-antiretroviral therapy laboratory outcomes and neurocognitive performance in a four-test battery in the SEARCH10/RV254 AHI cohort were compared according to syphilis status, determined by serum Treponema pallidum haemagglutination (TPHA), Venereal Disease Research Laboratory (VDRL) and syphilis treatment history. Impaired cognitive performance was defined as having z-scores ≤ -1 in at least two tests or ≤ -2 in at least one test.

RESULTS

Out of 595 AHI participants (97% male, median age of 26 years and estimated duration of HIV-1 infection of 19 days), 119 (20%) had history of syphilis (TPHA-positive), of whom 51 (9%) had untreated syphilis (TPHA-positive/VDRL-positive/without prior treatment). Compared with those without syphilis (TPHA-negative), individuals with untreated syphilis had higher CD8 T-lymphocyte levels but not higher plasma HIV-1 RNA or lower CD4 T-lymphocyte levels. Taking into account estimated duration of HIV-1 infection (P < 0.001), and later Fiebig stages (III-V) (P < 0.001), those with untreated syphilis had higher CD8 T-lymphocyte levels (P = 0.049). Individuals with any syphilis (TPHA-positive), but not untreated syphilis, had higher odds of impaired cognitive performance than those without (P = 0.002).

CONCLUSIONS

During AHI, individuals with any history of syphilis (TPHA-positive) had poorer cognitive performance than those without syphilis. However, syphilis was not associated with worsened HIV disease measures as described in chronic infection.

A novel peptide nucleic acid- and loop-mediated isothermal amplification assay for the detection of mutations in the 23S rRNA gene of Treponema pallidum

Introduction. Macrolides could be a potential alternative treatment for Treponema pallidum infections in patients; however, macrolide-resistant T. pallidum is spreading rapidly worldwide.Hypothesis/Gap Statement. There are presently no alternatives to serological tests for syphilis that can be used to evaluate therapeutic effects due to the fact that T. pallidum cannot be cultured in vitro.Aim. In this study, we constructed a method for rapidly identifying T. pallidum and confirming macrolide resistance by using loop-mediated isothermal amplification (LAMP) with peptide nucleic acids (PNAs).Methodology. A set of LAMP primers was designed to span nucleotide positions 2058 and 2059 in 23S rRNA. A PNA clamping probe was also designed to be complementary to the wild-type sequence (A2058/A2059) and positioned to interfere with both the annealing of the 3' end of the backward inner primer and the concomitant extension. Prior to the LAMP assay, swab samples from suspected syphilitic lesions were boiled for DNA extraction.Results. The assay had an equivalent detection limit of 1.0×10¹ copies/reaction and showed specificity against 38 pathogens. In the presence of a 4 µM PNA probe, LAMP amplified up to 1.0×101 copies/reaction using plasmids harbouring the complementary mutant sequences (A2058G or A2059G), whereas amplification was completely blocked for the wild-type sequence up to a concentration of 1.0×10³ copies/reaction. For the 66 PCR-positive clinical specimens, the overall detection rate via LAMP was 93.9 % (62/66). Amplification was successful for all 53 mutant samples and was incomplete for all nine WT samples by the PNA-mediated LAMP assays.Conclusion. We developed a PNA-mediated LAMP method that enabled us to rapidly identify T. pallidum and determine its macrolide susceptibility via a culture-independent protocol.

Syphilis seroprevalence and seroconversion among people newly diagnosed with HIV during the pre-antiretroviral therapy period in rural China

Syphilis has a high incidence among people living with HIV (PLHIV), which may be attributable to their similar sexual transmission route. A retrospective cohort study was conducted during the period 2009-2015 to investigate the syphilis seroprevalence and incidence of syphilis seroconversion among newly-diagnosed PLHIV in rural Yunnan, China. Recent HIV infection among PLHIV was identified by BED capture enzyme immunoassay. PLHIV were followed until they initiated antiretroviral therapy. Syphilis serology was conducted at baseline and each follow-up over the study period. Among 2162 participants, the syphilis seroprevalence at baseline was 2.7%, 95% confidence interval (CI) (2.4-3.1). Single and divorced (versus married) (aOR = 2.9, [1.1-7.4]; 5.9, [2.4-14.7], respectively), employed in the service industry (versus unemployed) (2.8, [1.4-5.6]), being diagnosed with HIV in hospitals (versus voluntary counselling and testing) (5.1, [2.0-12.9]), recent HIV infection (17.9, [8.5-37.9]) and inconsistent condom use in the previous three months (versus consistent condom use) (6.2, [2.8-13.4]) were associated with higher risk of syphilis infection at baseline. Participants contributed 1955.4 person-years (PYs) of follow-up, with a median follow-up period of 0.9 years (IQR: 0.5-1.9) and the incidence of syphilis seroconversion was 2.2 (95% CI 1.5-2.9) per 100 PYs. The syphilis seroprevalence at baseline (aHR 3.7, [1.8-7.9]), had a HIV-negative partner at baseline (3.9, [1.5-9.8]) and inconsistent condom use in the last three months at baseline (6.0, [1.4-25.4]) were associated with higher risk of syphilis seroconversion. Our findings indicate that the public health response should be escalated to minimise the spread of syphilis co-infection among PLHIV and reducing condomless sexual behaviours after HIV diagnosis.

