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.

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.

Whole-genome sequences of Chlamydia trachomatis directly from clinical samples without culture.

The use of whole-genome sequencing as a tool for the study of infectious bacteria is of growing clinical interest. Chlamydia trachomatis is responsible for sexually transmitted infections and the blinding disease trachoma, which affect hundreds of millions of people worldwide. Recombination is widespread within the genome of C. trachomatis, thus whole-genome sequencing is necessary to understand the evolution, diversity, and epidemiology of this pathogen. Culture of C. trachomatis has, until now, been a prerequisite to obtain DNA for whole-genome sequencing; however, as C. trachomatis is an obligate intracellular pathogen, this procedure is technically demanding and time consuming. Discarded clinical samples represent a large resource for sequencing the genomes of pathogens, yet clinical swabs frequently contain very low levels of C. trachomatis DNA and large amounts of contaminating microbial and human DNA. To determine whether it is possible to obtain whole-genome sequences from bacteria without the need for culture, we have devised an approach that combines immunomagnetic separation (IMS) for targeted bacterial enrichment with multiple displacement amplification (MDA) for whole-genome amplification. Using IMS-MDA in conjunction with high-throughput multiplexed Illumina sequencing, we have produced the first whole bacterial genome sequences direct from clinical samples. We also show that this method can be used to generate genome data from nonviable archived samples. This method will prove a useful tool in answering questions relating to the biology of many difficult-to-culture or fastidious bacteria of clinical concern.

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.

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.

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.

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.

Prevalence, risk factors, and uptake of interventions for sexually transmitted infections in Britain: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal).

BACKGROUND: Population-based estimates of prevalence, risk distribution, and intervention uptake inform delivery of control programmes for sexually transmitted infections (STIs). We undertook the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) after implementation of national sexual health strategies, and describe the epidemiology of four STIs in Britain (England, Scotland, and Wales) and the uptake of interventions. METHODS: Between Sept 6, 2010 and Aug 31, 2012, we did a probability sample survey of 15,162 women and men aged 16-74 years in Britain. Participants were interviewed with computer-assisted face-to-face and self-completion questionnaires. Urine from a sample of participants aged 16-44 years who reported at least one sexual partner over the lifetime was tested for the presence of Chlamydia trachomatis, type-specific human papillomavirus (HPV), Neisseria gonorrhoeae, and HIV antibody. We describe age-specific and sex-specific prevalences of infection and intervention uptake, in relation to demographic and behavioural factors, and explore changes since Natsal-1 (1990-91) and Natsal-2 (1999-2001). FINDINGS: Of 8047 eligible participants invited to provide a urine sample, 4828 (60%) agreed. We excluded 278 samples, leaving 4550 (94%) participants with STI test results. Chlamydia prevalence was 1·5% (95% CI 1·1-2·0) in women and 1·1% (0·7-1·6) in men. Prevalences in individuals aged 16-24 years were 3·1% (2·2-4·3) in women and 2·3% (1·5-3·4) in men. Area-level deprivation and higher numbers of partners, especially without use of condoms, were risk factors. However, 60·4% (45·5-73·7) of chlamydia in women and 43·3% (25·9-62·5) in men was in individuals who had had one partner in the past year. Among sexually active 16-24-year-olds, 54·2% (51·4-56·9) of women and 34·6% (31·8-37·4) of men reported testing for chlamydia in the past year, with testing higher in those with more partners. High-risk HPV was detected in 15·9% (14·4-17·5) of women, similar to in Natsal-2. Coverage of HPV catch-up vaccination was 61·5% (58·2-64·7). Prevalence of HPV types 16 and 18 in women aged 18-20 years was lower in Natsal-3 than Natsal-2 (5·8% [3·9-8·6] vs 11·3% [6·8-18·2]; age-adjusted odds ratio 0·44 [0·21-0·94]). Gonorrhoea (<0·1% prevalence in women and men) and HIV (0·1% prevalence in women and 0·2% in men) were uncommon and restricted to participants with recognised high-risk factors. Since Natsal-2, substantial increases were noted in attendance at sexual health clinics (from 6·7% to 21·4% in women and from 7·7% to 19·6% in men) and HIV testing (from 8·7% to 27·6% in women and from 9·2% to 16·9% in men) in the past 5 years. INTERPRETATION: STIs were distributed heterogeneously, requiring general and infection-specific interventions. Increases in testing and attendance at sexual health clinics, especially in people at highest risk, are encouraging. However, STIs persist both in individuals accessing and those not accessing services. Our findings provide empirical evidence to inform future sexual health interventions and services. FUNDING: Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and the Department of Health.

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.

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.

Risk factors for antimicrobial-resistant Neisseria gonorrhoeae in Europe.

