Test of cure study: a feasibility study to estimate the time to test of cure (TOC) for Neisseria gonorrhoeae and Chlamydia trachomatis infections.

OBJECTIVES: Test of cure (TOC) for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infection is an important tool in the public health management of STIs. However, there are limited data about the optimal time to perform TOC using nucleic acid amplification tests (NAATs) for NG and CT infections. A study was performed to assess the feasibility of a larger study to determine the optimal time to TOC using NAATS. METHODS: The Sexually Transmitted Bacteria Reference Unit at Public Health England undertook testing of gonococcal and chlamydial nucleic acids within neat urine stored in different conditions over 25 days to provide evidence of the stability of the nucleic acid prior to recruitment. Individuals diagnosed with uncomplicated NG or CT infection were recruited from three sexual health clinics. Individuals were asked to return nine self-taken samples from the site of infection over a course of 35 days. Survival analyses of time to first negative NAAT result for NG and CT infection and univariate regression analysis of factors that affect time to clearance were undertaken. RESULTS: At room temperature, chlamydial DNA in urine is stable for up to 3 weeks and gonococcal DNA for up to 11 days. We analysed data for 147 infections (81 NG and 66 CT). The median time to clearance of infection was 4 days (IQR 2-10 days) for NG infection and 10 days (IQR 7-14 days) for CT infection. Vaginal CT infections took longer to clear (p=0.031). NG infection in men who have sex with men took longer to clear (p=0.052). CONCLUSION: Chlamydial and gonococcal nucleic acids are stable in urine before addition of preservatives, longer than recommended by the manufacturer. The TOC results suggest that it may be possible to undertake TOC for NG and CT infections earlier than current guidelines suggest and that anatomical site of infection may affect time to clearance of infection.

Antimicrobial resistance in Mycoplasma genitalium sampled from the British general population.

BACKGROUND: Mycoplasma genitalium is a common sexually transmitted infection. Treatment guidelines focus on those with symptoms and sexual contacts, generally with regimens including doxycycline and/or azithromycin as first-line and moxifloxacin as second-line treatment. We investigated the prevalence of antimicrobial resistance (AMR)-conferring mutations in M. genitalium among the sexually-active British general population. METHODS: The third national survey of sexual attitudes and lifestyles (Natsal-3) is a probability sample survey of 15 162 men and women aged 16-74 years in Britain conducted during 2010-12. Urine test results for M. genitalium were available for 4507 participants aged 16-44 years reporting >1 lifetime sexual partner. In this study, we sequenced regions of the 23S rRNA and parC genes to detect known genotypic determinants for resistance to macrolides and fluoroquinolones respectively. RESULTS: 94% (66/70) of specimens were re-confirmed as M. genitalium positive, with successful sequencing in 85% (56/66) for 23S rRNA and 92% (61/66) for parC genes. Mutations in 23S rRNA gene (position A2058/A2059) were detected in 16.1% (95%CI: 8.6% to 27.8%) and in parC (encoding ParC D87N/D87Y) in 3.3% (0.9%-11.2%). Macrolide resistance was more likely in participants reporting STI diagnoses (past 5 years) (44.4% (18.9%-73.3%) vs 10.6% (4.6%-22.6%); p=0.029) or sexual health clinic attendance (past year) (43.8% (23.1%-66.8%) vs 5.0% (1.4%-16.5%); p=0.001). All 11 participants with AMR-conferring mutations had attended sexual health clinics (past 5 years), but none reported recent symptoms. CONCLUSIONS: This study highlights challenges in M. genitalium management and control. Macrolide resistance was present in one in six specimens from the general population in 2010-2012, but no participants with AMR M. genitalium reported symptoms. Given anticipated increases in diagnostic testing, new strategies including novel antimicrobials, AMR-guided therapy, and surveillance of AMR and treatment failure are recommended.

Highlighting the clinical need for diagnosing Mycoplasma genitalium infection.

