Spontaneous Clearance of Pharyngeal Gonococcal Infections: A Retrospective Study in Patients of the Sexually Transmitted Infections Clinic; Amsterdam, the Netherlands; 2012 to 2015

Bacterial sexually transmitted infections are concentrated in subpopulations of men who have sex with men using HIV pre-exposure prophylaxis

OBJECTIVE

Studies have shown varying trends in incidence of sexually transmitted infections (STIs) among individuals using HIV pre-exposure prophylaxis (PrEP). Characterization of individuals at increased risk for STIs may offer an opportunity for targeted STI screening.

DESIGN

Group-based trajectory modeling.

METHODS

We screened participants from the AMPrEP demonstration project (2015-2020) for urogenital, anal, and pharyngeal chlamydia and gonorrhea, and syphilis every 3 months and when needed. We identified trajectories of STI incidence within individuals over time and determinants of belonging to a trajectory group. We calculated cumulative proportions of STIs within STI trajectory groups.

RESULTS

Three hundred and sixty-six participants with baseline and at least one screening visit during follow-up were included (median follow-up time = 3.7 years [interquartile range, IQR = 3.5-3.7]). We identified three trajectories of STI incidence: participants with a mean of approximately 0.1 STIs per 3 months ('low overall', 52% of the population), participants with a mean 0.4 STI per 3 months ('medium overall', 43%), and participants with high and fluctuating (between 0.3 and 1 STIs per 3 months) STI incidence ('high and fluctuating', 5%). Participants in the 'low overall' trajectory were significantly older, and reported less chemsex and condomless anal sex with casual partners than participants in the other trajectories. Participants in the 'high and fluctuating' and 'medium overall' groups accounted for respectively 23 and 64% of all STIs observed during follow-up.

CONCLUSIONS

STI incidence was concentrated in subpopulations of PrEP users who were younger, had more chemsex and condomless anal sex. Screening frequency for STIs could be reduced for subpopulations with low risk for incident STIs.

Spontaneous clearance of asymptomatic anogenital and pharyngeal Neisseria gonorrhoeae: a secondary analysis from the NABOGO trial

INTRODUCTION

Spontaneous clearance of asymptomatic Neisseria gonorrhoeae (NG) does occur, but data are scarce. We aimed to assess spontaneous clearance among patients with asymptomatic anal, pharyngeal, vaginal and urethral NG infections who participated in the New AntiBiotic treatment Options for uncomplicated GOnorrhoea (NABOGO) trial. In addition, we assessed the determinants associated with spontaneous clearance.

METHODS

The NABOGO trial (Trial registration number: NCT03294395) was a randomised controlled, double-blind, single-centre trial assessing non-inferiority of ertapenem, gentamicin and fosfomycin to ceftriaxone for treatment of uncomplicated gonorrhoea. For asymptomatic NABOGO participants, we collected pre-enrolment and enrolment visit samples before trial medication was given. Spontaneous clearance was defined as a positive pre-enrolment nucleic acid amplification test (NAAT) result, followed by a negative NAAT at enrolment. We compared the median time between pre-enrolment and enrolment visits for patients who cleared spontaneously and for those who did not. Determinants of spontaneous clearance were assessed using logistic regression.

RESULTS

Thirty-two of 221 (14.5%) anal NG infections cleared spontaneously, 17 of 91 (18.7%) pharyngeal, 3 of 13 (23.1%) vaginal and 9 of 28 (32.1%) urethral NG infections. The median time between the pre-enrolment and enrolment visit was longer for patients who cleared their pharyngeal infection spontaneously compared with those who did not (median 8 days (IQR=7-11) vs 6 days (IQR=4-8), p=0.012); no determinants of clearance at other sites were identified. Overall, patients with more days between the pre-enrolment and enrolment visit were more likely to clear spontaneously (adjusted OR=1.06 per additional day, 95% CI 1.01 to 1.12). No association between location of NG infection and spontaneous clearance was found.

CONCLUSIONS

A significant proportion of asymptomatic patients cleared their NG infections spontaneously. Given these results, treatment of all NG infections after a one-time NAAT may be excessive, and more research on the natural history of NG is needed to improve antibiotic stewardship.

Can we screen less frequently for STI among PrEP users? Assessing the effect of biannual STI screening on timing of diagnosis and transmission risk in the AMPrEP Study

BACKGROUND

In many countries, HIV pre-exposure prophylaxis (PrEP) users are screened quarterly for STIs. We assessed the consequences of less frequent STI testing. We also assessed determinants of asymptomatic STI and potential for onward transmission.