Incidence of syphilis among HIV-infected men in Singapore, 2006-2017: temporal trends and associated risk factors

OBJECTIVE

There have been recent reports globally on substantial increase in syphilis diagnoses particularly among high-risk men. The aim of this study was to assess temporal trends of incident syphilis and associated risk factors among HIV-infected men in Singapore.

METHODS

We conducted retrospective cohort analysis using the clinical database maintained by the Clinical HIV Programme at the National Centre for Infectious Diseases, Singapore. HIV-infected men with a negative syphilis result at baseline who had undergone at least one subsequent test in 2006-2017 were included. Factors associated with incident syphilis were investigated using Cox proportional hazards regression analyses.

RESULTS

A total of 1069 HIV-infected men were tested for syphilis at least once following their negative baseline test during the 12-year period, and they contributed 4284 person-years of follow-up (PYFU). There were 266 cases of incident syphilis, giving an overall incidence of 6.21 per 100 PYFU (95% CI 5.49-7.00). The incidence of syphilis per 100 PYFU increased from 1.21 (95% CI 0.33 to 3.10) in 2010 to 26.04 (95% CI 19.97 to 33.40) in 2017. In the multivariable model, risk factors for syphilis seroconversion were: age 15-24 years at HIV diagnosis (adjusted HR (aHR) 1.64, 95% CI 1.05 to 2.56) versus ≥45 years, being Chinese (aHR 1.82, 95% CI 1.01 to 3.29) versus Indian and other minority ethnic groups, men having sex with men (MSM) (aHR 3.29, 95% CI 2.22 to 4.87) versus heterosexuals, and HIV diagnosis in later periods of 2009-2011 (aHR 1.96, 95% CI 1.41 to 2.74), 2012-2014 (aHR 3.96, 95% CI 2.68 to 5.83) and 2015-2017 (aHR 7.94, 95% CI 4.52 to 13.95) versus 2006-2008.

CONCLUSION

The annual incidence rate of syphilis in HIV-infected men was on the rise, and it was consistently higher among MSM than in heterosexual men. The findings supported regular screening for syphilis and enhanced behavioural interventions in Singapore.

Changes of sexual risk behaviors and sexual connections among HIV-positive men who have sex with men along their HIV care continuum

BACKGROUND

While HIV incidence among men who have sex with men (MSM) is increasing in Hong Kong, unprotected sex apparently remains prevalent among those infected but virally non-suppressed. Little is known about how sexual behaviours and sexual connections may change among MSM along their HIV care continuum.

METHODS

In this retrospective cross-sectional study, HIV-positive MSM attending the largest HIV specialist clinic in Hong Kong between October and December 2014 were invited to complete a self-administrated structured questionnaire. Their behavioural profile and partner sourcing patterns during the one-year period respectively (a) before HIV diagnosis, (b) after HIV diagnosis, (c) after initiation of antiretroviral treatment and (d) preceding the survey were examined.

RESULTS

Of 345 recruited MSM, 304 (88.1%) had treatment initiated and 272 (78.8%) had viral load suppressed. In the first year after HIV diagnosis, the proportion reporting inconsistent condom use dropped from 47.0% to 17.5% (p<0.05) and from 49.6% to 17.8% (p<0.01) for anal sex with main and casual partners respectively. Except for mobile applications, usage of most sex-networking venues decreased significantly after diagnosis. Inconsistent condom usage rate remained at around 20% after treatment initiation and viral load suppression, but the frequency of use of sex-networking venues further varied among virally suppressed MSM.

CONCLUSIONS

Most HIV-positive MSM had persistently low level of sexual risk behaviours along their care continuum and achieved viral load suppression, conferring a general reduction of secondary transmission risk in Hong Kong. To increase the effectiveness of Treatment as Prevention strategy, uptake of HIV testing for undiagnosed HIV-positive MSM shall be emphasised.

