The CoLab score is associated with SARS-CoV-2 viral load during admission in individuals admitted to the intensive care unit: the CoLaIC cohort study.

OBJECTIVES: The present study examines the temporal association between the changes in SARS-CoV-2 viral load during infection and whether the CoLab-score can facilitate de-isolation. METHODS: Nasal swabs and blood samples were collected from ICU-admitted SARS-CoV-2 positive patients at Maastricht UMC+ from March 25, 2020 to October 1, 2021. The CoLab-score was calculated based on 10 blood parameters and age and can range from -43 to 6. Three mixed effects analyses compared patient categories based on initial PCR Ct values (low; Ct≤20, mid; 20>Ct≤30, high; Ct>30), serial PCR Ct values to CoLab-scores over time, and the association between within-patient delta Ct values and CoLab-scores. RESULTS: In 324 patients, the median Ct was 33, and the median CoLab-score was -1.78. Mid (n=110) and low (n=41) Ct-categories had higher CoLab-scores over time (+0.60 points, 95 % CI; 0.04-1.17, and +0.28 points, 95 % CI -0.49 to 1.04) compared to the high Ct (n=87) category. Over time, higher serial Ct values were associated with lower serial CoLab-scores, decreasing by -0.07 points (95 % CI; -0.11 to -0.02) per day. Increasing delta Ct values were associated with a decreasing delta CoLab-score of -0.12 (95 % CI; -0.23; -0.01). CONCLUSIONS: The study found an association between lower viral load on admission and reduced CoLab-score. Additionally, a decrease in viral load over time was associated with a decrease in CoLab-score. Therefore, the CoLab-score may make patient de-isolation an option based on the CoLab-score.

Refining Timely Diagnosis of Early Syphilis by Using Treponema pallidum PCR or IgM Immunoblotting Next to Conventional Serology for Syphilis.

Treponema pallidum subsp. pallidum is a fastidious spirochete and the etiologic agent of syphilis, a sexually transmitted infection (STI). Syphilis diagnoses and disease staging are based on clinical findings and serologic testing. Moreover, according to most international guidelines, PCR analysis of swab samples from genital ulcers is included in the screening algorithm where possible. It has been suggested that PCR might be omitted from the screening algorithm due to low added value. As an alternative to PCR, IgM serology might be used. In this study, we wanted to establish the added value of PCR and IgM serology for diagnosing primary syphilis. Added value was defined as finding more cases of syphilis, preventing overtreatment, or limiting the extent of partner notification to more recent partners. We found that both PCR and IgM immunoblotting could aid the timely diagnosis of early syphilis in ~24% to 27% of patients. PCR has the greatest sensitivity and can be applied to cases with an ulcer with suspected reinfection or primary infection. In the absence of lesions, the IgM immunoblot could be used. However, the IgM immunoblot has better performance in cases with suspected primary infection than in reinfections. The target population, testing algorithm, time pressures, and costs should determine whether either test provides sufficient value to be implemented in clinical practice.

Chlamydia trachomatis Coinfection Does Not Influence Mycoplasma genitalium Bacterial Load in Urogenital Samples.

BACKGROUND: Mycoplasma genitalium (MG) is associated with urethritis in men and weakly associated with pelvic inflammatory disease in women. Mycoplasma genitalium coinfections with Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) are commonly reported; however, little is known about their interaction. One study suggested that MG/NG coinfections might increase the bacterial load of NG, which has been shown to have a higher transmission potential. As even less is known about the impact of a simultaneous MG/CT infection, we assessed whether patients with urogenital MG/CT coinfections have a higher bacterial load than patients with a single infection. METHODS: There were 1673 urogenital samples from patients from a population-based chlamydia study, and our sexually transmitted infection clinic tested for both CT and MG. When positive, the load was quantified. Nonparametric tests compared the CT and MG load, and linear regression analyses tested the association of the CT and MG load within a patient. RESULTS: In 60 MG-positive patients, MG load ranged from 1.7 to 6.0 log10 copies/ml, similar to the CT load distribution. Only 6 patients were MG-positive and CT-negative, but the MG load distribution was similar to that of CT-positive patients (n.s.). The MG and CT load was unrelated in coinfected persons (n.s.). CONCLUSIONS: We found no correlation between the CT and MG load in urogenital samples, and the MG load distribution was similar in CT-positive and CT-negative patients. These results could have implications for the transmission risk of these infections.