METHODS

Using data from the AMPrEP study, we assessed the proportion of syphilis, and genital, anal, and pharyngeal chlamydia and gonorrhoea diagnoses which would have been delayed with biannual versus quarterly screening. We assessed the potential for onward transmission by examining reported condomless anal sex (CAS) in periods after to-be-omitted visits when screening biannually. We assessed determinants of incident asymptomatic STIs using Poisson regression and calculated individual risk scores on the basis of the coefficients from this model.

RESULTS

We included 366 participants. Median follow-up was 47 months (IQR 43-50). 1,183STIs were diagnosed, of which 932(79%) asymptomatic. With biannual screening, 483 asymptomatic STIs (52%) diagnoses would have been delayed at 364 study visits. Of these visits, 129 (35%), 240 (66%) and 265 (73%) were followed by periods of CAS with steady, known casual or unknown casual partners, respectively. Older participants had a lower risk of asymptomatic STI (incidence rate ratio (IRR) 0.86/10-year increase, 95% CI 0.80 to 0.92), while CAS with known (IRR 1.36, 95% CI 1.10 to 1.68) and unknown (IRR 1.86, 95% CI 1.48 to 2.34) casual partners and chemsex (IRR 1.51, 95% CI 1.28 to 1.78) increased the risk. The individual risk scores had limited predictive value (sensitivity=0.70 (95% CI 0.66 to 0.74), specificity=0.50 (95% CI 0.48 to 0.51)).

CONCLUSION

Reducing the STI screening frequency to biannually among PrEP users will likely result in delayed diagnoses, potentially driving onward transmission. Although determinants for asymptomatic STIs were identified, predictive power was low.

Oropharyngeal gonorrhoea infections among heterosexual women and heterosexual men with urogenital gonorrhoea attending a sexual health clinic in Melbourne, Australia

OBJECTIVES

There is limited evidence about the transmission and prevalence of oropharyngeal gonorrhoea in heterosexuals. From August 2017, Melbourne Sexual Health Centre (MSHC) began testing for oropharyngeal gonorrhoea among heterosexuals with untreated urogenital gonorrhoea. This study aims to determine the positivity of oropharyngeal gonorrhoea among heterosexuals diagnosed with urogenital gonorrhoea at MSHC between August 2017 and May 2020.

METHODS

We included individuals who had oropharyngeal gonorrhoea testing within 30 days of initial testing. We reported the number and proportion of oropharyngeal gonorrhoea positivity, stratified by gender and contact of gonorrhoea. The χ² test was performed to compare the oropharyngeal gonorrhoea positivity between groups.

RESULTS

Of 617 individuals with untreated urogenital gonorrhoea, 424 (68.7%) were tested for oropharyngeal gonorrhoea. Oropharyngeal gonorrhoea positivity was 38.9% (95%CI 34.2-43.7%, 165/424), and was higher in women than in men (115/252, 45.6% versus 50/172, 29.1%, p = 0.001). Furthermore, oropharyngeal gonorrhoea positivity was higher among individuals who were contacts of gonorrhoea cases compared to those who were not (29/44, 65.9% versus 136/380, 35.8%, p < 0.001). There was also no significant difference between women who were sex workers and those who were not (30/78, 38.5% versus 85/174, 48.9%, p = 0.126).

CONCLUSIONS

Our data suggest that oropharyngeal gonorrhoea infection is common among heterosexual women and heterosexual men with untreated urogenital gonorrhoea. Testing heterosexual women and heterosexual men for oropharyngeal gonorrhoea will identify a significant proportion with unrecognized oropharyngeal infections whose recommended treatment is different in some countries.

What Is the Optimal Testing Strategy for Oropharyngeal Neisseria gonorrhoeae in Men Who Have Sex With Men? Comparing Selective Testing Versus Routine Universal Testing From Dutch Sexually Transmitted Infection Clinic Data (2008-2017)

BACKGROUND

Most oropharyngeal Neisseria gonorrhoeae infections are asymptomatic, and many infections remain undetected, creating a reservoir for ongoing transmission and potential drug resistance. It is unclear what the optimal testing policy is in men who have sex with men (MSM), as routine universal testing data are lacking.

METHODS

Surveillance data from all Dutch sexually transmitted infection (STI) clinics between 2008 and 2017 were used (N = 271 242 consultations). Oropharyngeal testing policy was defined as routine universal testing when ≥85% of consultations included oropharyngeal testing or as selective testing (<85% tested). Independent risk factors for oropharyngeal N. gonorrhoeae were assessed among MSM routinely universally screened using backward multivariable logistic regression analyses.