Despite Mycoplasma genitalium (MG) being increasingly recognised as a genital pathogen in men and women, awareness and utility of commercially available MG-testing has been low. The opinion of UK sexual health clinicians and allied professionals was sought on how MG-testing should be used. Thirty-two consensus statements were developed by an expert group and circulated to clinicians and laboratory staff, who were asked to evaluate their level of agreement with each statement; 75% agreement was set as the threshold for defining consensus for each statement. A modified Delphi approach was used and high levels of agreement obviated the need to test the original statement set further. Of 201 individuals who received questionnaires, 60 responded, most (48) being sexual health consultants, more than 10% of the total in the UK. Twenty-seven (84.4%) of the statements exceeded the 75% threshold. Respondents strongly supported MG-testing of patients with urethritis, pelvic inflammatory disease or unexplained persistent vaginal discharge, or post-coital bleeding. Fewer favoured testing patients with proctitis and support was divided for routinely testing Chlamydia-positive patients. Testing of current sexual contacts of MG-positive patients was supported, as was a test of cure for MG-positive patients, although agreement fell below the 75% threshold. Respondents agreed that all consultant- or specialist-led services should have access to testing for MG (98.3%). There was strong agreement for having MG-testing available for specific patient groups, which may reflect concern over antibiotic resistance and the desire to comply with clinical guidelines that recommend MG-testing in sexual health clinic settings.

Trichomonas vaginalis infection is uncommon in the British general population: implications for clinical testing and public health screening.

INTRODUCTION: Variable use of new molecular assays, asymptomatic infections and a lack of population data mean that the population burden of Trichomonas vaginalis is uncertain. We investigated the age-specific prevalence of T. vaginalis within the sexually active British general population to inform testing strategies. METHODS: Britain's third National Survey of Sexual Attitudes and Lifestyle (Natsal-3) is a probability sample survey of 15 162 individuals aged 16-74 years, undertaken during 2010-2012. Urine from 4386 participants aged 16-44 years reporting ≥1 lifetime sexual partner was tested for T. vaginalis using in-house real-time PCR. RESULTS: Urinary T. vaginalis was detected in seven women and no men providing urine samples, giving a weighted prevalence estimate of 0.3% (95% CI 0.1% to 0.5%) in sexually experienced women aged 16-44 years. Of the seven women with T. vaginalis detected, four were of black or mixed ethnicity (prevalence 2.7% (0.9% to 7.7%) in this group) and five reported recent partners of black or mixed ethnicity. Six of the women reported symptoms, and five reported sexual health clinic attendance in the past 5 years (prevalence in those reporting clinic attendance: 1.0% (0.4% to 2.3%)). The prevalence of a self-reported history of T. vaginalis (past 5 years) was 0.1% (0.0% to 0.2%) in women and 0.0% (0.0% to 0.2%) in men aged 16-44 years. CONCLUSIONS: Our British population prevalence estimates indicate that T. vaginalis is a rare infection. These data support policies that restrict asymptomatic screening for T. vaginalis and suggest deployment of molecular tests should be focused within clinical settings and guided by symptoms and local demography.

Accurate detection of Neisseria gonorrhoeae ciprofloxacin susceptibility directly from genital and extragenital clinical samples: towards genotype-guided antimicrobial therapy.

INTRODUCTION: Increasing use of nucleic acid amplification tests (NAATs) as the primary means of diagnosing gonococcal infection has resulted in diminished availability of Neisseria gonorrhoeae antimicrobial susceptibility data. We conducted a prospective diagnostic assessment of a real-time PCR assay (NGSNP) enabling direct detection of gonococcal ciprofloxacin susceptibility from a range of clinical sample types. METHODS: NGSNP, designed to discriminate an SNP associated with ciprofloxacin resistance within the N. gonorrhoeae genome, was validated using a characterized panel of geographically diverse isolates (n = 90) and evaluated to predict ciprofloxacin susceptibility directly on N. gonorrhoeae-positive NAAT lysates derived from genital (n = 174) and non-genital (n = 116) samples (n = 290), from 222 culture-confirmed clinical episodes of gonococcal infection. RESULTS: NGSNP correctly genotyped all phenotypically susceptible (n = 49) and resistant (n = 41) panel isolates. Ciprofloxacin-resistant N. gonorrhoeae was responsible for infection in 29.7% (n = 66) of clinical episodes evaluated. Compared with phenotypic susceptibility testing, NGSNP demonstrated sensitivity and specificity of 95.8% (95% CI 91.5%-98.3%) and 100% (95% CI 94.7%-100%), respectively, for detecting ciprofloxacin-susceptible N. gonorrhoeae, with a positive predictive value of 100% (95% CI 97.7%-100%). Applied to urogenital (n = 164), rectal (n = 40) and pharyngeal samples alone (n = 30), positive predictive values were 100% (95% CI 96.8%-100%), 100% (95% CI 87.2%-100%) and 100% (95% CI 82.4%-100%), respectively. CONCLUSIONS: Genotypic prediction of N. gonorrhoeae ciprofloxacin susceptibility directly from clinical samples was highly accurate and, in the absence of culture, will facilitate use of tailored therapy for gonococcal infection, sparing use of current empirical treatment regimens and enhancing acquisition of susceptibility data for surveillance.

Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

BACKGROUND: In the context of widespread opportunistic chlamydia screening among young adults, we aimed to quantify chlamydia testing and diagnosis among 16-24 year olds in Britain in relation to risk factors for prevalent chlamydia infection. METHODS: Using data from sexually experienced (≥1 lifetime sexual partner) 16-year-old to 24-year-old participants in Britain's third National Survey of Sexual Attitudes and Lifestyles (conducted 2010-2012), we explored socio-demographic and behavioural factors associated with prevalent chlamydia infection (detected in urine; n=1832), self-reported testing and self-reported diagnosis in the last year (both n=3115). RESULTS: Chlamydia prevalence was 3.1% (95% CI 2.2% to 4.3%) in women and 2.3% (1.5% to 3.4%) in men. A total of 12.3% of women and 5.3% men had a previous chlamydia diagnosis. Factors associated with prevalent infection were also associated with testing and diagnosis (eg, increasing numbers of sexual partners), with some exceptions. For example, chlamydia prevalence was higher in women living in more deprived areas, whereas testing was not. In men, prevalence was higher in 20-24 than 16-19 year olds but testing was lower. Thirty per cent of women and 53.7% of men with ≥2 new sexual partners in the last year had not recently tested. CONCLUSIONS: In 2010-2012 in Britain, the proportion of young adults reporting chlamydia testing was generally higher in those reporting factors associated with chlamydia. However, many of those with risk factors had not been recently tested, leaving potential for undiagnosed infections. Greater screening and prevention efforts among individuals in deprived areas and those reporting risk factors for chlamydia may reduce undiagnosed prevalence and transmission.

Epidemiology of Mycoplasma genitalium in British men and women aged 16­44 years: evidence from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

BACKGROUND: There are currently no large general population epidemiological studies of Mycoplasma genitalium (MG), which include prevalence, risk factors, symptoms and co-infection in men and women across a broad age range. METHODS: In 2010-­12, we conducted the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a probability sample survey in Britain. Urine from 4507 sexually-experienced participants, aged 16­44 years, was tested for MG. RESULTS: MG prevalence was 1.2% [95% confidence interval (CI): 0.7­1.8%] in men and 1.3% (0.9­1.9%) in women. There were no positive MG tests in men aged 16­19, and prevalence peaked at 2.1% (1.2­3.7%) in men aged 25­34 years. In women, prevalence was highest in 16­19 year olds, at 2.4% (1.2­4.8%), and decreased with age. Men of Black ethnicity were more likely to test positive for MG [adjusted odds ratio (AOR) 12.1; 95% CI: 3.7­39.4). For both men and women, MG was strongly associated with reporting sexual risk behaviours (increasing number of total and new partners, and unsafe sex, in the past year). Women with MG were more likely to report post-coital bleeding (AOR 5.8; 95%CI 1.4­23.3). However, the majority of men (94.4%), and over half of women (56.2%) with MG did not report any sexually transmitted infection (STI) symptoms. Men with MG were more likely to report previously diagnosed gonorrhoea, syphilis or non-specific urethritis, and women previous trichomoniasis. CONCLUSIONS: This study strengthens evidence that MG is an STI. MG was identified in over 1% of the population, including in men with high-risk behaviours in older age groups that are often not included in STI prevention measures.

High-Risk Human Papillomavirus (HPV) Infection and Cervical Cancer Prevention in Britain: Evidence of Differential Uptake of Interventions from a Probability Survey.

