Background and Objectives: Currently, no information is available about the number of Chlamydia trachomatis (CT) tests performed, testing facilities available or diagnostic methods used in Germany. This study aimed to map CT diagnostic facilities so that representative laboratories can be recruited for CT sentinel surveillance.Methods: Using a questionnaire, we collected information about population coverage, the number of tests performed, accreditation and current testing methods and systems for German facilities that potentially off er CT diagnostics.Results: Overall, 725/1 504 (48 %) facilities responded; of the respondents, 143 reported that they perform CT diagnostics. Of the laboratories performing diagnostics, 45 % were privately owned, and 42 % were located in a hospital. Of the laboratories that provided information about their catchment area, 61 % received samples from at least one federal state and therefore covered more than their surrounding area. The median length of time that CT diagnostics had been performed was 11.5 years. Over half (54 %) of the laboratories that provided information on their accreditation status were accredited, for a median duration of 6 years. In accordance with national guidelines, 77 % used nucleic acid amplification tests (NAAT) for acute CT infections.Conclusions: The long duration since Ct diagnostics have been performed and laboratories have been accredited can be seen as an indication of the high diagnostic quality of German laboratories. Additionally, laboratories mostly serviced doctors and patients from a large region and are not representative for people living in the area where the lab is located. This has to be considered when sampling representative labs for CT sentinel surveillance and further epidemiological studies.

Aim To estimate the prevalence of HIV-TDR and ADR in one resistance study of the German ClinSurv-HIV cohort. Method The ClinSurv study is a national open multi-centre long term observational cohort with 15 participating clinical centres (n = 16,750 patients; 31.12.2011). In a resistance study all ClinSurv patients in five centres were identified. Sequences were processed through the Stanford University Genotypic Resistance Interpretation Algorithm ( www. hivdb.stanford.edu; HIVdb version 6.1.1F; 2012 webService version beta-1.0.1) to identify mutations and to determine drug susceptibility. Sequences were analysed by using different lists of mutations (Bennett D. 2009; Johnson V. 2011). Trends in the prevalence of drug resistance mutations were calculated by logistic regression. Results A total of 9,528 patients from five study centres were included into analysis. 4,989 viral sequences were collected from 34% (3,267/9,528) of these patients. 47% (2,365/4,989) of sequences were produced from patients being treatment naïve and 50% (2,495/4,989) from patients under treatment. TDR was identified in 10% (203/1,950) of viral strains. The prevalence of TDR over time was stable at 10.4% (95% CI 9.1–11.8; OR: 0.98; 95% CI 0.92–1.04; p for trend = 0.6; 2001–2011). NRTI-resistance was determined in 7% (128/1,950), followed by 3% NNRTI- and PI-resistance, respectively (NNRTI: 61/1,950; PI: 56/1,950). Prevalence of ADR in treated patients was high (61%; 1,500/2,453 of sequences) but declined significantly over time (OR: 0.8; 95% CI 0.77–0.83; p for trend < 0.001; 2001–2011). Within drug classes NNRTI-resistance was predominant (56%; 834/1503), followed by NRTI-resistance in 52% (1,139/2,194) of sequences of patients with ADR exposed to these drug classes. PI-resistance was identified in 30% (543/1778). Integrase-resistance was determined in 8% (13/161) of integrase-sequences. Discussion Prevalence of TDR is highly stable in this unselected study population, whereas ADR declined significantly over the time, indicating that this decline was presumably influenced by ART related effects, broader resistance testing and resistance test guided therapy.