Toward a Set of Criteria to Decide Which STIs to Screen for in PrEP Cohorts

Management of asymptomatic sexually transmitted infections in Europe: towards a differentiated, evidence-based approach

Most sexually transmitted infections (STIs) can be accurately diagnosed and treated during asymptomatic carriage. Widespread screening for these STIs is therefore assumed to be an effective way to reduce their prevalence and associated disease. In this review, we provide evidence that this is the case for HIV and syphilis. However, for other STIs such as Neisseria gonorrhoeae and Chlamydia trachomatis, our review reveals that the evidence that screening reduces infection prevalence and associated disease is weak. There is also growing evidence of harms from screening that might outweigh any benefits. The harms include the increased consumption of antimicrobials that follows frequent screening and increased detection of asymptomatic STIs in key populations, such as men who have sex with men taking HIV pre-exposure prophylaxis, and associated risk of antimicrobial resistance in target and non-target organisms. There may also be psycho-social harm associated with an STI diagnosis. We conclude that in the absence of symptoms, in high STI prevalence populations frequent STI screening should be limited to HIV and syphilis.

Very High Incidence of Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum among Low-Risk MSM in an Outpatient Clinic in Wroclaw, Poland in 2019-2020

BACKGROUND

The rise in sexually transmitted infections and chemsex has led to syndemy with HIV, partly due to common routes of transmission and clustered transmissions. Despite this, barriers to STI care and PrEP still remain. We sought to determine whether MSM at low risk for HIV infection were also at low risk for other STIs.

METHODS

The study group was tested for HIV, HCV, and Treponema pallidum, as well as had urethral, rectal, and oropharyngeal smears performed for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) six months apart. The control group was tested once to define the background incidence.

RESULTS

Treponema pallidum, CT, and NG prevalence was very high at both time points and was similar to the control group. CT was especially common in the control group (20.58%) and the study group at the rectal site at the second time point (9.37%). NG dominated the oropharyngeal site (15.87%), with urethral site sparing. NG infection was associated with an increased number of partners, not condom use (OR, 1.082 [95% CI; 1.009-1.171]). Risk behavior did not change between the time points. Treponema pallidum, CT, and NG incidence was exceptionally high (12.5/100PY, 25.39/100PY, 34.92/100PY, respectively; pooled 87.5/100PY) and was comparable to other studies of high-risk MSM.

CONCLUSIONS

Despite a lower risk for HIV acquisition, the study group was at a very high risk for other STIs, and this risk remained high throughout the study. Patients and medical professionals should be aware of syphilis, gonorrhea, and chlamydiosis transmission risks, and screening should be performed accordingly. Prophylactic programs need to be updated to specifically include lower-risk individuals.

Recent insights suggest the need for the STI field to embrace a more eco-social conceptual framework: A viewpoint

A large number of countries are being confronted with twin epidemics of increasing STI incidence and antimicrobial resistance (AMR). This has led to calls to intensify STI screening of high STI prevalence populations. The available evidence suggests that this will have little impact on STI prevalence but a significant deleterious effect on AMR. We suggest that this call to intensify STI screening is one of the several errors that stem from the way that the STI-field has been dominated by a biomedical individualistic conceptual framework. This framework views STIs as obligate pathogens that can and should be eradicated by intensive seek-and-destroy activities. We evaluate five types of evidence that suggest that a multi-level, socio-ecological framework would provide a more accurate portrayal of the important determinants of STI prevalence and AMR spread. By incorporating concepts such as limiting STI screening to scenarios with clear evidence of net-benefit and considering 'antimicrobial footprint' thresholds, this framework would be more likely to result in a better balance between targeting STI prevalence whilst minimizing the risk of AMR emerging.

To Pool or Not to Pool Samples for Sexually Transmitted Infections Detection in Men Who Have Sex With Men? An Evaluation of a New Pooling Method Using the GeneXpert Instrument in West Africa

BACKGROUND

Men who have sex with men (MSM) using preexposure prophylaxis (PrEP) are at risk for sexually transmitted infections (STIs). Therefore, PrEP services should include regular screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) at urethra, anorectum, and pharynx. However, financial and logistic challenges arise in low-resource settings. We assessed a new STI sample pooling method using the GeneXpert instrument among MSM initiating PrEP in West Africa.

METHODS

Urine, anorectal, and pharyngeal samples were pooled per individual for analysis. In case of an invalid result only (strategy 1) or a positive result of the pool (strategy 2), samples were analyzed individually to identify the infection's biological location. The results of 2 different pooling strategies were compared against the individual results obtained by a criterion standard.

RESULTS

We found a prevalence of 14.5% for chlamydia and 11.5% for gonorrhea, with a predominance of infections being extragenital (77.6%). The majority of infections were asymptomatic (88.2%). The pooling strategy 1, had a sensitivity, specificity and agreement for CT of 95.4%, 98.7%, and 0.93, respectively; and 92.3%, 99.2%, and 0.93 for pooling strategy 2. For NG, these figures were 88.9%, 97.7%, and 0.85 for strategy 1, and 88.9%, 96.7%, and 0.81 for strategy 2.