BACKGROUND: The third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) provides an opportunity to explore high-risk human papillomavirus (HR-HPV) and uptake of cervical screening and HPV vaccination in the general population. METHODS: Natsal-3, a probability sample survey of men and women ages 16 to 74, resident in Britain, interviewed 8,869 women in 2010 to 2012. We explored risk factors for HR-HPV (in urine from 2,569 sexually experienced women ages 16 to 44), nonattendance for cervical screening in the past 5 years, and noncompletion of HPV catch-up vaccination. RESULTS: HR-HPV was associated with increasing numbers of lifetime partners, younger age, increasing area-level deprivation, and smoking. Screening nonattendance was associated with younger and older age, increasing area-level deprivation (age-adjusted OR 1.91, 95% confidence interval, 1.48-2.47 for living in most vs. least deprived two quintiles), Asian/Asian British ethnicity (1.96, 1.32-2.90), smoking (1.97, 1.57-2.47), and reporting no partner in the past 5 years (2.45, 1.67-3.61 vs. 1 partner) but not with HR-HPV (1.35, 0.79-2.31). Lower uptake of HPV catch-up vaccination was associated with increasing area-level deprivation, non-white ethnicity, smoking, and increasing lifetime partners. CONCLUSIONS: Socioeconomic markers and smoking were associated with HR-HPV positivity, nonattendance for cervical screening, and noncompletion of catch-up HPV vaccination. IMPACT: The cervical screening program needs to engage those missing HPV catch-up vaccination to avoid a potential widening of cervical cancer disparities in these cohorts. As some screening nonattenders are at low risk for HR-HPV, tailored approaches may be appropriate to increase screening among higher-risk women.

Frequency and correlates of culture-positive infection with Neisseria gonorrhoeae in England: a review of sentinel surveillance data.

OBJECTIVES: Reference laboratories are increasingly using more sensitive rapid molecular techniques, such as nucleic acid amplification tests (NAATs), to diagnose infections with Neisseria gonorrhoeae. We determined the proportion of patients at sentinel genitourinary medicine clinics in England whose NAAT-positive diagnoses were also culture-positive for N. gonorrhoeae, and investigated whether they differed from those that were not. METHODS: Behavioural and clinical data from all NAAT-positive patients reported from 23 clinics included in the Gonoccocal Resistance to Antimicrobials Surveillance Programme from July to September 2012 were included in this analysis. Unadjusted and adjusted associations between patient characteristics and culture-positive infection with N. gonorrhoeae were determined. RESULTS: Of 3076 NAAT-positive patients, 46.4% had culture-positive infections. Most NAAT-positive patients were <35 years old (73.0%), white (67.9%), and men who had sex with men (60.1%). Women and men who had sex with men were less likely than heterosexual men to have culture-positive infections (adjusted OR (95% CI) 0.53 (0.41 to 0.68), p<0.001; and 0.74 (0.59 to 0.93), p=0.010, respectively), while those who were symptomatic (4.61 (3.92 to 5.42), p<0.001), and those presenting with infection at multiple sites (2.15 (1.76 to 2.62), p<0.001) were more likely to have culture-positive infections. CONCLUSIONS: Although gonococcal isolates were available from almost half of the NAAT-positive patients, culture was not attempted or may have failed in the remainder. Patients with culture-positive isolates were not representative of all NAAT-positive patients. Routine culture is necessary for monitoring emerging antimicrobial resistance and to inform gonorrhoea treatment guidelines.

Can previous first-line therapies for Neisseria gonorrhoeae be targeted to specific patient subgroups to treat gonorrhea?

