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

Managing treatment failure in Neisseria gonorrhoeae infection: current guidelines and future directions

Due to the continued emergence of resistance to extended-spectrum cephalosporin antibiotics, clinicians are increasingly more likely to encounter cases of Neisseria gonorrhoeae treatment failure. The current international treatment guidelines offer few regimens for cases of N gonorrhoeae infection that do not respond to first-line therapy, and there are many complexities that should be considered with such regimens; these include regional variations in resistance to alternative agents, access to different antibiotics, and penetration of those antibiotics within different tissues. Further, such regimens do not account for the challenges of treating pharyngeal infections; many patients who have not responded to treatment with extended-spectrum cephalosporin antibiotics to date have had pharyngeal involvement. In addition, pharyngeal infections play a pivotal role in the emergence and spread of antimicrobial resistance in N gonorrhoeae and are more difficult to treat than urogenital infections because of the unfavourable pharmacokinetics of cephalosporins in pharyngeal tissues. Here, we summarise the current guidelines, provide additional approaches and considerations for clinicians, and highlight knowledge gaps that should be addressed to ensure appropriate therapy in cases of treatment failure.

STI pathogens in the oropharynx: update on screening and treatment

PURPOSE OF REVIEW

The rise in antimicrobial resistance in several STI pathogens such as Neisseria gonorrhoeae has become a public health threat as only one first-line treatment remains. Reducing screening interval for gonorrhoea and chlamydia in high-prevalence populations has been proposed to address antimicrobial stewardship, but this remains controversial. This review aimed to revisit the epidemiology of infections at the oropharynx and review the current screening recommendations and treatment guidelines in different populations.

RECENT FINDINGS

Emerging evidence suggests that the oropharynx is the primary anatomical site for gonorrhoea transmission but maybe not for chlamydia transmission. Most international guidelines recommend 3-monthly oropharyngeal gonorrhoea and chlamydia screening for high-prevalence populations (e.g. men who have sex with men) but not low-prevalence populations (e.g. heterosexuals) given the clinical and public health benefits of screening in low-prevalence populations are still unclear. Doxycycline remains the first-line treatment for oropharyngeal chlamydia in most guidelines. However, some countries have moved from dual therapy (ceftriaxone and azithromycin) to monotherapy (ceftriaxone) for oropharyngeal gonorrhoea treatment to address antimicrobial stewardship.

SUMMARY

The transmission of gonorrhoea and chlamydia is still not fully understood. Further work will be required to evaluate the benefits and harms of reducing screening in high-prevalence populations.

Within-Host Genetic Variation in Neisseria gonorrhoeae over the Course of Infection

Knowledge of within-host genetic variation informs studies on transmission dynamics. We studied within-host genetic variation in Neisseria gonorrhoeae over the course of infection and across different anatomical locations. Isolates were obtained during a clinical trial, and isolates from consecutive time points reflected persistent infections after treatment failure. We compared sequence types (STs) and recombination unfiltered- and filtered core genome single nucleotide polymorphism (SNP) distances in 65 within-host isolate pairs from the same anatomical location over time-obtained with a median interval of 7 days-and 65 isolate pairs across different anatomical locations at one time point. Isolates with different Multi-Locus Sequence Types (MLST), NG-Sequence Types for Antimicrobial Resistance (NG-STAR) and NG-Multi Antigen Sequence Types (NG-MAST) had a median of 1466 recombination filtered SNPs, whereas a median of 1 SNP was found between isolates with identical STs or a different NG-MAST only. The threshold for differentiating between strains was set at 10 recombination filtered SNPs, showing that isolates from persistent infections could have different NG-MASTs. Antibiotic pressure applied through treatment did not lead to an increase in genetic variation in specific genes or in overall extent of variation, compared to variation across anatomical locations. Instead, within-host genetic variation was proposedly driven by the host immune response, as it was concentrated in genomic regions encoding surface exposed proteins involved in host-microbe interaction. Ultimately, 15/228 (6.5%) between-host pairs contained a single strain, suggesting between-host transmission. However, patient reported data are needed to differentiate within-host persistence from between-host transmission. IMPORTANCE Understanding transmission dynamics of Neisseria gonorrhoeae (Ng) is based on the identification of transmission events. These can be identified by assessing genetic relatedness between Ng isolates, expressed as core genome SNP distances. However, a SNP threshold to differentiate between strains needs to be defined, using knowledge on within- and between-host genetic variation. Here, we assessed within-host genetic variation, using a unique set of within-host Ng isolates from the same anatomical location over time or across different anatomical locations at one time point. The insights in genetic variation that occurred during the infection period contribute to the understanding of infection dynamics. In addition, the obtained knowledge can be used for future research on transmission dynamics and development of public health interventions based on bacterial genomic data.