RESULTS

Routine universal testing was performed in 90% (238 619/265 127) of consultations. Prevalence was higher using routine universal testing (5.5%; 95% CI, 5.4-5.6; 12 769/233 476) than with selective testing (4.7%; 95% CI, 4.4-5.0; 799/17 079; P < .001). Proportions of oropharyngeal-only infections were 55% and 47%, respectively. Independent risk factors were age <31 years (OR, 2.1; 95% CI, 1.9-2.3), age 31-43 years (OR, 1.7; 95% CI, 1.6-1.9, compared with >43 years), being notified for any STI (OR, 2.0; 95% CI, 1.9-2.1), concurrent urogenital N. gonorrhoeae (OR, 2.4; 95% CI, 2.1-2.7), and concurrent anorectal N. gonorrhoeae (OR, 11.4; 95% CI, 10.6-12.3). When using any of the risk factors age, notified, or oral sex as testing indicators, 98.4% (81 022/82 332) of MSM would be tested, finding 99.5% (4814/4838) of infections.

CONCLUSIONS

Routine universal testing detected more oropharyngeal N. gonorrhoeae infections than selective testing, of which more than half would be oropharyngeal only. Using independent risk factors as testing indicator is not specific. Therefore, routine universal oropharyngeal testing in MSM is feasible and warranted, as currently advised in most guidelines.

Routine universal testing versus selective or incidental testing for oropharyngeal Neisseria gonorrhoeae in women in the Netherlands: a retrospective cohort study

BACKGROUND

Women are not routinely tested for oropharyngeal Neisseria gonorrhoeae. At present, selective testing based on sexual behaviour or risk groups is advocated by international guidelines. Many oropharyngeal infections are asymptomatic and thus remain undetected, establishing a reservoir for ongoing transmission. Data on effectiveness of routine testing are scarce, thus we aimed to assess the optimal testing strategy for oropharyngeal N gonorrhoeae in women.

METHODS

In this retrospective cohort study, we used surveillance data obtained from all sexually transmitted infection (STI) clinics in the Netherlands between Jan 1, 2008, and Dec 31, 2017. We collected consultation-level data, and individual-level patient data from 2016 onwards, on sociodemographic characteristics, sexual behaviour in the past 6 months, self-reported symptoms, and STI diagnoses. We compared the prevalence of oropharyngeal N gonorrhoeae between women who attended clinics that offered routine universal testing (defined as >85% of women tested per clinic-year) and women who attended clinics that offered selective testing (defined as 5-85% of women tested per clinic-year) or incidental testing (<5% of women tested per clinic-year). We calculated the number of infections missed by selective testing by extrapolating prevalence for the routine universal testing group to that of weighted and unweighted samples of all selectively tested women. We used multivariable generalised estimating equations to identify independent risk factors for oropharyngeal N gonorrhoeae to identify the optimal selective testing strategy.

FINDINGS

554 266 consultations with at least one N gonorrhoeae test were recorded, of which 545 750 consultations (including repeat visits) were included in the analyses. Of 545 750 consultations, routine universal testing was used in 57 359 (10·5%), selective testing in 444 283 (81·4%), and incidental testing in 44 108 (8·1%). The prevalence of oropharyngeal N gonorrhoeae was 1·4% (95% CI 1·3-1·5; 703 of 50 962 consultations) in the routine testing group compared with 1·4% (1·3-1·5; 1858 of 132 276) in the selective testing group (p=0·68) and 2·8% (1·9-3·9; 30 of 1088) in the incidental testing group (p<0·0001). The prevalence of oropharyngeal-only infections was 47·7% (335 of 703 women) in the routine testing group, 53·3% (991 of 1858) in the selective testing group, and 60·0% (18 of 30) in the incidental testing group. Selective testing would have missed an estimated 4363 (70%; 95% CI 69-71) of all 6221 oropharyngeal N gonorrhoeae infections. Independent risk factors for oropharyngeal N gonorrhoeae were being notified for any STI (adjusted odds ratio 2·1, 95% CI 1·5-3·0), reporting sex work (4·0, 2·3-6·7), and having concurrent genital (51·5, 34·1-77·7) or anorectal (2·6, 1·4-4·8) N gonorrhoeae. Selective testing of women notified for any STI, or who reported sex work, would have led to 5418 (27·8%) of 19 455 women being tested and would have identified 119 (55·6%) of 214 oropharyngeal N gonorrhoeae infections.