BACKGROUND: Gonorrhea treatment is challenging because of the emergence of resistance, treatment failure with existing drugs, and the lack of alternative agents. This study investigates the feasibility of targeting previously recommended antimicrobials to specific population subgroups where the prevalence of infection susceptible to these antimicrobials is above the World Health Organization cautionary treatment threshold of 95%. METHODS: Descriptive data from the Gonococcal Resistance to Antimicrobials Surveillance Programme for England and Wales were analyzed to investigate patient characteristics associated with infection with susceptible isolates using univariate and multivariable analyses. RESULTS: Of 6173 isolates from 2007 to 2011, 4684 (82%) were susceptible to penicillin, 3899 (68%) to ciprofloxacin, and 5240 (91%) to cefixime. All subgroups of the MSM population had fewer than 95% of isolates susceptible to penicillin, ciprofloxacin, or cefixime. Higher proportions of isolates from heterosexual patient subgroups were susceptible to these antimicrobials. Multivariable models identified the following associations between patient characteristics and infection with susceptible isolates: patients aged 13 to 24 years (penicillin: 92.3% susceptible adjusted odds ratio and associated 95% confidence interval [aOR CI] 1.84-2.97; ciprofloxacin: 88.3%, aOR CI 2.22-3.39; cefixime: 98.7%, aOR CI 1.29-3.52) patients of black ethnicity (penicillin: 93.9%, aOR CI 2.72-4.91; ciprofloxacin: 92.0%, aOR CI 3.94-6.7; cefixime: 99.1%, aOR CI 1.78-6.4), and patients with concurrent chlamydia (penicillin: 93.9%, aOR CI 1.8-3.22; ciprofloxacin: 91.7%, aOR CI 2.71-4.58; cefixime: 99.0%, aOR CI 1.27-4.54). CONCLUSIONS: This study demonstrated that of the previous first-line therapies, cefixime would be the only antimicrobial suitable for use for infection in heterosexual patients alone.

Confirmatory assays are essential when using molecular testing for Neisseria gonorrhoeae in low-prevalence settings: insights from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

OBJECTIVES: To investigate the occurrence of unconfirmed positive gonorrhoea results when using molecular testing within a large population-based survey. DESIGN, SETTING AND PARTICIPANTS: Between 2010 and 2012, we did a probability sample survey of 15,162 men and women aged 16-74 years in Britain. Urine from participants aged 16-44 years reporting ≥1 lifetime sexual partner was tested for Neisseria gonorrhoeae and Chlamydia trachomatis using the Aptima Combo 2 (AC2) assay, with positive or equivocal results confirmed with molecular assays using different nucleic acid targets. RESULTS: A total of 4550 participants aged 16-44 years had urine test results (1885 men; 2665 women). For gonorrhoea, 18 samples initially tested positive and eight were equivocal. Only five out of 26 confirmed, giving a positive predictive value (PPV) for the initial testing of 19% (95% CI 4% to 34%). Most (86% (18/21)) participants with unconfirmed positive results for gonorrhoea reported zero or one sexual partner without condoms in the past year and none had chlamydia co-infection, whereas all five with confirmed gonorrhoea reported at least two recent sexual partners without condoms, and four had chlamydia co-infection. The weighted prevalence for gonorrhoea positivity fell from 0.4% (0.3% to 0.7%) after initial screening to <0.1% (0.0% to 0.1%) after confirmatory testing. By comparison, 103 samples tested positive or equivocal for chlamydia and 98 were confirmed (PPV=95% (91% to 99%)). CONCLUSIONS: We highlight the low PPV for gonorrhoea of an unconfirmed reactive test when deploying molecular testing in a low-prevalence population. Failure to undertake confirmatory testing in low-prevalence settings may lead to inappropriate diagnoses, unnecessary treatment and overestimation of population prevalence.

Screening for gonorrhoea using samples collected through the English national chlamydia screening programme and risk of false positives: a national survey of local authorities.

OBJECTIVES: To investigate use of dual tests for Chlamydia trachomatis and Neisseria gonorrhoeae on samples collected through the National Chlamydia Screening Programme (NCSP) in England. DESIGN AND SETTING: During May-July 2013, we delivered an online survey to commissioners of sexual health services in the 152 upper-tier English Local Authorities (LAs) who were responsible for commissioning chlamydia screening in people aged 15-24 years. MAIN OUTCOME MEASURES: (1) The proportion of English LAs using dual tests on samples collected by the NCSP; (2) The estimated number of gonorrhoea tests and false positives from samples collected by the NCSP, calculated using national surveillance data on the number of chlamydia tests performed, assuming the gonorrhoea prevalence to range between 0.1% and 1%, and test sensitivity and specificity of 99.5%. RESULTS: 64% (98/152) of LAs responded to this national survey; over half (53% (52/98)) reported currently using dual tests in community settings. There was no significant difference between LAs using and not using dual tests by chlamydia positivity, chlamydia diagnosis rate or population screening coverage. Although positive gonorrhoea results were confirmed with supplementary tests in 93% (38/41) of LAs, this occurred after patients were notified about the initial positive result in 63% (26/41). Approximately 450-4500 confirmed gonorrhoea diagnoses and 2300 false-positive screens might occur through use of dual tests on NCSP samples each year. Under reasonable assumptions, the positive predictive value of the screening test is 17-67%. CONCLUSIONS: Over half of English LAs already commission dual tests for samples collected by the NCSP. Gonorrhoea screening has been introduced alongside chlamydia screening in many low prevalence settings without a national evidence review or change of policy. We question the public health benefit here, and suggest that robust testing algorithms and clinical management pathways, together with rigorous evaluation, be implemented wherever dual tests are deployed.

