Screening Peter to Save Paul: The Population-Level Effects of Screening Men Who Have Sex With Men for Gonorrhea and Chlamydia

Frequent screening for asymptomatic chlamydia and gonorrhoea infections in men who have sex with men: time to re-evaluate?

There is increasing debate regarding the harms and benefits of frequent asymptomatic screening for Chlamydia trachomatis and Neisseria gonorrhoeae in men who have sex with men (MSM). One concern is that frequent asymptomatic screening could result in increased antimicrobial resistance in an array of sexually acquired infections and other pathogens, due to selection pressure exerted by frequent broad-spectrum antimicrobial usage within some sexual networks. Here, we outline the harms and benefits of frequent C trachomatis and N gonorrhoeae screening in MSM in high-income settings and propose that screening frequency be reduced. We describe the evidence gaps that should be further explored to better understand the implications of reducing the frequency of asymptomatic C trachomatis and N gonorrhoeae screening in MSM and the surveillance systems that should be in place to prepare for such changes.

Comparison of the burden of self-reported bacterial sexually transmitted infections among men having sex with men across 68 countries on four continents

BACKGROUND

Men who have sex with men (MSM) are in general more vulnerable to sexually transmitted infections (STIs) than the heterosexual men population. However, surveillance data on STI diagnoses lack comparability across countries due to differential identification of MSM, diagnostic standards and methods, and screening guidelines for asymptomatic infections.

METHODS

We compared self-reported overall diagnostic rates for syphilis, gonorrhea, and chlamydia infections, and diagnostic rates for infections that were classified to be symptomatic in the previous 12 months from two online surveys. They had a shared methodology, were conducted in 68 countries across four continents between October 2017 and May 2018 and had 202,013 participants.

RESULTS

Using multivariable multilevel regression analysis, we identified age, settlement size, number of sexual partners, condom use for anal intercourse, testing frequency, sampling rectal mucosa for extragenital testing, HIV diagnosis, and pre-exposure prophylaxis use as individual-level explanatory variables. The national proportions of respondents screened and diagnosed who notified some or all of their sexual partners were used as country-level explanatory variables. Combined, these factors helped to explain differences in self-reported diagnosis rates between countries. The following differences were not explained by the above factors: self-reported syphilis diagnoses were higher in Latin America compared with Europe, Canada, Israel, Lebanon, and the Philippines (aORs 2.30 - 3.71 for symptomatic syphilis compared to Central-West Europe); self-reported gonorrhea diagnoses were lower in Eastern Europe and in Latin America compared with all other regions (aORs 0.17-0.55 and 0.34 - 0.62 for symptomatic gonorrhea compared to Central-West Europe); and self-reported chlamydia diagnoses were lower in Central East and Southeast Europe, South and Central America, and the Philippines (aORs 0.25 - 0.39 for symptomatic chlamydia for Latin American subregions compared to Central West Europe).

CONCLUSIONS

Possible reasons for differences in self-reported STI diagnosis prevalence likely include different background prevalence for syphilis and syndromic management without proper diagnosis, and different diagnostic approaches for gonorrhea and chlamydia.

Does Intense Sexually Transmitted Infection Screening Cause or Prevent Antimicrobial Resistance in Sexually Transmitted Infections? It Depends on One's Underlying Epistemology. A Viewpoint

Certain authors argue that intensive sexually transmitted infection (STI) screening is a crucial way to reduce STI prevalence and prevent the emergence and spread of antimicrobial resistance (AMR) in STIs. Others argue the opposite: intense screening in high STI prevalence populations has little effect on prevalence and is likely to select for AMR. In this viewpoint, I argue that these radical differences in outlook stem, in part, from different conceptual frameworks of the determinants of STI prevalence and AMR. In the absence of strong evidence from randomized controlled trials, our brains interpret the weaker evidence from other sources in different ways, depending on our underlying epistemologies. To illustrate the argument, I contrast a predominantly biomedical individualist conceptual framework with a more ecological conceptual framework. I argue that if one's conceptual framework is based in biomedical individualism, then one is more likely to think that screening reduces STI prevalence and less likely to appreciate the connection between screening, antimicrobial exposure, and AMR than perspectives grounded in ecological frameworks.