Incident urogenital and anorectal Chlamydia trachomatis in women: the role of sexual exposure and autoinoculation: a multicentre observational study (FemCure).

BACKGROUND: Anorectal infections with Chlamydia trachomatis (CT) are common in women visiting STI outpatient clinics. We here evaluated the risk posed by sexual exposure and by alternate anatomical site infection for incident anorectal and urogenital CT. METHODS: Prospective multicentre cohort study, FemCure. Participants were treated for CT, and after 4, 6, 8, 10 and 12 weeks, they self-collected anorectal and urogenital samples (swabs) for CT-DNA testing. We calculated the proportion with incident CT, that is, CT incidence (at weeks 6-12) by 2-week time-periods. Compared with no exposure (A), we estimated the risk of incident CT for (B) sexual exposure, (C) alternate site anatomic site infection and (D) both, adjusted for confounders and expressed as adjusted ORs with 95% CIs. RESULTS: We analysed data of 385 participants contributing 1540 2-week periods. The anorectal CT incidence was 2.9% (39/1343) (95 CI 1.8 to 3.6); 1.3% (A), 1.3% (B), 27.8% (C) and 36.7% (D). The ORs were: 0.91 (95% CI 0.32 to 2.60) (B), 26.0 (95% CI 7.16 to 94.34) (C), 44.26 (95% CI 14.38 to 136.21) (D).The urogenital CT incidence was 3.3% (47/1428) (95% CI 2.4 to 4.4); 0.7% (A), 1.9% (B), 13.9% (C) and 25.4% (D). The ORs were: 2.73 (95% CI 0.87 to 8.61) (B), 21.77 (95% CI 6.70 to 70 71) (C) and 49.66 (95% CI 15.37 to 160.41) (D). CONCLUSIONS: After initial treatment, an alternate anatomical site CT infection increased the risk for an incident CT in women, especially when also sex was reported. This may suggest a key role for autoinoculation in the re-establishment or persistence of urogenital and anorectal chlamydia infections.

Determinants associated with viable genital or rectal Chlamydia trachomatis bacterial load (FemCure).

BACKGROUND: Chlamydia trachomatis (CT) is routinely diagnosed by nucleic acid amplification tests (NAATs), which are unable to distinguish between nucleic acids from viable and non-viable CT organisms. OBJECTIVES: We applied our recently developed sensitive PCR (viability PCR) technique to measure viable bacterial CT load and explore associated determinants in 524 women attending Dutch sexual health centres (STI clinics), and who had genital or rectal CT. METHODS: We included women participating in the FemCure study (Netherlands, 2016-2017). At the enrolment visit (pre-treatment), 524 were NAAT positive (n=411 had genital and rectal CT, n=88 had genital CT only and n=25 had rectal CT only). We assessed viable rectal and viable genital load using V-PCR. We presented mean load (range 0 (non-viable) to 6.5 log10 CT/mL) and explored potential associations with urogenital symptoms (coital lower abdominal pain, coital blood loss, intermenstrual bleeding, altered vaginal discharge, painful or frequent micturition), rectal symptoms (discharge, pain, blood loss), other anatomical site infection and sociodemographics using multivariable regression analyses. RESULTS: In genital (n=499) CT NAAT-positive women, the mean viable load was 3.5 log10 CT/mL (SD 1.6). Genital viable load was independently associated with urogenital symptoms-especially altered vaginal discharge (Beta=0.35, p=0.012) and with concurrent rectal CT (aBeta=1.79; p<0.001). Urogenital symptoms were reported by 50.3% of women; their mean genital viable load was 3.6 log10 CT/mL (vs 3.3 in women without symptoms). Of 436 rectal CT NAAT-positive women, the mean rectal viable load was 2.2 log10 CT/mL (SD 2.0); rectal symptoms were reported by 2.5% (n=11) and not associated with rectal viable load. CONCLUSION: Among women diagnosed with CT in an outpatient clinical setting, viable genital CT load was higher in those reporting urogenital symptoms, but the difference was small. Viable genital load was substantially higher when women also had a concurrent rectal CT. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02694497.

Controversies and evidence on Chlamydia testing and treatment in asymptomatic women and men who have sex with men: a narrative review.