CONCLUSIONS

West African MSM have a high prevalence of extragenital and asymptomatic STIs. The GeneXpert method provides an opportunity to move from syndromic toward etiological STI diagnosis in low-income countries, as the platform is available in African countries for tuberculosis testing. Pooling will reduce costs of triple site testing.

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

PURPOSE OF REVIEW

The combined incidence of chlamydia, gonorrhoea and syphilis in MSM PrEP (preexposure prophylaxis) cohorts now frequently exceeds 100 per 100 person years. The efficacy of antiretroviral PrEP in reducing HIV transmission has led to efforts to find similar biomedical ways reduce sexually transmitted infection (STI) incidence. We review the recent evidence for these and other strategies.

RECENT FINDINGS

Doxycycline PrEP/postexposure prophylaxis has been shown to reduce the incidence of syphilis and chlamydia but not gonorrhoea. A meningococcal vaccine has been found to result in a lower incidence of gonorrhoea. Novel insights into the role of the pharynx in the transmission of gonorrhoea have led to clinical trials of oral antiseptics to reduce the spread of gonorrhoea. Intensified STI screening has been introduced in a number of clinics. Serious concerns have however been raised about the emergence of resistance to each of these strategies. This is particularly true for doxycycline PrEP which is not advocated by any guidelines we reviewed.

SUMMARY

Randomized controlled trials are urgently required to ascertain the benefits and risks of interventions to reduce STIs in MSM PrEP cohorts.

Could Intensive Screening for Gonorrhea/Chlamydia in Preexposure Prophylaxis Cohorts Select for Resistance? Historical Lessons From a Mass Treatment Campaign in Greenland

INTRODUCTION

Neisseria gonorrhoeae has developed resistance to all classes of antimicrobials used against it. Current strategies to prevent the emergence of pan-resistance include increased gonorrhea screening in high-prevalence populations such as men who have sex with men taking HIV preexposure prophylaxis. By increasing antimicrobial exposure, others have argued that intensive screening may inadvertently promote the emergence of antimicrobial resistance.

AIM/METHODOLOGY

To contribute to this discussion, we conducted a historical review of the effect of a mass gonorrhea treatment campaign in Greenland from 1965 to 1968 on the incidence of gonorrhea and antimicrobial resistance. We conducted a literature review using PubMed and Google Scholar to find relevant studies. Data on the incidence of gonorrhea, antimicrobial susceptibility, and antimicrobials dispensed were extracted and analyzed.

RESULTS

Eight articles were found with relevant information. The cornerstone of the campaign involved the repeated treatment for all persons with a diagnosis of gonorrhea in the past 6 months as well as all remaining unmarried persons between 15 and 30 years of age. There was a small and temporary decline in the incidence of gonorrhea during the campaign. The campaign was, however, associated with an increase in the proportion of gonococci that were not susceptible to penicillin. Gonococcal incidence continued to climb after the campaign ended but did decline dramatically after reductions in risk behavior after the global AIDS epidemic.

DISCUSSIONS

The mass gonorrhea treatment campaign in Greenland was associated with only a temporary decline in the incidence of gonorrhea. It was, however, followed by an increase in penicillin nonsusceptibility. Intense gonorrhea screening and treatment strategies should be aware of the risk of inducing antimicrobial resistance.

Screening for STIs in PrEP cohorts results in high levels of antimicrobial consumption

Screening for STIs in men who have sex with men receiving HIV pre-exposure prophylaxis resulted in high consumption of macrolides, extended spectrum cephalosporins, fluoroquinolones and tetracyclines. The consumption of macrolides was 52 times as high as that reported for community-level consumption in certain European countries.

Association between STI screening intensity in men who have sex with men and gonococcal susceptibility in 21 States in the USA: an ecological study

OBJECTIVES

Antimicrobial resistance is generally linked to antimicrobial selection pressure. Antimicrobial-resistant Neisseria gonorrhoeae infections frequently emerge in core groups. We hypothesised that these groups are more often exposed to antimicrobials as a consequence of the repeated treatment of both symptomatic and asymptomatic sexually transmitted infections (STIs) and that frequent STI screening in asymptomatic patients may contribute indirectly to antimicrobial exposure. In this study, we explored the ecological association between screening intensity in men who have sex with men and antimicrobial susceptibility in N. gonorrhoeae in the USA.

METHODS

Data on STI screening intensity came from the American Men's Internet Survey between October 2014 and March 2015. Data on gonococcal susceptibility to azithromycin, ceftriaxone and cefixime were used from the Gonococcal Isolate Surveillance Project in 2015. Spearman's correlation was used to determine the association between these two variables.

RESULTS

A positive ecological association was found between STI screening intensity and geometric mean gonococcal minimum inhibitory concentration for ceftriaxone (rho=0.42, p=0.031) and cefixime (rho=0.42, p=0.029), but not for azithromycin (rho=0.31, p=0.11). The above results must be interpreted with caution as many limitations apply.

CONCLUSIONS

Variation in STI screening intensity may contribute to differences in gonococcal resistance between States in the USA.