Facing increased sexually transmitted infection incidence in HIV preexposure prophylaxis cohorts: what are the underlying determinants and what can be done?

Frequent chlamydia and gonorrhoea but very infrequent syphilis among men who have sex with men using HIV pre-exposure prophylaxis in West Africa

OBJECTIVES

Although oral pre-exposure prophylaxis (PrEP) for HIV is being rolled out in West Africa, data on sexually transmitted infections (STIs) in PrEP users are scarce. We assessed the prevalence, incidence and determinants of bacterial STIs in men who have sex with men (MSM) taking PrEP in Burkina Faso, Côte d'Ivoire, Mali and Togo.

METHODS

A prospective cohort study among MSM initiating PrEP as part of a comprehensive HIV prevention package was conducted between 2017 and 2021 in community-based clinics in the four study countries. Molecular screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was performed at months 0, 6 and 12. Serological testing for syphilis was performed every 3 months over the first year of follow-up. Determinants of CT and/or NG incidence were identified using Poisson generalised linear mixed models.

RESULTS

A total of 598 participants with a median age of 24.7 years were included. Prevalence of CT and/or NG was 24.4% (95% CI 21.0 to 28.1), 22.4% (95% CI 18.4 to 26.8) and 29.0% (95% CI 24.2 to 34.1) at months 0, 6 and 12, respectively. The prevalence of syphilis ranged from 0.2% (95% CI 0.0 to 0.9) at month 0 to 0.8% (95% CI 0.2 to 2.4) at month 12. Ninety incident CT and/or NG infections occurred during a total follow-up time of 280.6 person-years (incidence rate 32.1 per 100 person-years, 95% CI 25.8 to 39.4). Three incident syphilis infections were detected during a total follow-up time of 459.7 person-years (incidence rate 0.7 per 100 person-years, 95% CI 0.1 to 1.9). CT and/or NG incidence was associated with condomless insertive anal sex (adjusted incidence rate ratio 1.96, 95% CI 1.04 to 3.71, p=0.038).

CONCLUSIONS

CT and NG were frequent but syphilis was very infrequent in MSM using HIV PrEP in West Africa. HIV programme managers should integrate STI services into PrEP programmes.

Sexual behaviour and STIs among MSM living with HIV in the PrEP era: the French ANRS PRIMO cohort study

INTRODUCTION

In a context of declining condom use and high sexually transmitted infection (STI) incidence, the diffusion of "treatment as prevention" (Tasp) and more recently pre-exposure prophylaxis (PrEP) may have changed the sexual behaviour of newly diagnosed men who have sex with men (MSM) with HIV.

METHODS

Six hundred and nine MSM were enrolled and followed annually between 2014 and 2021 in the ANRS PRIMO Cohort (ClinicalTrials.gov:NCT03148964) from the time of HIV seroconversion. We studied changes over calendar time in sexual behaviour before and after HIV diagnosis. Factors associated with inconsistent condom use (ICU) after HIV diagnosis, PrEP use by partner(s) and bacterial STI acquisition were studied in random-effects models.

RESULTS

In the 6 months preceding HIV diagnosis, the number of sexual partners decreased from a median of 10 (IQR: 4-19) in 2014 to 6 (3-11) in 2021. After HIV diagnosis, ICU increased from 57.1% (16/28) of visits in 2014 up to 84.2% (229/272) in 2020-2021. Up to 25% (63/229) of MSM with HIV in recent years reported the use of PrEP by their partner(s) as the reason for ICU; these MSM were less frequently in a stable relationship, had a higher number of sexual partners and higher education level than those who did not report the use of PrEP by their partner(s). STI incidence after HIV diagnosis increased between 2014 and 2016 and remained high afterwards. STI risk was no longer associated with PrEP use by partners after adjustment for the number of partners and calendar period. ICU, age below 35 years, not being in a stable relationship, higher number of sexual partners were independently associated with an increased risk of STI.

CONCLUSIONS

Implementation of TasP and more recently PrEP has led to major changes in the sexual behaviour of MSM with HIV. ICU has become overwhelmingly prevalent, PrEP use by the partner increasingly being the reported reason for ICU, behind TasP, which remains the main reason. Characteristics of MSM at the time of diagnosis of HIV have changed, with fewer number of sexual partners today than in 2014, which must lead to broaden the indications for PrEP prescription. STIs incidence remains high in MSM with HIV and requires improvements in screening and prevention methods such as pre- or post-exposition antibiotics or vaccines.

