[Rapid diagnosis of sexually transmitted infections : Joint statement of DSTIG, RKI, and PEI, as well as the reference centers for HIV, HBV, and HCV and consulting laboratories for Chlamydia, gonococci, and Treponema pallidum]. / Schnelltestdiagnostik sexuell übertragbarer Infektionen : Gemeinsame Stellungnahme von DSTIG, RKI, PEI sowie den Referenzzentren für HIV, HBV und HCV und Konsiliarlaboren für Chlamydien, Gonokokken und Treponema pallidum.

In February 2019, the fourth expert meeting on rapid diagnostic tests (RDTs) for sexually transmitted infections (STI) was held at the Robert Koch Institute (RKI) in Berlin. Novel technical developments and new aspects of RDT applications were discussed by representatives from the German STI Society (DSTIG); RKI; the Paul Ehrlich Institute; national reference centers for HIV, HBV, and HCV; and reference laboratories for Chlamydia, gonococci, and Treponema pallidum.As a result of this meeting, we present a revision of the joint statement on STI diagnostics with RDTs from 2017. The Regulation (EU) 2017/746 of the European Parliament and of the Council on in vitro diagnostic medical devices became effective in May 2017 and includes more stringent regulatory requirements for RDTs, mainly concerning conformity of manufacturing processes and performance characteristics of class D in vitro diagnostics (detection of HIV, HBV, HCV, and T. pallidum). Some RDTs for HIV, HCV, and T. pallidum have been evaluated in clinical studies and/or were WHO prequalified and may be used in low-threshold services. Among them are some HIV RDTs available and approved for self-testing. In addition, some HBV RDTs based on detection of HBs antigen (HBsAg) received WHO prequalification. However, false negative results may occur in samples with low HBsAg levels, as for instance in HIV-coinfected patients receiving antiretroviral therapy. For Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), antigen-based RDTs still do not allow reliable detection of infection. Only PCR-based CT/NG RDTs possess sufficient diagnostic accuracy to be used as point-of-care tests. Rapid PCR tests for NG, however, do not provide any information about antimicrobial resistance.

Schnelltest-Diagnostik sexuell übertragbarer Infektionen in niedrigschwelligen Einrichtungen : Gemeinsame Stellungnahme des RKI, PEI und der DSTIG.

On February 5th, 2016 an expert meeting on rapid diagnostic tests (RDT) for sexually transmitted infections (STI) was held in Berlin at the Robert-Koch-Institute. The aim of the conference was to update a former evaluation of RDTs for diagnosis of HIV, HBV, HCV, T. pallidum, C. trachomatis and N. gonorrhoeae in low-threshold counseling services for STI that had been published after the previous meeting in 2012. According to the strategy to control HIV, hepatitis B and C and other STI, recently adopted by the German Government, there is a lack of test capabilities and a demand for more testing services as well as improved access to testing. Using RDTs as low-threshold test services in counseling centers or even for testing at home may provide an important option to lower the barrier of testing. Based on performance data evaluated in clinical trials some RDTs for HIV, HCV and syphilis are quite well suited as a point-of-care Test (POCT). In contrast, sufficient diagnostic accuracy for detection of C. trachomatis and N. gonorrhoeae can only be achieved by PCR-based POCTs. In Germany the use of POCTs is subjected to legal stipulations of IfSG and MPG. Of importance, it is not allowed to deliver HIV tests to private persons for home testing (§ 11, MPG). Furthermore, both assessment and communication of infectious diseases are reserved to the physician and must not happen as remote diagnostics (§ 24, IfSG). In addition, like all laboratory tests, RDTs are subject to quality assessment according to guidelines of the German Medical Association.

Evaluation of two rapid screening assays for detecting hepatitis C antibodies in resource-constrained settings.