BACKGROUND: Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection (STI) worldwide. CT is mainly asymptomatic. Test-and-treat strategies are widely implemented to prevent transmission and complications. Strategies are not without controversy in asymptomatic women and men who have sex with men (MSM). Concerns are emerging to test and treat asymptomatic persons for urogenital CT ('Controversy 1') and pharyngeal or rectal CT ('Controversy 2'), whereby testing symptomatic persons is not under debate. Opposed views in CT treatment involve using azithromycin versus doxycycline ('Controversy 3'). The objective of this review is to provide coverage of these public health and clinical controversies by reviewing the current scientific evidence. METHODS: A literature search was performed using PubMed for relevant publications between 2018 and September 2021, and iterative retrieval of additional relevant publications. RESULTS: Controversy 1. In women, the majority of asymptomatic CT are at the urogenital site, and detections mostly include viable CT. CT easily transmits to a partner and potentially also between the vaginal and rectal areas; the clinical impact of urogenital CT is established, although risks for adverse outcomes are uncertain. Wide-scale testing in asymptomatic women has not resulted in reduced prevalence. In MSM, evidence for the clinical impact of asymptomatic urogenital CT is lacking. Controversy 2. Rectal CT is common in women diagnosed with urogenital CT, but the clinical impact of asymptomatic rectal CT is uncertain. In MSM, rectal CT is common, and most CT infections are at the rectal site, yet the risk of longer term complications is unknown. In both sexes, pharyngeal CT is uncommon and has no documented clinical impact. Controversy 3. In the treatment of rectal CT, doxycycline has superior effectiveness to azithromycin. Evidence has also accumulated on the harms of test-and-treat strategies. CONCLUSIONS: Current practices vary widely, from widescale test-and-treat approaches to more individual patient- and partner-level case management. Choosing which asymptomatic people to test at what anatomic site, and whether to test or not, requires an urgent (re-)definition of the goals of testing and treating asymptomatic persons. Treatment guidelines are shifting toward universal doxycycline use, and clinical practice now faces the challenge of implementation.

Effectiveness of Commonly Used Contact Lens Disinfectants Against SARS-CoV-2.

OBJECTIVE: To assess the effect of commonly used contact lens disinfectants against severe acute respiratory syndrome corona virus 2 (SARS-CoV-2). METHODS: The efficacy of five disinfectant solutions against SARS-CoV-2 was tested in the presence and absence of contact lenses (CLs). Three types of unused CLs (hard gas permeable, soft hydrogel, and soft silicone hydrogel) and worn silicone hydrogel CLs were tested. Contact lenses were infected with SARS-CoV-2 and disinfected at various times, with and without rubbing and rinsing, as per manufacturer's instructions. Reverse-transcriptase polymerase chain reaction (RT-PCR) and viability polymerase chain reaction (PCR) were applied to detect SARS-CoV-2 RNA and viral infectivity of SARS-CoV-2, respectively. RESULTS: In the presence of SARS-CoV-2-infected CLs, no SARS-CoV-2 RNA could be detected when disinfectant solutions were used according to the manufacturer's instructions. When SARS-Co-V2-infected CLs were disinfected without the rub-and-rinse step, SARS-CoV-2 RNA was detected at almost each time interval with each disinfecting solution tested for both new and worn CLs. In the absence of CLs, viable SARS-CoV-2 was detected with all disinfectant solutions except Menicon Progent at all time points. CONCLUSIONS: Disinfectant solutions effectively disinfect CLs from SARS-CoV-2 if manufacturer's instructions are followed. The rub-and-rinse regimen is mainly responsible for disinfection. The viability PCR may be useful to indicate potential infectiousness.

Men and Women Have an Equal Oropharyngeal and Anorectal Chlamydia trachomatis Bacterial Load: A Comparison of 3 Anatomic Sites.

BACKGROUND: The Chlamydia trachomatis bacterial load could have impact on transmission and sequelae. This is the first study providing comparison of C. trachomatis load at 3 anatomic sites estimated by cycle quantification (Cq) values. METHODS: Data from 7900 C. trachomatis-positive samples were included (2012-2018). Cq value was used as an inversely proportional measure for C. trachomatis load. Multivariable linear regression analyses assessed differences in mean Cq values. RESULTS: Vaginal swabs had the lowest Cq values (31.0) followed by urine (32.5), anorectal swabs (34.0), and oropharyngeal swabs (36.8) (P < .001). Men and women had similar oropharyngeal (36.4 vs 37.3; P = .13) and anorectal (34.2 vs 33.9; P = .19) Cq values. Men (32.2) and women (30.7) aged <25 years had lower urogenital Cq values than men (32.8) and women (31.9) aged ≥25 years (P < .001). HIV-positive patients had higher urogenital Cq values than HIV-negative patients (33.8 vs 32.6; P < .03). CONCLUSIONS: Men and women have a similar C. trachomatis load at extragenital locations arguing for similar transmission potential and clinical relevance. Older patients and HIV-coinfected patients had lower C. trachomatis load, suggesting exposure to previous C. trachomatis infections potentially leading to partial immunity reducing load.