Detection of unreported usage of the antiretroviral drug lamivudine in two blood donors

BACKGROUND

Unreported HIV antiretroviral (ARV) drug usage by blood donors compromises the ability to detect evidence of HIV infection in blood screening tests and represents a risk for blood transfusion safety. Our objective was to determine the frequency of undeclared ARV drug use by blood donors with altered HIV markers.

STUDY DESIGN AND METHODS

This was a retrospective cross-sectional analysis of donations that were tested for HIV antibody (ab), antigen (ag), and RNA by chemiluminescent immunoassay and nucleic acid screening tests. Positive samples were retested and were subjected to ARV drug testing by high-performance liquid chromatography-tandem mass spectrometry.

RESULTS

Of 345,252 blood donations, 361 (0.1%) were positive on initial testing. Samples from 296 (81.9%) of these donations were available for further analysis. The presence of HIV ab/ag and/or RNA was confirmed in 83 (28.0%) of these samples. All 296 bloods were subjected to ARV testing. The ARV drug lamivudine, at 11.3 and 6.7 ng/mL, was detected in 2 of 83 (2.4%) donations that were HIV positive. Other drugs were not detected.

CONCLUSION

Unreported ARV usage was identified in two candidates for blood donation. More intensive efforts to educate donors about disclosure and to investigate the extent of this phenomenon in Brazil are needed.

The Discovery of Oropharyngeal Microbiota with Inhibitory Activity against Pathogenic Neisseria gonorrhoeae and Neisseria meningitidis: An In Vitro Study of Clinical Isolates

With increasing incidence of pathogenic Neisseria infections coupled with emerging resistance to antimicrobials, alternative approaches to limit the spread are sought. We investigated the inhibitory effect of oropharyngeal microbiota on the growth of N. gonorrhoeae and N. meningitidis and the impact of the essential oil-based mouthwash Listerine Cool Mint^® (Listerine). Oropharyngeal swabs from 64 men who have sex with men (n = 118) from a previous study (PReGo study) were analysed (ClinicalTrials.gov, NCT03881007). These included 64 baseline and 54 samples following three months of daily use of Listerine. Inhibition was confirmed by agar overlay assay, and inhibitory bacteria isolated using replica plating and identified using MALDI-TOF. The number of inhibitory isolates were compared before and after Listerine use. Thirty-one pharyngeal samples (26%) showed inhibitory activity against N. gonorrhoeae and/or N. meningitidis, and 62 inhibitory isolates were characterised. Fourteen species belonging to the genera Streptococci and Rothia were identified. More inhibitory isolates were observed following Listerine use compared to baseline, although this effect was not statistically significant (p = 0.073). This study isolated and identified inhibitory bacteria against pathogenic Neisseria spp. and established that daily Listerine use did not decrease their prevalence. These findings could provide a new approach for the prevention and treatment of pharyngeal Neisseria infections.

HIV pre-exposure prophylaxis and sexually transmitted infections: intersection and opportunity

Pre-exposure prophylaxis (PrEP) has revolutionized HIV prevention, but PrEP does not protect against other sexually transmitted infections (STIs). Rates of STIs are rising worldwide, with notably high incidences among PrEP-using men who have sex with men in high-income countries; in low-income and middle-income countries, data are sparse, but results from a limited number of studies among African women initiating and taking PrEP have shown high STI prevalence and incidence. Efforts aimed at markedly reducing HIV in populations worldwide include a major focus on increasing PrEP use, along with improving HIV testing and treatment in order to eliminate HIV transmission. Together, these efforts could augment continued expansion of the global STI epidemic, but they could alternatively create an opportunity to improve STI control, including the development of comprehensive sexual health programmes and research to develop new STI prevention strategies. The introduction of PrEP globally has been characterized by challenges and many successes, and its role as part of a range of robust strategies to reduce HIV infections is clear. Looking ahead, understanding rising rates of curable STIs and their relationship to HIV prevention, and considering the future directions for synergies in PrEP and STI prevention will be integral to improving sexual health.

Gonococcal bacterial load in PrEP users with Mycoplasma genitalium coinfection

OBJECTIVES

Gonococcal infections with a higher bacterial load may pose a higher risk of transmission. We assessed the association between gonococcal bacterial load and coinfection with Mycoplasma genitalium.

