Cathy Ison

The molecular diagnosis of lymphogranuloma venereum: evaluation of a real-time multiplex polymerase chain reaction test using rectal and urethral specimens.

Objectives: The objectives of this study were to evaluate the use of a real-time multiplex polymerase chain reaction (M-PCR) assay to differentiate between trachoma and lymphogranuloma venereum (LGV) biovars of Chlamydia trachomatis and to validate its performance with the conventional genotyping method. Study: Swab specimens from 115 patients with anorectal symptoms or syndromes associated with LGV were tested by a real-time M-PCR assay and the results compared with the PCR-based restriction fragment length polymorphism analysis of the major outer membrane protein gene (omp1). Results: A high agreement of 96.5% (111 of 115 specimens) was found between the real-time M-PCR testing and the standard genotyping method for the detection of C. trachomatis DNA (&kgr; value, 0.945, P <0.00001). Both methods identified 53 LGV, 32 non-LGV C. trachomatis, and 26 negative specimens. Conclusions: The real-time M-PCR assay simultaneously detects and differentiates LGV from non-LGV strains using swab specimens. This assay offers a relatively rapid and sensitive alternative for the diagnosis of LGV infection and is a useful tool for screening and for outbreak investigations.

Lymphogranuloma venereum in the United Kingdom

First cases reported from enhanced surveillancennUntil 2003 lymphogranuloma venereum (LGV), a disease caused by the more invasive L serovars of Chlamydia trachomatis , was considered a rare disease outside resource poor countries. Since then it has emerged as a significant problem among men who have sex with men (MSM) in Europe. In 2003 an outbreak of LGV was recognised in Rotterdam in the Netherlands.1 More than 100 men have been reported in this outbreak, most of whom were HIV positive and many had concomitant sexually transmitted infections including hepatitis C infection. Although many reported unprotected anal sex as a risk factor for acquisition of LGV, fisting and the sharing of sex toys also appeared as possible routes of transmission. Almost all presented with proctitis and symptoms included rectal pain, discharge, tenesmus, and other signs of lower gastrointestinal inflammation including constipation and abdominal pain. Some reported systemic symptoms such as fever and malaise. Genital and inguinal symptoms were rare with only one patient presenting with inguinal lymphadenopathy.nnSince that report similar outbreaks have been …

Microscopy outperformed in a comparison of five methods for detecting Trichomonas vaginalis in symptomatic women

In the UK, despite its low sensitivity, wet mount microscopy is often the only method of detecting Trichomonas vaginalis infection. A study was conducted in symptomatic women to compare the performance of five methods for detecting T. vaginalis: an in-house polymerase chain reaction (PCR); Aptima T. vaginalis kit; OSOM ®Trichomonas Rapid Test; culture and microscopy. Symptomatic women underwent routine testing; microscopy and further swabs were taken for molecular testing, OSOM and culture. A true positive was defined as a sample that was positive for T. vaginalis by two or more different methods. Two hundred and forty-six women were recruited: 24 patients were positive for T. vaginalis by two or more different methods. Of these 24 patients, 21 patients were detected by real-time PCR (sensitivity 88%); 22 patients were detected by the Aptima T. vaginalis kit (sensitivity 92%); 22 patients were detected by OSOM (sensitivity 92%); nine were detected by wet mount microscopy (sensitivity 38%); and 21 were detected by culture (sensitivity 88%). Two patients were positive by just one method and were not considered true positives. All the other detection methods had a sensitivity to detect T. vaginalis that was significantly greater than wet mount microscopy, highlighting the number of cases that are routinely missed even in symptomatic women if microscopy is the only diagnostic method available.

United Kingdom National Guideline on the Management of Trichomonas vaginalis 2014

The main objective is to assist practitioners in managing men and women diagnosed with Trichomonas vaginalis (TV) infection. This guideline offers recommendations on the diagnostic tests, treatment regimens and health promotion principles needed for the effective management of TV, covering the management of the initial presentation, as well as how to prevent transmission and future infection.