Oropharyngeal Chlamydia trachomatis in women; spontaneous clearance and cure after treatment (FemCure).

OBJECTIVES: Women attending STI clinics are not routinely tested for oropharyngeal Chlamydia trachomatis (CT) infections. We aimed to assess spontaneous clearance of oropharyngeal CT and cure after antibiotic treatment in women. METHODS: Women with vaginal or rectal CT (n=560) were recruited at STI clinics in 2016-2017, as part of the FemCure study (prospective cohort study). We included participants' data from week -1, that is, the diagnosis at initial visit, when clinics applied selective oropharyngeal testing. At week -1, a total of 241 women were oropharyngeally tested (30 positive) and 319 were untested. All FemCure participants provided nurse-collected oropharyngeal samples at study enrolment, that is, week 0, just prior to treatment (n=560), and after treatment at weeks 4 (n=449), 8 (n=433) and 12 (n=427). Samples were tested by nucleic acid amplification test, and at week 0 also by viability testing by viability PCR. Proportions of oropharyngeal CT test results were presented to represent spontaneous clearance and cure. RESULTS: Of 30 women diagnosed with oropharyngeal CT at week -1, fifteen (50%) were negative at week 0 after a median of 9 days, that is, 'spontaneous clearance'. At week 0, a total of 560 participants were tested, and 46 (8.8%) were oropharyngeal CT positive; 12 of them (26.1%) had viable CT. Of the 46 positive, 36 women had an oropharyngeal test after treatment; 97.2% (35/36) were negative at week 4, that is, 'cure'. Of all women with follow-up visits, the proportion of oropharyngeal CT positive was between 0.5% and 1.6% between weeks 4 and 12. Of those not tested at week -1 (n=319), 8.5% (n=27) were oropharyngeal positive at week 0. CONCLUSIONS: The clinical importance of oropharyngeal CT in women is debated. We demonstrated that spontaneous clearance of oropharyngeal CT among women is common; of those who did not clear for CT, three-quarters had non-viable CT. After regular treatment with azithromycin or doxycycline, cure rate (97%) of oropharyngeal CT is excellent. TRIAL REGISTRATION NUMBER: NCT02694497.

Culture-Independent Genotyping Revealed 3 Strain Clusters in a Potential Neisseria gonorrhoeae Outbreak in Young Heterosexuals (<25 Years), the Netherlands, October 2017 to March 2019.

BACKGROUND: Investigation was undertaken to determine the genetic relatedness of Neisseria gonorrhoeae (NG) isolates of young (<25 years) heterosexuals of a potential outbreak from October 2017 to March 2019 in South-Limburg, the Netherlands. METHODS: Data and residual sample material of routine diagnostics were retrieved for outbreak cases (78/81), young heterosexuals at baseline (January 2016 to September 2017, n = 30), and men who have sex with men (2018, n = 47). Total DNA was isolated, and NG was genotyped using culture-free NG multiantigen sequence typing. Sanger sequence data were used to construct a phylogenetic tree. Cases of outbreak clusters were geographically mapped, and descriptive analyses were performed on patient characteristics, comparing these clusters. RESULTS: Outbreak investigation showed 81 cases of young heterosexuals between October 2017 and March 2019 (4.5 per month) compared with 30 between January 2016 and September 2017 (1.4 per month), which was considered as baseline. Culture-independent genotyping of NG was performed to assess the genetic relatedness, as only 21 outbreak cases were culture confirmed. This revealed 3 independent outbreak clusters G2 (n = 18), G13113 (n = 11), and GNewST (n = 24). None of the clusters were geographically linked or introduced by bridging with men who have sex with men networks. Number of sex partners reported by men and Chlamydia trachomatis coinfection were associated with clusters G2 and GNewST, respectively. CONCLUSIONS: Culture-independent typing proved to be essential to identify the 3 outbreak clusters. However, targeted interventions were difficult because information on sex partners was limited. Therefore, prospective culture-independent typing could be used for early outbreak detection and aid in transmission prevention.