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.

Is There a Resistance Threshold for Macrolide Consumption? Positive Evidence from an Ecological Analysis of Resistance Data from Streptococcus pneumoniae, Treponema pallidum, and Mycoplasma genitalium

If we were to keep macrolide consumption below a certain threshold, would this reduce the probability of macrolide resistance emerging? No study that we are aware of has addressed this question. We, therefore, assessed at a country level if there was a macrolide consumption threshold for the selection of a prevalence of macrolide resistance of over 5% in Streptococcus pneumoniae, Treponema pallidum, and Mycoplasma genitalium. In this ecological-level analysis, we found evidence for a macrolide consumption threshold of 1.3 defined daily doses per 1,000 inhabitants per day (DID) for M. genitalium, 1.8 DID for T. pallidum, and 2.3 DID for S. pneumoniae. Our results provide further motivation for macrolide stewardship campaigns that strive to reduce macrolide consumption to levels below at least 2 DID.

Commensal Neisseria Are Shared between Sexual Partners: Implications for Gonococcal and Meningococcal Antimicrobial Resistance

Antimicrobial resistance in pathogenic Neisseria parallels reduced antimicrobial susceptibility in commensal Neisseria in certain populations, like men who have sex with men (MSM). Although this reduced susceptibility can be a consequence of frequent antimicrobial exposure at the individual level, we hypothesized that commensal Neisseria are transmitted between sexual partners. We used data from a 2014 microbiome study in which saliva and tongue swabs were taken from 21 couples (42 individuals). Samples were analyzed using 16S rRNA gene sequencing. We compared intimate partners with unrelated individuals and found that the oral Neisseria communities of intimate partners were more similar than those of unrelated individuals (average Morisita-Horn dissimilarity index for saliva samples: 0.54 versus 0.71, respectively (p = 0.005); and for tongue swabs: 0.42 versus 0.63, respectively (p = 0.006)). This similarity presumably results from transmission of oral Neisseria through intimate kissing. This finding suggests that intensive gonorrhea screening in MSM may, via increased antimicrobial exposure, promote, rather than prevent, the emergence and spread of antimicrobial resistance in Neisseria. Non-antibiotic strategies such as vaccines and oral antiseptics could prove more sustainable options to reduce gonococcal prevalence.

Prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis in men having sex with men in Port-au-Prince, Haiti: a cross-sectional study

OBJECTIVES

Over the last 15 years, the prevalence of HIV in Haiti has stabilised to around 2.0%. However, key populations remain at higher risk of contracting HIV and other sexually transmitted infections (STIs). The prevalence of HIV is 12.9% among men having sex with men (MSM). There is limited information about the prevalence of other STI in the Haitian population in general and even less among key populations. We assessed the burden of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) and risk factors for infections among MSM in Haiti.

METHODS

A cross-sectional study was conducted. MSM were recruited from seven health facilities in Port-au-Prince. All samples were tested by nucleic acid amplification test, using GeneXpert. A survey was administered to the participants to collect socio-demographic, clinical and risk behaviour data.

RESULTS

A total of 216 MSM were recruited in the study. The prevalence rates of CT and NG were 11.1% and 16.2%, respectively. CT NG co-infections were found in 10/216 (4.6%) of the participants. There were 39 MSM with rectal STI compared with 17 with genital infections. Participants between 18-24 and 30-34 years old were significantly more likely to be infected with NG than those aged 35 years or older (OR: 22.96, 95% CI: 2.79 to 188.5; OR: 15.1, 95% CI: 1.68 to 135.4, respectively). Participants who never attended school or had some primary education were significantly more likely to be infected with NG than those with secondary education or higher (OR: 3.38, 95% CI: 1.26 to 9.07). People tested negative for HIV were significantly more likely to be infected with CT than people living with HIV/AIDS (OR: 3.91, 95% CI: 1.37 to 11.2).