An evaluation of Neisseria gonorrhoeae antimicrobial susceptibility testing in the UK.

The only method currently available to perform Neisseria gonorrhoeae antimicrobial susceptibility testing (Ng-AST) requires a viable organism obtained by culture. Reports of in vitro resistance to extended-spectrum cephalosporins, the treatment of choice for gonorrhoea, coupled with increasing gonorrhoea diagnoses is worrying. The aim of this study was to identify various methodologies employed by the UK microbiology laboratories to perform Ng-AST. Of the 118 laboratories that responded, 114 offered Ng-AST; the majority (82.5%, 94/114) of the laboratories used British Society for Antimicrobial Chemotherapy methodology for Ng-AST. The other main findings were infrequent use of quality control procedures and inconsistent susceptibility testing of the antibiotics used routinely for treatment.

Nucleic acid amplification tests for the diagnosis of Neisseria gonorrhoeae in low-prevalence settings: a review of the evidence.

OBJECTIVES: In UK Microbiology laboratories there is widespread use of nucleic acid amplification tests (NAATs) which allow the simultaneous 'dual' detection of Neisseria gonorrhoeae and Chlamydia trachomatis, although the prevalence of gonorrhoea in most areas is low and this may lead to high numbers of false positive results. The aim of this study was to examine the evidence base for unselected testing for gonorrhoea in the community. METHODS: A literature search was performed to review the use of dual testing in low prevalence settings by searching PubMed for appropriate terms linked to gonorrhoea diagnosis up to 1 December 2013 but without restriction of publication date. All publications with a prevalence of <1% were defined as low prevalence and included in this review. RESULTS: The publication search found data in low prevalence settings from three sources; genitourinary medicine clinics, laboratories outside the UK and from the National Chlamydia Screening Programme. The evidence base to support widespread screening for gonorrhoea was found to be limited and of variable quality. CONCLUSIONS: We were unable to find an evidence base to support widespread screening for gonorrhoea in the community. However, the increasing availability of dual NAATs may lead to more testing but this should be tempered by the public health need. Pilot studies and development of robust testing algorithms should be encouraged.

Evaluation of the activity of ertapenem against gonococcal isolates exhibiting a range of susceptibilities to cefixime.

OBJECTIVES: There is a need for new or alternative antimicrobial agents for the treatment of gonorrhoea as antimicrobial resistance emerges to current therapies. The aim was to investigate the activity of ertapenem against isolates of Neisseria gonorrhoeae with decreased susceptibility to cefixime. METHODS: A panel of 52 clinical isolates and 10 control strains of N. gonorrhoeae were selected to represent a range of susceptibilities to cefixime. Susceptibility testing was performed using the methodology used for the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP). The isolates were typed by N. gonorrhoeae multi-antigen sequence typing (NG-MAST). RESULTS: The isolates comprised 42 different molecular types as defined by NG-MAST. The susceptibility of the clinical isolates to ertapenem was similar to that of cefixime, with a Pearson's correlation coefficient of R = 0.89. The MIC90 and MIC50 values of ertapenem were 0.25 and 0.12 mg/L, respectively, while those of cefixime were 0.12 and 0.06 mg/L, respectively. However, these isolates were more susceptible to ceftriaxone than ertapenem, with a Pearson's correlation coefficient of R = 0.65 and ceftriaxone MIC90 and MIC50 values of 0.03 and 0.016 mg/L, respectively. The isolates that were least susceptible to ertapenem were all non-producers of penicillinase. However, one isolate that was highly resistant to cefixime and ceftriaxone was more susceptible to ertapenem than either cefixime or ceftriaxone. CONCLUSIONS: This study has shown that ertapenem is not a suitable alternative for first-line treatment for gonorrhoea but that it may be useful for the treatment of highly resistant infections.