Risk factors for rectal lymphogranuloma venereum in gay men: results of a multicentre case-control study in the UK

Objective To identify risk factors for rectal lymphogranuloma venereum (rLGV) in men who have sex with men (MSM). Design A case-control study at 6 UK hospitals compared MSM with rLGV (cases) with rLGV-negative controls: MSM without potential rLGV symptoms (CGa) and separately, MSM with such symptoms (CGs). Methods Between 2008 and 2010, there were 90 rLGV cases, 74 CGa and 69 CGs recruited. Lifestyles and sexual behaviours in the previous 3u2005months were reported using internet-based computer-assisted self-interviews. Logistic regression was used to investigate factors associated with rLGV. Results Cases were significantly more likely to be HIV-positive (89%) compared with CGa (46%) and CGs (64%). Independent behavioural risks for rLGV were: unprotected receptive anal intercourse (adjusted OR (AOR)10.7, 95% CI 3.5 to 32.8), fisting another (AOR=6.7, CI 1.8 to 25.3), sex under the influence of gamma-hydroxybutyrate (AOR=3.1, CI 1.3 to 7.4) and anonymous sexual contacts (AOR=2.7, CI 1.2 to 6.3), compared with CGa; unprotected insertive anal intercourse (AOR=4.7, CI 2.0 to 10.9) and rectal douching (AOR=2.9 CI 1.3 to 6.6), compared with CGs. An incubation period from exposure to symptoms of 30u2005days was indicated. Conclusions Unprotected receptive anal intercourse is a key risk factor for rectal LGV with the likelihood that rectal-to-rectal transmission is facilitated where insertive anal sex also occurs. The association between HIV and rLGV appears linked to HIV-positive men seeking unprotected sex with others with the same HIV status, sexual and drug interests. Such men should be targeted for frequent STI screening and interventions to minimise associated risks.

Comprehensive global genome dynamics of Chlamydia trachomatis show ancient diversification followed by contemporary mixing and recent lineage expansion

Chlamydia trachomatis is the worlds most prevalent bacterial sexually transmitted infection and leading infectious cause of blindness, yet it is one of the least understood human pathogens, in part due to the difficulties of in vitro culturing and the lack of available tools for genetic manipulation. Genome sequencing has reinvigorated this field, shedding light on the contemporary history of this pathogen. Here, we analyze 563 full genomes, 455 of which are novel, to show that the history of the species comprises two phases, and conclude that the currently circulating lineages are the result of evolution in different genomic ecotypes. Temporal analysis indicates these lineages have recently expanded in the space of thousands of years, rather than the millions of years as previously thought, a finding that dramatically changes our understanding of this pathogens history. Finally, at a time when almost every pathogen is becoming increasingly resistant to antimicrobials, we show that there is no evidence of circulating genomic resistance in C. trachomatis.

Clinical predictors of rectal lymphogranuloma venereum infection: results from a multicentre case–control study in the UK

Objective Since 2003, over 2000 cases of lymphogranuloma venereum (LGV) have been diagnosed in the UK in men who have sex with men (MSM). Most cases present with proctitis, but there are limited data on how to differentiate clinically between LGV and other pathology. We analysed the clinical presentations of rectal LGV in MSM to identify clinical characteristics predictive of LGV proctitis and produced a clinical prediction model. Design A prospective multicentre case–control study was conducted at six UK hospitals from 2008 to 2010. Cases of rectal LGV were compared with controls with rectal symptoms but without LGV. Methods Data from 98 LGV cases and 81 controls were collected from patients and clinicians using computer-assisted self-interviews and clinical report forms. Univariate and multivariate logistic regression was used to compare symptoms and signs. Clinical prediction models for LGV were compared using receiver operating curves. Results Tenesmus, constipation, anal discharge and weight loss were significantly more common in cases than controls. In multivariate analysis, tenesmus and constipation alone were suggestive of LGV (OR 2.98, 95% CI 0.99 to 8.98 and 2.87, 95% CI 1.01 to 8.15, respectively) and that tenesmus alone or in combination with constipation was a significant predictor of LGV (OR 6.97, 95% CI 2.71 to 17.92). The best clinical prediction was having one or more of tenesmus, constipation and exudate on proctoscopy, with a sensitivity of 77% and specificity of 65%. Conclusions This study indicates that tenesmus alone or in combination with constipation makes a diagnosis of LGV in MSM presenting with rectal symptoms more likely.