INTERPRETATION

Selective testing potentially misses more than two-thirds of oropharyngeal N gonorrhoeae infections in women, of whom half have oropharyngeal infections without concurrent genital or anorectal infections. Using independent risk factors for oropharyngeal infection to guide testing is a minimal testing strategy. Routine universal testing is the optimum scenario to detect the majority of infections. However, future studies are needed to assess the cost-effectiveness of routine testing and its effect on antimicrobial resistance.

FUNDING

Public Health Service South Limburg.

Optimizing Strategies for Chlamydia trachomatis and Neisseria gonorrhoeae Screening in Men Who Have Sex With Men: A Modeling Study

BACKGROUND

International guidelines recommend the systematic screening for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infections in all men who have sex with men (MSM) who have engaged in unprotected sex. However, the optimal screening strategy remains unclear. We developed a modeling approach to optimize NG/CT screening strategy in MSM.

METHODS

A compartmental model of NG/CT screening and infection was implemented. NG/CT anal, pharyngeal, and urine (APU) samples from MSM attending the sexually transmitted infections clinic were used to estimate the screening rate, prevalence, and incidence in a base case scenario. Different screening strategies (scenarios; S) were then evaluated: APU samples every 12 months (S1); APU samples every 3 months (S2); APU samples every 6 months (S3); anal and pharyngeal (AP) samples every 6 months (S4); and AP samples every 3 months (S5).

RESULTS

We analyzed 2973 triplet APU samples from 1255 patients. We observed 485 NG and 379 CT diagnoses. NG/CT prevalence and incidence estimates were 12.0/11.1% and 40/29 per 100 person-years, respectively, in the base case scenario. As compared to S2, the reference strategy, the proportions of missed NG/CT diagnoses were 42.0/41.2% with S1, 21.8/22.5% with S3, 25.6/28.3% with S4, and 6.3/10.5% with S5, respectively. As compared to S2, S1 reduced the cost of the analysis by 74%, S3 by 50%, S4 by 66%, and S5 by 33%. The numbers needed to screen for catching up the missed NG/CT diagnoses were 49/67 with S1, 62/82 with S3, 71/87 with S4, and 143/118 with S5.

CONCLUSIONS

S5 appears to be the best strategy, missing only 6.3/10.5% of NG/CT diagnoses, for a cost reduction of 33%.

Increases in pharyngeal Neisseria gonorrhoeae positivity in men who have sex with men, 2011-2015: observational study

OBJECTIVES

Pharyngeal gonorrhoea disproportionately affects men who have sex with men (MSM). We explored temporal trends in pharyngeal gonorrhoea positivity among MSM compared with anorectal and urogenital positivity.

METHODS

Data (2011-2015) were extracted from 41 publicly funded sexual health clinics participating in a national surveillance network. Positivity was defined as the proportion of first-visit testing occasions where gonorrhoea was detected. Logistic regression explored trends in positivity and correlates of positive pharyngeal tests.

RESULTS

From 2011 to 2015, 24 792 MSM tested (16 710 pharyngeal, 19 810 urogenital and 15 974 anorectal first-visit tests). Pharyngeal positivity increased by 183% from 139/3509 (4.0%) in 2011 to 397/3509 (11.3%) in 2015, p-trend <0.001; urogenital positivity by 39% from 257/4615 (5.6%) to 295/3783 (7.8%), p-trend=0.006; and anorectal positivity by 87% from 160/3469 (4.6%) to 286/3334 (8.6%), p-trend <0.001. The annual temporal increase in positivity was greater in the pharynx (OR 1.33; 95% CI 1.27 to 1.38) than at urogenital (OR 1.06; 95% CI 1.02 to 1.10) and anorectal (OR 1.16; 95% CI 1.11 to 1.21) sites. Factors independently associated with pharyngeal gonorrhoea were: younger age (p<0.001), higher numbers of recent sexual partners (p-trend=0.004), contact with a person with a diagnosed STI (p<0.001), injecting drug use (p<0.001), anogenital symptoms (p<0.001) and HIV-positive status (p=0.050).

CONCLUSION

Temporal increases in gonorrhoea positivity occurred at all anatomical sites, with the greatest increase in the pharynx. Risk factors could be used to help to develop testing and prevention strategies among MSM at highest risk. Strengthening sexual health service delivery, testing and surveillance remain priorities for pharyngeal gonorrhoea control.