CONCLUSIONS

Periodic risk assessment and testing for STI should be offered in Haiti as part of a comprehensive strategy to improve the sexual health of key populations.

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.

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

Contemporary HIV preexposure prophylaxis (PrEP) cohorts are characterized by high rates of partner change and as a result have high and fairly stable prevalences of N. gonorrhoeae and C. trachomatis. The available evidence suggests that intensive 3-monthly screening in this setting does not have a large effect on the prevalence of these infections but results in high antimicrobial exposures. Gonorrhea/chlamydia screening may thus be doing more harm than good. Compelling arguments can, however, be made to screen for HIV, hepatitis C, and syphilis in PrEP cohorts. In this perspective piece, we explore the logical basis for deciding which STIs to screen for in PrEP cohorts. We propose that a Delphi consensus methodology is used to derive, assess, and apply a broadly accepted set of criteria to evaluate which STIs to screen for in these cohorts. Finally, to illustrate the utility of the process, we derive and apply our own list of criteria as to which STIs to screen for. This process leads to a controversial conclusion, namely that stopping gonorrhea/chlamydia screening in a controlled and phased manner may offer net health benefits to PrEP cohorts.

Screening is not associated with reduced incidence of gonorrhoea or chlamydia in men who have sex with men (MSM); an ecological study of 23 European countries

Background: Increasing rates of antimicrobial resistance has motivated a reassessment of if intensive screening for gonorrhoea and chlamydia is associated with a reduction in the prevalence of these infections in men who have sex with men (MSM).

Methods: Spearman’s correlation was used to evaluate the country-level correlation between the intensity of self-reported sexual transmitted infection (STI) screening in MSM (both anal and urethral screening, taken from a large internet survey of MSM) and the incidence (taken from ECDC surveillance figures) and prevalence (taken from a literature review of studies estimating prevalence in MSM attending STI clinics) of gonorrhoea and chlamydia.

Results: The intensity of both anal and genital screening was found to be positively associated with country level gonorrhoea incidence rates (rho 0.74; p=0.0004; rho=0.73; p=0.0004, respectively) and Ct incidence rates (rho 0.71; p=0.001; rho=0.78; p=0.0001, respectively). No associations were found between anal or genital screening intensity and Ng prevalence in clinic populations (Table 2).

Conclusions: We found no evidence of a negative association between screening intensity and the prevalence of gonorrhoea or chlamydia in MSM. Randomized controlled trials are urgently required to evaluate if the high antimicrobial exposure resulting from intensive screening programmes is justified.

Screening is not associated with reduced incidence of gonorrhoea or chlamydia in men who have sex with men (MSM); an ecological study of 23 European countries

Background: Increasing rates of antimicrobial resistance has motivated a reassessment of if intensive screening for gonorrhoea and chlamydia is associated with a reduction in the prevalence of these infections in men who have sex with men (MSM). Methods: Spearman's correlation was used to evaluate the country-level correlation between the intensity of self-reported sexual transmitted infection (STI) screening in MSM (both anal and urethral screening, taken from a large internet survey of MSM) and the incidence (taken from ECDC surveillance figures) and prevalence (taken from a literature review of studies estimating prevalence in MSM attending STI clinics) of gonorrhoea and chlamydia. Results: The intensity of both anal and genital screening was found to be positively associated with country level gonorrhoea incidence rates (rho 0.74; p=0.0004; rho=0.73; p=0.0004, respectively) and Ct incidence rates (rho 0.71; p=0.001; rho=0.78; p=0.0001, respectively). No associations were found between anal or genital screening intensity and Ng prevalence in clinic populations (Table 2). Conclusions: We found no evidence of a negative association between screening intensity and the prevalence of gonorrhoea or chlamydia in MSM. Randomized controlled trials are urgently required to evaluate if the high antimicrobial exposure resulting from intensive screening programmes is justified.