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

BACKGROUND

Pharyngeal Chlamydia trachomatis in women might contribute to autoinoculation and transmission to sexual partners. Data for effectiveness of different testing practices for pharyngeal C trachomatis are scarce. We therefore aimed to assess the prevalence of pharyngeal C trachomatis, determinants, and effectiveness of different testing practices in women.

METHODS

We did a retrospective cohort study, in which surveillance data for all women visiting sexually transmitted infection clinics in all regions in the Netherlands between Jan 1, 2008, and Dec 31, 2017, were used. We collected consultation-level data and individual-level data from 2016 onwards for sociodemographic characteristics, sexual behaviour in the past 6 months, self-reported symptoms, and STI diagnoses. The primary outcome was the positivity rate of pharyngeal C trachomatis infection compared between routine universal testing (>85% tested pharyngeally per clinic year), selective testing (5-85% tested pharyngeally per clinic year), and incidental testing (<5% pharyngeally tested per clinic year). We calculated the number of missed infections by extrapolating the positivity rate assessed by routine universal testing to all selectively tested women. We used multivariable generalised estimating equations logistic regression analyses to assess independent risk factors for pharyngeal C trachomatis and used the assessed risk factors as testing indicators for comparing alternative testing scenarios.

FINDINGS

Between Jan 1, 2008, and Dec 31, 2017, a total of 550 615 consultations with at least one C trachomatis test was recorded, of which 541 945 (98·4%) consultations (including repeat visits) were included in this analysis. Pharyngeal C trachomatis positivity was lower in the routine universal testing group than in the selective testing group (1081 [2·4%; 95% CI 2·2-2·5] of 45 774 vs 3473 [2·9%; 2·8-3·0] of 121 262; p<0·0001). The positivity rate was also higher among consultations done in the incidental testing group (44 [4·1%; 95% CI 3·1-5·5] of 1073; p<0·0001) than in the routine universal testing group. Based on extrapolation, selective testing would have hypothetically missed 64·4% (95% CI 63·5-65·3; 6363 of 9879) of the estimated total of C trachomatis infections. The proportion of pharyngeal-only C trachomatis was comparable between routinely universally tested women (22·9%) and selectively tested women (20·4%), resulting in a difference of 2·5% (95% CI -0·3 to 5·3; p=0·07). When using risk factors for pharyngeal C trachomatis as testing indicators, 15 484 (79·6%) of 19 459 women would be tested to detect 398 (80·6%) of 494 infections.

INTERPRETATION

No optimal testing scenario was available for pharyngeal C trachomatis, in which only a selection of high-risk women needs to be tested to find most pharyngeal C trachomatis infections. The relative low prevalence of pharyngeal-only C trachomatis (0·5%) and probably limited clinical and public health effect do not provide support for routine universal testing.

FUNDING

Public Health Service South Limburg.

A cross-sectional study of male and female kissing partners among men who have sex with men

BACKGROUND

Kissing may be a risk factor for gonorrhoea. Past studies have focused on male kissing partners among men who have sex with men (MSM). This study aimed to examine the kissing practices of MSM who kiss male and female partners.

METHODS

We conducted a cross-sectional survey at the Melbourne Sexual Health Centre (MSHC) between March and April 2019. Men attending the MSHC, aged ≥16years who reported any sexual contact with another man in the previous 12months were invited to participate in the survey. Data about the number of kissing-only (kissing without sex), kissing-with-sex, and sex-only (having sex without kissing) partners in the previous 3months were collected. Men were asked to report the number of male and female partners separately.

RESULTS

There were 357 MSM included in the survey. Most men (97.2%, n=347) had kissed or had sex with another man, whereas 16.0% (n=57) had kissed or had sex with a female partner in the previous 3months. Of the 57 men, 26.3% (n=15) had only kissed a female partner without having sex. The mean number of male partners for kissing-only was 5.5 (s.d.=6.6), kissing-with-sex was 5.0 (s.d.=6.6) and sex-only was 3.9 (s.d.=4.3). The mean number of female partners for kissing-only was 4.2 (s.d.=6.9), kissing-with-sex was 3.8 (s.d.=4.9) and sex-only was 3.2 (s.d.=3.4).

CONCLUSION

MSM not only kiss men in the absence of sex, but also kiss women in the absence of sex. Gonorrhoea could be transmitted between MSM and women via kissing in the absence of sex.

Pharyngeal Chlamydia trachomatis in Men Who Have Sex With Men (MSM) in The Netherlands: A Large Retrospective Cohort Study

Pharyngeal Chlamydia trachomatis (CT) was diagnosed in 1.2% and pharyngeal-only CT in 0.5% of routinely universally tested men who have sex with men (MSM). In these 3-anatomic-site tested MSM, pharyngeal-only CT comprised 4.8% of all CT. The low positivity of pharyngeal-only CT indicates low public health impact of pharyngeal CT.

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.