Comparison between Aptima Assays (Hologic) and the Allplex STI Essential Assay (Seegene) for the diagnosis of Sexually transmitted infections

Sexually transmitted infections (STIs) remain a worldwide problem and a severe threat to public health. The purpose of this study was to compare Aptima^® Assays (Hologic^®) and the Allplex^™ STI Essential Assay (Seegene^®) for the simultaneous detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium in clinical practice. The Aptima^® assays (Hologic^®) are based on a transcription-mediated amplification (TMA) method. The Allplex^™ STI Essential assay (Seegene^®) is based on a multiplex Real-Time PCR (RT-PCR) method. A total of 622 clinical samples from different anatomical sites were tested using both methods. A total of 88 (14.1%) and 66 (10.6%) positive samples were found for any of the TMA assays used and for the RT-PCR assay, respectively. Aptima^® assays showed a slightly higher rate of positive results for all pathogens except for T. vaginalis, the results of which were similar to those obtained with Allplex^™. The most commonly detected pathogen was C. trachomatis (37 samples; 5.9% using TMA assays) and the anatomical site with the highest prevalence of microorganisms was a non-urogenital site, the pharynx (27 positive samples; 4.3%). Using the Aptima^® assays as reference method, the comparison showed that the average specificity of multiplex RT-PCR was 100.0% for the four pathogens. However an average sensitivity of 74.5% was observed, showing 95.2% (CI95%; 93.6–96.9) of overall concordance (κ = 0.80). In conclusion, the Aptima^® assays show a higher sensitivity on a wide range of sample types compared to the Allplex^™ assay.

Kissing, saliva exchange, and transmission of Neisseria gonorrhoeae

Data from mathematical models suggest that kissing and saliva exchange during sexual activity might be major contributors to community gonorrhoea morbidity. Although there is little evidence to support this, it provokes discussion of the potential role of the oropharynx in gonorrhoea control. Improved sensitivity and ease of diagnostic testing, as well as increased screening for extragenital infections among men who have sex with men, have increased awareness of the high frequency of oropharyngeal gonorrhoea. However, there are insufficient data to determine the mechanisms of transmission for these infections. Innovative studies that use quantitative microbiological techniques are needed to accurately assess how oral gonorrhoea or saliva exchange in infected people contribute to the morbidity of gonorrhoea in the community. More empirical data on pharyngeal gonorrhoea infections, and the role of transmission to and from the oropharynx, are needed to inform prevention planning.

Spontaneous clearance of urogenital, anorectal and oropharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae in women, MSM and heterosexual men visiting the STI clinic: a prospective cohort study

OBJECTIVE

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections can clear without treatment. Despite high prevalence of anorectal infections in men who have sex with men (MSM) and women, studies on anorectal clearance are scarce. Moreover it is unknown whether bacterial load affects urogenital/anorectal CT clearance. In this prospective cohort study, CT and NG clearance is assessed at three anatomical sites of men and women.

METHODS

CT-positive and NG-positive MSM, heterosexual men and women ≥18 years of age visiting our STI clinic between 2011 and 2013 underwent a repeat test when returning for treatment (n=482). The primary outcome was clearance, defined as a positive nucleic acid amplification test (NAAT) at screening-consultation, followed by a negative NAAT at treatment-consultation. Sociodemographics, sexual risk behaviour and CT bacterial load (inhouse quantitative PCR) were tested as determinants for clearance using multivariable logistic regression for CT and Fisher's exact test for NG.

RESULTS

CT clearance was 9.1% (10/110) for urine, 6.8% (20/292) for vaginal swabs, 12.7% (8/63) for anorectal swabs (ie, 4.0% [1/25] in MSM and 18.4% [7/38] in women) and 57.1% (4/7) for oropharyngeal swabs. For NG this was 33.3% (2/6), 28.6% (2/7), 20.0% (2/10) and 27.3% (6/22), respectively. The number of days between tests (median 10, IQR 7-14) was not associated with clearance. Lower bacterial load at screening was the only predictor for CT clearance (urine mean 1.2 vs 2.6 log CT/mL, p=0.001; vaginal swabs mean 2.1 vs 5.2 log CT/mL p<0.0001; anorectal swabs mean 2.0 vs 3.7 log CT/mL, p=0.002). None of the tested determinants were associated with NG clearance.

CONCLUSIONS

This study reports the largest number of anorectal infections tested for CT and NG clearance to date. Clearance in all sample types was substantial: between 7% and 57% for CT, and between 20% and 33% for NG (notwithstanding low absolute numbers). CT clearance was associated with a lower load at screening. However, not all individuals with low bacterial CT load cleared the infection, hampering STI guideline change.