How to do it: lessons identified from investigating and trying to control an outbreak of gonorrhoea in young heterosexual adults

In the early summer of 2011, clinicians at Northumberland Sexual Health clinic noticed a sustained increase in cases of gonorrhoea and, more noticeably, a change in case profile from the usual picture of predominantly men who have sex with men (MSM) to heterosexual young adults, with more young females affected. The lead clinician contacted the local Health Protection Team (HPT) to seek advice about investigation and public health interventions. A multiagency outbreak control team (OCT) was convened to coordinate the investigation and control measures.nnOver the following 3-year period, 360 cases of gonorrhoea were detected in a locally discrete population (figure 1) affecting mainly young heterosexual adults. Patterns of transmission were studied and control measures implemented; however, cases continued to occur at rates higher than pre-outbreak levels.nnnnFigurexa01 nEpidemic curve of outbreak showing all gonorrhoea cases resident in Northumberland, January 2010 to November 2014, including dates when outbreak control actions were initiated. *2010 data were extracted from GUMCAD, 2011 onwards were from enhanced surveillance.nnnnWe describe the approaches taken for investigation and implementation of control measures, reflect on lessons learned and offer advice to colleagues facing similar situations. Figurexa01 describes the actions taken over the course of the outbreak investigation.nnCases were managed according to UK national standards.1 Almost all cases were treated on the day of diagnosis. All patients were advised to return for a test of cure; 50% did and all were negative. Eighty-five per cent of cases were treated with ceftriaxone and azithromycin. All cases were offered a full sexually transmitted infection (STI)/HIV screen; 97% accepted. The main reason for declining a full STI screen was not wishing to have a blood sample collected.nnGuidance on the investigation and management of outbreaks of STIs, including the different teams and organisations that should be included, is available2 …

Can we use postal surveys with anonymous testing to monitor chlamydia prevalence in young women in England? Pilot study incorporating randomised controlled trial of recruitment methods

Objectives Chlamydia prevalence in the general population is a potential outcome measure for the evaluation of chlamydia control programmes. We carried out a pilot study to determine the feasibility of using a postal survey for population-based chlamydia prevalence monitoring. Methods Postal invitations were sent to a random sample of 2000 17-year-old to 18-year-old women registered with a general practitioner in two pilot areas in England. Recipients were randomised to receive either a self-sampling kit (n=1000), a self-sampling kit and offer of £5 voucher on return of sample (n=500) or a self-sampling kit on request (n=500). Participants returned a questionnaire and self-taken vulvovaginal swab sample for unlinked anonymous Chlamydia trachomatis testing. Non-responders were sent a reminder letter 3u2005weeks after initial invitation. We calculated the participation rate (number of samples returned/number of invitations sent) and cost per sample returned (including cost of consumables and postage) in each group. Results A total of 155/2000 (7.8%) samples were returned with consent for testing. Participation rates varied by invitation group: 7.8% in the group who were provided with a self-sampling kit, 14% in the group who were also offered a voucher and 1.0% in the group who were not sent a kit. The cost per sample received was lowest (£36) in the group who were offered both a kit and a voucher. Conclusions The piloted survey methodology achieved low participation rates. This approach is not suitable for population-based monitoring of chlamydia prevalence among young women in England. Study registration number (UKCRN ID 10913).

Prevalence and characteristics of gastrointestinal infections in men who have sex with men diagnosed with rectal chlamydia infection in the UK: an ‘unlinked anonymous’ cross-sectional study

Introduction Gastrointestinal infections (GII) can cause serious ill health and morbidity. Although primarily transmitted through faecal contamination of food or water, transmission through sexual activity is well described, especially among men who have sex with men (MSM). Methods We investigated the prevalence of GIIs among a convenience sample of MSM who were consecutively diagnosed with rectal Chlamydia trachomatis (CT) at 12 UK genitourinary medicine clinics during 10u2005weeks in 2012. Residual rectal swabs were coded, anonymised and tested for Shigella, Campylobacter, Salmonella, shiga toxin-producing Escherichia coli and enteroaggregative E. coli (EAEC) using a real-time PCR. Results were linked to respective coded and anonymised clinical and demographic data. Associations were investigated using Fishers exact tests. Results Of 444 specimens tested, overall GII prevalence was 8.6% (95% CI 6.3% to 11.6%): 1.8% (0.9% to 3.6%) tested positive for Shigella, 1.8% (0.9% to 3.6%) for Campylobacter and 5.2% (3.5% to 7.7%) for EAEC. No specimens tested positive for Salmonella or other diarrhoeagenic E. coli pathotypes. Among those with any GII, 14/30 were asymptomatic (2/7 with Shigella, 3/6 with Campylobacter and 9/17 with EAEC). Shigella prevalence was higher in MSM who were HIV-positive (4.7% (2.1% to 10.2%) vs 0.5%(0.1% to 3.2%) in HIV-negative MSM; p=0.01). Conclusions In this small feasibility study, MSM with rectal CT appeared to be at appreciable risk of GII. Asymptomatic carriage may play a role in sexual transmission of GII.