Combining stool and stories: exploring antimicrobial resistance among a longitudinal cohort of international health students.

BACKGROUND: Antimicrobial resistance (AMR) is a global public health concern that requires transdisciplinary and bio-social approaches. Despite the continuous calls for a transdisciplinary understanding of this problem, there is still a lack of such studies. While microbiology generates knowledge about the biomedical nature of bacteria, social science explores various social practices related to the acquisition and spread of these bacteria. However, the two fields remain disconnected in both methodological and conceptual levels. Focusing on the acquisition of multidrug resistance genes, encoding extended-spectrum betalactamases (CTX-M) and carbapenemases (NDM-1) among a travelling population of health students, this article proposes a methodology of 'stool and stories' that combines methods of microbiology and sociology, thus proposing a way forward to a collaborative understanding of AMR. METHODS: A longitudinal study with 64 health students travelling to India was conducted in 2017. The study included multiple-choice questionnaires (n = 64); a collection of faecal swabs before travel (T0, n = 45), in the first week in India (T1, n = 44), the second week in India (T2, n = 41); and semi-structured interviews (n = 11). Stool samples were analysed by a targeted metagenomic approach. Data from semi-structured interviews were analysed using the method of thematic analysis. RESULTS: The incidence of ESBL- and carbapenemase resistance genes significantly increased during travel indicating it as a potential risk; for CTX-M from 11% before travel to 78% during travel and for NDM-1 from 2% before travel to 11% during travel. The data from semi-structured interviews showed that participants considered AMR mainly in relation to individual antibiotic use or its presence in a clinical environment but not to travelling. CONCLUSION: The microbiological analysis confirmed previous research showing that international human mobility is a risk factor for AMR acquisition. However, sociological methods demonstrated that travellers understand AMR primarily as a clinical problem and do not connect it to travelling. These findings indicate an important gap in understanding AMR as a bio-social problem raising a question about the potential effectiveness of biologically driven AMR stewardship programs among travellers. Further development of the 'stool and stories' approach is important for a transdisciplinary basis of AMR stewardship.

COVID-19: first long-term care facility outbreak in the Netherlands following cross-border introduction from Germany, March 2020.

BACKGROUND: The Dutch province of Limburg borders the German district of Heinsberg, which had a large cluster of COVID-19 cases linked to local carnival activities before any cases were reported in the Netherlands. However, Heinsberg was not included as an area reporting local or community transmission per the national case definition at the time. In early March, two residents from a long-term care facility (LTCF) in Sittard, a Dutch town located in close vicinity to the district of Heinsberg, tested positive for COVID-19. In this study we aimed to determine whether cross-border introduction of the virus took place by analysing the LTCF outbreak in Sittard, both epidemiologically and microbiologically. METHODS: Surveys and semi-structured oral interviews were conducted with all present LTCF residents by health care workers during regular points of care for information on new or unusual signs and symptoms of disease. Both throat and nasopharyngeal swabs were taken from residents suspect of COVID-19, based on regional criteria, for the detection of SARS-CoV-2 by Real-time Polymerase Chain Reaction. Additionally, whole genome sequencing was performed using a SARS-CoV-2 specific amplicon-based Nanopore sequencing approach. Moreover, twelve random residents were sampled for possible asymptomatic infections. RESULTS: Out of 99 residents, 46 got tested for COVID-19. Out of the 46 tested residents, nineteen (41%) tested positive for COVID-19, including 3 asymptomatic residents. CT-values for asymptomatic residents seemed higher compared to symptomatic residents. Eleven samples were sequenced, along with three random samples from COVID-19 patients hospitalized in the regional hospital at the time of the LTCF outbreak. All samples were linked to COVID-19 cases from the cross-border region of Heinsberg, Germany. CONCLUSIONS: Sequencing combined with epidemiological data was able to virtually prove cross-border transmission at the start of the Dutch COVID-19 epidemic. Our results highlight the need for cross-border collaboration and adjustment of national policy to emerging region-specific needs along borders in order to establish coordinated implementation of infection control measures to limit the spread of COVID-19.