A field evaluation of a rapid dual immunoassay for human immunodeficiency virus and syphilis antibodies, Hanoi, Vietnam

The SD BIOLINE HIV/Syphilis Duo (SD BIOLINE DUO) rapid test is a dual rapid lateral flow immunoassay that detects antibodies to both human immunodeficiency virus (HIV) and Treponema pallidum (TP) 'syphilis' via fingerprick whole blood. We evaluated the field performance of the SD BIOLINE HIV/Syphilis Duo test among two populations in Hanoi, Vietnam - men who have sex with men (MSM) and pregnant women. We also surveyed factors that influence participants' willingness to test for HIV and syphilis. This test has the potential to increase HIV and syphilis screening in low-resource settings. Patients who received healthcare services at a sexual health clinic for MSM and a district antenatal care center in Hanoi, Vietnam were recruited for the study. Participants with HIV and syphilis were intentionally recruited for adequate test performance evaluation via convenience sampling. At each facility, venipuncture blood specimens were obtained for reference testing for HIV and TP using SD BIOLINE HIV 1/2 3.0 and TP particle agglutination, respectively. SD BIOLINE DUO was compared to the standard reference tests and sensitivity and specificity were calculated. We calculated 95% confidence interval (CI) using the exact binomial method. We used conjoint analysis to identify test attributes that are associated with participant likelihood to seek HIV and syphilis testing. Of 280 participants, 100 (35.7%) were MSM and 180 (64.3%) were pregnant women. Of MSM, 17 (17.0%) were HIV positive and 49 (49.0%) were TP seropositive. All women were negative for both HIV and syphilis antibodies. For HIV antibody testing, sensitivity and specificity were 100.0% (95% CI: 80.5-100.0%) and 100.0% (95% CI: 98.6-100.0%), respectively. For the syphilis antibody testing, sensitivity and specificity were 83.1% (95% CI: 71.0-91.6%) and 100.0% (95% CI: 98.3-100.0%), respectively. Potential for false positives, preference for one blood draw over two, and shorter wait time for testing results were the highest ranked attributes by participants according to their willingness to test. The SD BIOLINE HIV/Syphilis Duo rapid test demonstrated very good performance in this field setting and participants preferred attributes that aligned well with this test.

High subsequent and recurrent sexually transmitted infection prevalence among newly diagnosed HIV-positive Thai men who have sex with men and transgender women in the Test and Treat cohort

We determined subsequent and recurrent sexually transmitted infections (STIs) among men who have sex with men (MSM) and transgender women (TGW) in the Test and Treat cohort. Thai MSM and TGW adults with previously unknown HIV status were enrolled and tested for HIV. Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and syphilis were tested at baseline, month 12, and month 24 to identify subsequent STIs (any STIs diagnosed after baseline) and recurrent STIs (any subsequent STIs diagnosed among those with positive baseline STIs). Among 448 participants, 17.8% were HIV-positive, the prevalence of subsequent STIs and recurrent STIs was 42% (HIV-positive versus HIV-negative: 66.3% versus 36.7%, p < 0.001) and 62.3% (81% versus 52.5%, p < 0.001), respectively. Common subsequent STIs by anatomical site were rectal CT infection (21.7%), rectal NG infection (13.8%), pharyngeal NG infection (13.1%), and syphilis (11.9%). HIV-positive status was associated with both subsequent STIs (adjusted hazard ratio [aHR] 2.38; 95%CI 1.64-3.45, p < 0.001) and recurrent STIs (aHR 1.83; 95%CI 1.16-2.87, p = 0.01). The results show that newly diagnosed HIV-positive MSM and TGW were at increased risk of STIs despite being in the healthcare system. STI educational counseling is necessary to improve STI outcomes among MSM and TGW in both HIV prevention and treatment programs.

Syphilis Infection Differentially Regulates the Phenotype and Function of γδ T Cells in HIV-1-Infected Patients Depends on the HIV-1 Disease Stage

A rapidly escalating outbreak of syphilis infection has been affected men who have sex with men, particularly those with HIV-1 infection. γδ T cells are unconventional immune cells with two main subsets, Vδ1 T cells and Vδ2 T cells, which possess a combination of innate and adaptive immune features allowing them against HIV-1. However, whether syphilis infection affects the phenotype and function of γδ T cells in HIV-1-infected patients remains unclear, especially in acute HIV-1 infection (AHI). In this study, we enrolled 57 HIV-1-infected patients (24 with HIV-1 infection only and 33 coinfected with syphilis) from an acute HIV-1-infected cohort in Beijing (PRIMO). A comprehensive analysis of γδ T-cell phenotype and function was performed by flow cytometry. We found syphilis coinfection could reverse the imbalance of Vδ1/Vδ2 ratio in AHI. Syphilis infection results in decreased γδ T-cell activation in AHI, but increased γδ T-cell activation in chronic HIV-1 infection (CHI). Moreover, patients with CHI had larger numbers of IL-17-producing γδ T cells than those with AHI, regardless of syphilis status. Thus, syphilis affected the γδ T-cell immune response differently in patients depending on the stages of HIV-1 disease. In addition, the percentage of IL-17-producing γδ T cells was positively correlated with the percentage of neutrophils. These results suggest that the γδ T-cell/IL-17/neutrophil axis is involved in HIV-1 pathogenesis and disease progression. Taken together, our observations provide new insight into the roles of γδ T cells in immunopathogenesis of syphilis and HIV-1 coinfection, particularly during AHI, and our findings may be helpful for the prevention of syphilis and other sexually transmitted infections and highlight the great significance on the remedy of patients coinfected with HIV-1.