METHODS

From September 2015 until May 2018, 200 men and transgender women who have sex with men participated in an HIV pre-exposure prophylaxis (PrEP) demonstration trial in Antwerp, Belgium. They underwent 3-monthly 3-site (anus, urine, and pharynx) molecular testing for N. gonorrhoeae and C. trachomatis and M. genitalium, irrespective of symptoms. Gonococcal bacterial load was determined on remnant DNA extracts using an in-house quantitative PCR. Results were expressed as log₁₀ transformed copies/mL and analyzed with a linear regression model.

RESULTS

Gonococcal bacterial load could be determined for 82 (80.4%) of 102 anal, 17 (73.9%) of 23 urine, and 64 (90.1%) of 71 pharyngeal samples. M. genitalium was detected in five of these anal, two urine, and two pharyngeal samples and C. trachomatis was detected in 16 anal, one urine, and two pharyngeal samples. Gonococcal bacterial load was significantly higher in the presence of M. genitalium (difference 0.92 log copies/mL, 95% CI 0.16-1.67).

CONCLUSIONS

Gonococcal bacterial load was higher with M. genitalium coinfection. M. genitalium may thus be a cofactor in gonococcal transmission.

Educational level and risk of sexually transmitted infections among clients of Dutch sexual health centres

This study aimed to assess whether educational level is an independent determinant for sexually transmitted infections (STIs) among clients consulting Dutch sexual health centres (SHCs). With data from the National STI surveillance database (2015-2017), generalized estimating equations corrected for (sexual) risk factors were used to estimate associations between educational level and chlamydia and gonorrhoea among women (n = 146,020), heterosexual men (n = 82,882) and men who have sex with men (MSM) (n = 52,149) and syphilis and HIV among MSM. Compared to the highest educational level (bachelor/master), all lower educational levels were associated with gonorrhoea among women (adjusted odds ratio 1.40; 95% CI 1.18-1.66 for higher general/pre-university level to 3.57; 95% CI 2.66-4.81 for no education/elementary school level) and heterosexual men (respectively 1.36; 1.06-1.74 to 3.84; 2.89-5.09). Women with no education/elementary school level (1.37; 1.17-1.62) and heterosexual clients with (pre-)vocational secondary educational level were more likely to test positive for chlamydia (women: 1.43; 1.39-1.48 and heterosexual men: 1.31; 1.26-1.37) than clients with higher general/pre-university level or bachelor/master level. In MSM, (pre-)vocational secondary educational level was associated with chlamydia (1.16; 1.11-1.22), gonorrhoea (1.15; 1.10-1.21) and syphilis (1.18; 1.08-1.29), and both (pre-)vocational secondary educational level (1.48; 1.25-1.76) and no education/elementary school level (1.81; 1.09-3.00) were associated with HIV. Lower educational levels were independent determinants of STI in SHC clients. Sexual health centres could facilitate STI testing and care among lower educated people by prioritizing their access.

In Vitro Susceptibility of Treponema pallidum subsp. pallidum to Doxycycline

Doxycycline is regarded as an effective therapy for early syphilis, and there is increasing interest in using doxycycline for prophylaxis of this infection. However, the MIC of doxycycline for Treponema pallidum subsp. pallidum has not been reported previously. In this study, an in vitro culture system was utilized to determine that the MIC of doxycycline is 0.06 to 0.10 μg/ml for four strains of T. pallidum subsp. pallidum (Nichols, SS14, UW231B, and UW249B). The Nichols strain cultured in vitro with doxycycline was also tested for infectivity in rabbits, and the minimum bactericidal concentration (MBC) was found to be ≤0.1 μg/ml using this method. The low MIC and MBC values are consistent with the previously demonstrated clinical efficacy of doxycycline for the treatment of early syphilis. This study represents the first report of the in vitro susceptibility of T. pallidum to doxycycline, and the resulting information may be useful in the consideration of doxycycline for use in prevention of syphilis.

To What Extent Should We Rely on Antibiotics to Reduce High Gonococcal Prevalence? Historical Insights from Mass-Meningococcal Campaigns

In the absence of a vaccine, current antibiotic-dependent efforts to reduce the prevalence of Neisseria gonorrhoeae in high prevalence populations have been shown to result in extremely high levels of antibiotic consumption. No randomized controlled trials have been conducted to validate this strategy and an important concern of this approach is that it may induce antimicrobial resistance. To contribute to this debate, we assessed if mass treatment in the related species, Neisseria meningitidis, was associated with the emergence of antimicrobial resistance. To this end, we conducted a historical review of the effect of mass meningococcal treatment programmes on the prevalence of N. meningitidis and the emergence of antimicrobial resistance. We found evidence that mass treatment programmes were associated with the emergence of antimicrobial resistance.