Obligatory medical prescription of antibiotics in Russia: Navigating formal and informal health-care infrastructures.

Antimicrobial resistance control programmes often aim to "fix" the behaviour of antibiotic users and prescribers. Such behavioural interventions have been widely criticised in social science literature for being inefficient and too narrow in scope. Drawing on these criticisms, this article analyses how political programmes for fixing antibiotic behaviours were adapted into the practices of health-care professionals and patients in Russia. In 2018, we conducted interviews with medical doctors, pharmacists and patients in a Russian city; focusing on their practices around the policy requirement introduced in 2017 which obligated medical prescriptions of antibiotics. We conceptualised the obligatory medical prescription as a political technique which sought to change practices of self-treatment and over-the-counter sales of medications by establishing doctors as an obligatory passage point to access antibiotics. Our analysis shows that the requirement for medical prescriptions does not fulfil the infrastructural gaps that influence antibiotic practices. By navigating the antibiotic prescriptions, doctors, pharmacists and patients informally compensate for the gaps in the existing infrastructure creating informal networks of antibiotic care parallel to the requirement of obligatory prescriptions. Following these informal practices, we could map the inconsistencies in the current policy approaches to tackle AMR as a behavioural rather than infrastructural problem.

Men and Women Have Similar Neisseria gonorrhoeae Bacterial Loads: a Comparison of Three Anatomical Sites.

Neisseria gonorrhoeae is a common bacterial sexually transmitted infection (STI). Currently, there are limited data on the bacterial load in both men and women and on both genital and extragenital sites. Therefore, we quantified N. gonorrhoeae bacterial loads in a large population of women, heterosexual men, and men who have sex with men (MSM) at three different anatomical sites. N. gonorrhoeae-positive samples (n = 1265) of STI clinic consultations (n = 944) were tested for N. gonorrhoeae with the Roche Cobas 4800 system, and quantification cycle (Cq) values were used as an inversely proportional measure for N. gonorrhoeae bacterial load after interpolation from a standard curve. Bacterial loads were compared between sample materials and sexes using t tests. The following mean N. gonorrhoeae loads were observed: urine, 4.5 ± 1.0 log10 CFU/ml; vaginal swabs, 4.3 ± 1.1 log10 CFU/ml; anorectal swabs (women), 4.0 ± 1.2 log10 CFU/ml; anorectal swabs (men), 4.5 ± 1.3 log10 CFU/ml; oropharyngeal swabs (women), 2.8 ± 0.9 log10 CFU/ml; and oropharyngeal swabs (men), 3.2 ± 1.0 log10 CFU/ml. Oropharyngeal swabs had a significantly lower N. gonorrhoeae load (P < 0.001) than genital and anorectal samples. Loads did not differ between men and women. This is the first study that determined N. gonorrhoeae load in both women and men at three anatomical sites. The substantial N. gonorrhoeae load at all sample sites suggest that all sites may have transmission potential. However, the oropharyngeal site presents the lowest bacterial load. Men and women have a similar N. gonorrhoeae loads on separate anatomical sites, arguing for similar transmission potential and similar clinical relevance.

Assessment of rectal Chlamydia trachomatis viable load in women by viability-PCR.

OBJECTIVES: In recent years, studies have demonstrated frequent rectal Chlamydia trachomatis (CT) detection in women, irrespective of reported anal sex or rectal symptoms. However, the clinical relevance and public health implication of rectal CT detection in women remain under debate. Therefore, evaluating CT viability may provide more insight into the relevance of standard routine nucleic acid amplification test (NAAT)-positive results. METHODS: In this cross-sectional explorative study, a convenience sample of female patients at our STI clinic aged 18 years or older, diagnosed with vaginal and/or rectal CT, were invited to participate. On return for treatment, rectal CT-diagnosed women were instructed to self-collect rectal swab samples before being treated. Standard COBAS 4800 CT/NG routine NAAT testing was applied for CT diagnosis. Rectal viable CT load was evaluated by using viability-PCR (V-PCR). RESULTS: 53 women with rectal CT were included in this study; 86.8% (46/53) had a quantifiable rectal total CT load. Of women with quantifiable samples, 52.2% (24/46) had viable CT detected from rectal swabs by V-PCR, with a mean rectal viable CT load of 3.31 log10 CT/mL (range 1.16-6.22). No statistically significant difference (p=0.73) was observed in the mean rectal viable CT load of women with an indication for rectal testing (n=9) and without (n=15), 3.20 log10 CT/mL (range 2.06-4.36) and 3.38 log10 CT/mL (range 1.16-6.22), respectively. CT culture yielded positive test results from rectal swabs in 22.6% (12/53) of rectal CT NAAT-diagnosed women. Of women with viable rectal CT by V-PCR (n=24), 50% (12/24) were positive by CT culture. CONCLUSIONS: Overall, the detection of high rectal viable CT loads in this study indicates that rectal CT in some women might represent a currently ongoing infection rather than just the presence of remnant DNA from dead bacteria or only contamination from an active vaginal CT infection.