BACKGROUND: The European Gonococcal Antimicrobial Surveillance Programme performs antimicrobial resistance surveillance and is coordinated by the European Centre for Disease Prevention and Control. This study used epidemiological and behavioral data combined with the gonococcal susceptibility profiles to determine risk factors associated with harboring resistant gonococci in Europe. METHODS: From 2009 to 2011, gonococcal isolates from 21 countries were submitted to the European Gonococcal Antimicrobial Surveillance Programme for antimicrobial susceptibility testing. Patient variables associated with resistance to azithromycin, cefixime, and ciprofloxacin were identified using univariate and multivariable logistic regression analyses of odds ratios. Geometric means for ceftriaxone and cefixime minimum inhibitory concentrations (MICs) were compared for patients of different sexual orientation and sex. RESULTS: A total of 5034 gonococcal isolates were tested from 2009 to 2011. Isolates exhibiting resistance to cefixime (MIC > 0.125 mg/L) and ciprofloxacin (MIC > 0.5 mg/L) were significantly associated with infection in heterosexuals (males only for ciprofloxacin), older patients (>25 years of age), or those without a concurrent chlamydial infection in the multivariable analysis. The geometric mean of cefixime and ceftriaxone MICs decreased from 2009 to 2011, most significantly for men who have sex with men, and isolates from male heterosexuals exhibited the highest MICs in 2011. CONCLUSIONS: The linking of epidemiological and behavioral data to the susceptibility profiles of the gonococcal isolates has allowed those at higher risk for acquiring antimicrobial resistant Neisseria gonorrhoeae to be identified. Improved data numbers and representativeness are required before evidence-based risk groups can be identified, and subsequent focused treatments or public health intervention strategies can be initiated with confidence.

Combination therapy for gonorrhoea: in vitro synergy testing.

OBJECTIVES: Antimicrobial resistance in Neisseria gonorrhoeae is an increasing problem worldwide and combinations of antimicrobial agents have been recommended to delay the onset of treatment failures. The objective of this study was to obtain in vitro data on the activity of current (ceftriaxone or cefixime plus azithromycin) and alternative (gentamicin plus azithromycin) regimens. METHODS: A panel of 64 gonococcal isolates displaying various cefixime MICs was selected for inclusion in the study. Determination of the activities of the antimicrobial combinations of ceftriaxone, cefixime or gentamicin with azithromycin was performed using the agar dilution method and subsequent calculation of the fractional inhibitory concentration index (FICI) values. RESULTS: No antagonism for any of the antimicrobial combinations was detected among the 64 gonococcal isolates. When cefixime or ceftriaxone was combined with azithromycin all isolates showed additivity/indifference with a mean FICI of 2.0. All gonococcal isolates also showed additivity/indifference with the antimicrobial combination of gentamicin with azithromycin, but with a lower mean FICI of 1.7. No significant difference in the mean FICI between isolates fully susceptible to cefixime and isolates with decreased susceptibility to cefixime was observed. CONCLUSIONS: The results obtained support the gonorrhoea treatment currently recommended in the UK national guidelines and suggest that gentamicin with azithromycin could be a future treatment option. The in vivo activity and efficacy of these combinations remain unknown and prospective clinical studies should be addressed.

Current and future treatment options for gonorrhoea.

The delivery of effective antimicrobial therapy is essential for public health control of gonorrhoea, in the absence of a suitable vaccine. The antimicrobial agent chosen should have high efficacy and quality, lack toxicity and give >95% success when given empirically. Guidelines, which are informed by surveillance data, are used to aid clinicians in their choice of appropriate agent. Historically, gonorrhoea treatment has been delivered as a single, directly observed dose but this has resulted in failure of successive antimicrobial agents which have been replaced by a new antimicrobial to which resistance has been rare or non-existing. Following the drift towards decreased susceptibility and treatment failure to the extended spectrum cephalosporins, and the lack of 'new' alternative antimicrobials, the threat of difficult to treat or untreatable gonorrhoea has emerged. The challenge of maintaining gonorrhoea as a treatable infection has resulted in national, regional and global response or action plans. This review discusses different approaches to the future treatment of gonorrhoea including; use of ceftriaxone, the injectable cephalosporin at increased dosage; dual antimicrobial therapy; use of drugs developed for other infections and use of older agents, directed by rapid point of care tests, to susceptible infections. Finally, it is considered whether the time is right to readdress the possibility of developing an effective gonococcal vaccine, given the major advances in our understanding of natural infection, molecular pathogenesis and the revolution in molecular biology techniques.

Evolution of Neisseria gonorrhoeae is a continuing challenge for molecular detection of gonorrhoea: false negative gonococcal porA mutants are spreading internationally.