Spontaneous clearance of Chlamydia trachomatis accounting for bacterial viability in vaginally or rectally infected women (FemCure).

OBJECTIVES: Spontaneous clearance of Chlamydia trachomatis (CT) infections can occur between diagnosis and treatment. We followed CT patients to assess clearance using a conventional definition (no total CT-DNA, assessed by routine quantitative PCR methods) and a definition accounting for viability, assessed by viability PCR testing. METHODS: Three outpatient STI clinics included CT-diagnosed women (The Netherlands, 2016-2017, FemCure study); participants had vaginal CT (vCT) and rectal CT (rCT) (group A: n=155), vCT and were rectally untested (group B: n=351), single vCT (group C: n=25) or single rCT (group D: n=29). Follow-up (median interval 9 days) vaginal and rectal samples underwent quantitative PCR testing (detecting total CT-DNA). When PCR positive, samples underwent V-PCR testing to detect 'viable CT' (CT-DNA from intact CT organisms; V-PCR positive). 'Clearance' was the proportion PCR-negative patients and 'clearance of viable CT' was the proportion of patients testing PCR negative or PCR positive but V-PCR negative. We used multivariable logistic regression analyses to assess diagnosis group (A-D), age, days since initial CT test (diagnosis) and study site (STI clinic) in relation to clearance and clearance of viable CT. RESULTS: Clearance and clearance of viable CT at both anatomic sites were for (A) 0.6% and 3.9%; (B) 5.4% and 9.4%; (C) 32.0% and 52.0% and (D) 27.6% and 41.4%, respectively. In multivariate analyses, women with single infections (groups C and D) had higher likelihood of clearance than women concurrently infected with vCT and rCT (p<0.001).Of rectally untested women (group B), 76.9% had total CT-DNA and 46.7% had viable CT (V-PCR positive) at the rectal site. CONCLUSIONS: Of untreated female vCT patients who had CT also at the rectal site, or who were rectally untested, only a small proportion cleared CT (in fact many had viable CT) at their follow-up visit (median 9 days). Among single site infected women clearance was much higher. TRIAL REGISTRATION NUMBER: NCT02694497.

Men and Women Repeatedly Infected With Chlamydia trachomatis Have a Lower Urogenital Bacterial Load.

We assessed whether patients repeatedly infected with Chlamydia trachomatis (CT) have a lower urogenital or anorectal CT load. A CT-positive retest was independently associated with higher vaginal and higher urine Cq values (P<0.01). Partial immunity could play a role in repeat urogenital infections, potentially not in anorectal infections.

The characteristics of patients frequently tested and repeatedly infected with Chlamydia trachomatis in Southwest Limburg, the Netherlands.

BACKGROUND: Repeat Chlamydia trachomatis (CT) infections are common. To better understand the characteristics of patients frequently infected with CT at our sexually transmitted infection (STI) care services, we assessed the differences between patients repeatedly infected with CT and those who repeatedly tested negative. METHODS: In this cross-sectional analysis of cohort data, we assessed individuals tested for CT at different STI care providers between 2011 and mid-2018 in Southwest Limburg, the Netherlands (n = 17,616). Patients with ≥2 repeat CT infections in the study period were categorized as "patients with repeat CT infections." Multivariable logistic regression analyses were performed for the binary outcome measure: patients with repeat CT infections versus patients who repeatedly tested negative (reference group). Additional analyses were performed for only the STI clinic population. RESULTS: Patients aged < 25 years (OR: 1.83; 95%CI:1.38-2.43), co-infected with HIV (OR: 2.07; 95%CI: 1.02-4.22) or co-infected with Neisseria gonorrhoeae (NG) (OR: 5.04; 95%CI: 3.33-7.63) had more repeat CT infections. In additional analyses among exclusively STI clinic visitors, patients with urogenital symptoms (OR: 2.17; 95%CI: 1.41-3.35), and patients notified for STIs (OR: 4.55; 95%CI: 3.17-6.54) had more frequent repeat CT infections. CONCLUSIONS: Patients aged < 25 years and patients coinfected with HIV or NG had more frequent repeat CT infections, accounting for ~ 20% of the diagnosed CT infections. These patients are likely at the highest risk for transmitting and acquiring CT. Therefore, testing and retesting this group remains important to enhance CT control.

Chlamydia trachomatis and the Risk of Pelvic Inflammatory Disease, Ectopic Pregnancy, and Female Infertility: A Retrospective Cohort Study Among Primary Care Patients.

BACKGROUND: We evaluated the risk of pelvic inflammatory disease (PID), ectopic pregnancy, and infertility in women with a previous Chlamydia trachomatis (CT) diagnosis compared with women who tested negative for CT and CT untested women, considering both targeted and incidental (ie, prescribed for another indication) use of CT-effective antibiotics. METHODS: This was a retrospective study of women aged 12-25 years at start of follow-up within the Clinical Practice Research Datalink GOLD database linked to index of multiple deprivation quintiles, 2000-2013. CT test status and antibiotic use were determined in a time-dependent manner. Risk of PID, ectopic pregnancy, or female infertility were evaluated using of Cox proportional hazard models. RESULTS: We studied 857 324 women, contributing 6 457 060 person-years. Compared with women who tested CT-negative, women who tested CT-positive had an increased risk of PID (adjusted hazard ratio [aHR], 2.36; 95% confidence interval [CI], 2.01-2.79), ectopic pregnancy (aHR, 1.87; 95% CI, 1.38-2.54), and infertility (aHR, 1.85; 95% CI, 1.27-2.68). The PID risk was higher for women with 2 or more positive CT tests than those with 1 positive test. PID risk increased with the number of previous antibiotic prescriptions, regardless of CT test status. CONCLUSIONS: We showed an association between CT-positive tests and 3 adverse reproductive health outcomes. Moreover, this risk increased with repeat CT infections. CT-effective antibiotic use showed no decreased risks of subsequent PID regardless of CT history. Our results confirm the reproductive health burden of CT, which requires adequate public health interventions.

Treatment Effectiveness of Azithromycin and Doxycycline in Uncomplicated Rectal and Vaginal Chlamydia trachomatis Infections in Women: A Multicenter Observational Study (FemCure).

BACKGROUND: Rectal infections with Chlamydia trachomatis (CT) are prevalent in women visiting a sexually transmitted infection outpatient clinic, but it remains unclear what the most effective treatment is. We assessed the effectiveness of doxycycline and azithromycin for the treatment of rectal and vaginal chlamydia in women. METHODS: This study is part of a prospective multicenter cohort study (FemCure). Treatment consisted of doxycycline (100 mg twice daily for 7 days) in rectal CT-positive women, and of azithromycin (1 g single dose) in vaginally positive women who were rectally untested or rectally negative. Participants self-collected rectal and vaginal samples at enrollment (treatment time-point) and during 4 weeks of follow-up. The endpoint was microbiological cure by a negative nucleic acid amplification test at 4 weeks. Differences between cure proportions and 95% confidence intervals (CIs) were calculated. RESULTS: We analyzed 416 patients, of whom 319 had both rectal and vaginal chlamydia at enrollment, 22 had rectal chlamydia only, and 75 had vaginal chlamydia only. In 341 rectal infections, microbiological cure in azithromycin-treated women was 78.5% (95% CI, 72.6%-83.7%; n = 164/209) and 95.5% (95% CI, 91.0%-98.2%; n = 126/132) in doxycycline-treated women (difference, 17.0% [95% CI, 9.6%-24.7%]; P < .001). In 394 vaginal infections, cure was 93.5% (95% CI, 90.1%-96.1%; n = 246/263) in azithromycin-treated women and 95.4% (95% CI, 90.9%-98.2%; n = 125/131) in doxycycline-treated women (difference, 1.9% [95% CI, -3.6% to 6.7%]; P = .504). CONCLUSIONS: The effectiveness of doxycycline is high and exceeds that of azithromycin for the treatment of rectal CT infections in women. CLINICAL TRIALS REGISTRATION: NCT02694497.