OBJECTIVES: Identification of genetic targets specific to Neisseria gonorrhoeae for use in molecular detection methods has been a challenge. The porA pseudogene in N gonorrhoeae has been commonly used but recently gonococcal isolates giving a negative result in these PCRs have been reported. Here we describe the characterisation of two such gonococcal isolates received by the reference service at the Health Protection Agency, London, England. METHODS: Phenotypic characterisation was achieved using conventional biochemical and immunological tests, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), antimicrobial susceptibility testing, serovar determination and detection of meningococcal PorA using monoclonal antibody 4BG4-E7. Genetic species confirmation was determined using commercial and in house PCRs and 16S rRNA gene sequencing. Molecular typing using the N gonorrhoeae multi-antigen sequence typing (NG-MAST) and multilocus sequence typing (MLST) was performed. The DNA sequence of the full-length gonococcal porA pseudogene was determined and compared with published sequences. RESULTS: Both isolates were confirmed, biochemically and immunologically as N gonorrhoeae, but repeatedly gave negative results with two in house real-time PCR assays for the porA pseudogene. Further characterisation of these isolates identified the presence of a meningococcal porA sequence and showed these isolates belong to serovar Bropyst, and to NG-MAST sequence type (ST) 5967 and MLST ST1901. CONCLUSIONS: Gonococcal isolates that give false negative results with porA pseudogene PCR assays have now been identified in four countries, three of which are in Europe, and do not appear clonal. This report highlights the genetic diversity of N gonorrhoeae, which remains a challenge for the molecular detection methods.

Gonorrhoea and gonococcal antimicrobial resistance surveillance networks in the WHO European Region, including the independent countries of the former Soviet Union.

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae has emerged for essentially all antimicrobials following their introduction into clinical practice. During the latest decade, susceptibility to the last remaining options for antimicrobial monotherapy, the extended-spectrum cephalosporins (ESC), has markedly decreased internationally and treatment failures with these ESCs have been verified. In response to this developing situation, WHO and the European Centre for Disease Prevention and Control (ECDC) have published global and region-specific response plans, respectively. One main component of these action/response plans is to enhance the surveillance of AMR and treatment failures. This paper describes the perspectives from the diverse WHO European Region (53 countries), including the independent countries of the former Soviet Union, regarding gonococcal AMR surveillance networks. The WHO European Region has a high prevalence of resistance to all previously recommended antimicrobials, and most of the first strictly verified treatment failures with cefixime and ceftriaxone were also reported from Europe. In the European Union/European Economic Area (EU/EEA), the European gonococcal antimicrobial surveillance programme (Euro-GASP) funded by the ECDC is running. In 2011, the Euro-GASP included 21/31 (68%) EU/EEA countries, and the programme is further strengthened annually. However, in the non-EU/EEA countries, internationally reported and quality assured gonococcal AMR data are lacking in 87% of the countries and, worryingly, appropriate support for establishment of a GASP is still lacking. Accordingly, national and international support, including political and financial commitment, for gonococcal AMR surveillance in the non-EU/EEA countries of the WHO European Region is essential.

Molecular epidemiology of gonorrhoea in Wales (UK).

OBJECTIVES: After a trend of increasing incidence of gonorrhoea in the 1990s, by 2004 the incidence was declining in England, but continuing to increase in Wales. This prompted an investigation of the epidemiology of gonorrhoea in Wales to inform future prevention and control measures. METHODS: As an extension to Gonococcal Resistance to Antimicrobials Surveillance Programme, between May 2005 and September 2006, 540 consecutive gonococcal isolates were collected from three microbiology laboratories in South Wales. Isolates were typed using Neisseria gonorrhoeae Multi Antigen Sequence Typing tested for susceptibility to therapeutic agents and demographic and behavioural data were collected retrospectively from patient notes. RESULTS: 163 sequence types (STs) were identified in 475 N gonorrhoeae isolates from 502 patient episodes. The most frequently observed STs (>20 isolates) were: 2, 752, 471, 249 and 8, all of which were susceptible to the antimicrobial agents tested. A significant association between ST and sexual orientation was identified, the most frequently observed STs occurring in young (median age <25 years) heterosexuals. STs 147, 4, 1634 and 64 predominated in men who have sex with men. CONCLUSIONS: We confirm the existence of common STs across the UK, as well as identify a number of types that were novel to Wales. Discrete sexual networks were identified, the most localised being in young heterosexuals. Molecular typing provides a method for identifying local clusters of gonorrhoea, and could assist in the implementation and evaluation of targeted interventions.

Antimicrobial resistance in sexually transmitted infections in the developed world: implications for rational treatment.

PURPOSE OF REVIEW: Public health control of bacterial sexually transmitted infections (STIs) is dependent on the delivery of effective therapy and so will be compromised by the emergence of resistance. The scope of the problem and the implications for treatment that follow are discussed in this review. RECENT FINDINGS: Emerging resistance has been documented in all the bacterial STIs, but is considered rare and unconfirmed in Chlamydia trachomatis whereas is of global concern in Neisseria gonorrhoeae. Azithromycin resistance has now been recognized in Mycoplasma genitalium, Treponema pallidum and N. gonorrhoeae, questioning its widespread use for chlamydial infection and threatening its future use. Rapidly increasing levels of decreased susceptibility to the extended-spectrum cephalosporins in N. gonorrhoeae and emerging treatment failures to both cefixime and ceftriaxone, without an obvious alternative agent, are of considerable concern. Implications for treatment include choice and timing of any change in therapy, reintroduction of test of cure and definition of treatment failure in an era of molecular testing. SUMMARY: Emerging resistance in all bacterial STIs and the particular problem of resistant gonorrhoea will present a challenge to maintain antimicrobial therapy at the forefront of public health control.