OBJECTIVE: To evaluate the diagnostic accuracy of the OraQuick HCV rapid antibody test from OraSure and the Multisure HCV antibody assay from MP Biomedicals. METHODS: Five seropanels from patients, intravenous drug users and blood donors with and without HCV infection were used on the two rapid immunochromatographic tests. Sensitivity, specificity and predictive values were calculated. In addition, seropanels from 10 seroconverters were used to assess early identification of HCV infection. The study was undertaken in a laboratory at Paul Ehrlich Institute in Germany. RESULTS: Panel 1 contained of 55 positive and 25 negative samples. The OraQuick HCV test had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 100% (95% CI: 86.3-100). The Multisure HCV test had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 96% (95% CI: 79.6-99.9). Panel 2 consisted of 193 pre-characterised anti-HCV-positive patient samples. The OraQuick HCV test identified 191 samples correctly and the Multisure HCV 192. The sensitivity was 99.0% (95% CI: 96.3-99.9) for the OraQuick HCV test and 99.5% (95% CI: 97.1-100) for the Multisure HCV test. Panel 3 was composed of seroconversion samples of 10 patients. The OraQuick HCV test detected all of these 10 infections while the Multisure HCV test detected six and was indeterminate on 2. Panel 4 included 53 anti-HCV negative blood samples from blood donors. Both tests correctly identified all 53. Panel 5 consisted of 26 samples of HCV/HIV co-infected patients. The sensitivity of the OraQuick HCV test was 65.2% (95% CI: 42.8-82.8) after 20 min and 73.9% (95% CI: 51.3-88.9) after 40 min of incubation. The Multisure HCV test had a sensitivity of 96.2% (95% CI: 80.4-99.9). CONCLUSION: This evaluation revealed good sensitivity for both rapid screening assays. The detection of seroconverters, however, was lower in the MutiSure HCV test. Therefore the MultiSure test should be used with hesitation in high incidence settings. The OraQuick gave HCV false-negative results in almost 25% of the HIV-positive sera. Therefore may the OraQuick be less suited in HIV prevalent areas.

International collaborative study on the 3rd WHO International Standard for hepatitis B surface antigen.

BACKGROUND: The WHO International Standard (IS) for hepatitis B surface antigen (HBsAg) is used to standardize HBsAg assays. Stocks of the 2nd IS for HBsAg are depleted. The proposal to establish its replacement was endorsed by WHO in 2012. OBJECTIVE: Preparation of a freeze-dried candidate 3rd IS (NIBSC 12/226); evaluation of its suitability in a WHO international collaborative study; calibration of its potency in International Units (IU). STUDY DESIGN: The 3rd IS is based on plasma-derived, purified, inactivated HBsAg from Vietnam. Qualitative and quantitative HBsAg assays were used to evaluate 12/226 alongside the 2nd IS and 1st IS. Blinded study samples included a duplicate of 12/226, a negative control and two diluted plasma samples representing hepatitis B virus (HBV) genotypes A and B. RESULTS: Twelve laboratories from 9 countries returned 22 data sets from 15 methods. The overall geometric mean potency of 12/226 is 47.3IU/mL (±13% CV) when compared to the 2nd IS with HBV subgenotype A2. The 3rd IS has HBV subgenotype B4 with a heterogeneous HBsAg subtype population of ayw1 and adw2. Some genotype-dependent effects on the inter-laboratory variability were observed but overall mean potencies were virtually identical irrespective of the IS used for calibration. Stability studies indicate that the candidate is stable for long-term use. CONCLUSIONS: 12/226 was established in October 2014 by the WHO Expert Committee on Biological Standardization as the 3rd IS for HBsAg with a potency of 47.3IU per ampoule maintaining the continuity in the standardization of HBsAg assays.

Diagnostic accuracy evaluation of the ImmunoFlow HCV rapid immunochromatographic test for the detection of hepatitis C antibodies.

2% of the world's population lives with a hepatitis C virus (HCV) infection with highest rates in developing countries. The most common mode of transmission takes place via unsafe blood transfusions and unsafe therapeutic injections. Thus, screening potential blood donors for hepatitis C infection is a must to ensure safe blood transfusions. Rapid immunochromatographic tests are the best suitable test format to be used for screening for blood donors in resource-limited settings. The ImmunoFlow HCV from Core Diagnostics was evaluated at the Paul-Ehrlich-Institute, Germany for its test accuracy on three seropanels. Panel 1 consisted of 26 HCV positive and 55 negative samples, panel 2 of 193 HCV positive samples. Panel 3 contained 116 samples of 10 patients during seroconversion period. 39 of these 116 samples were characterized as HCV positive. The HCV ImmunoFlow had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 100% (95% CI: 86.8-100) when samples of panel 1 were tested. 191 samples of the 193 samples in panel 2 were correctly by the HCV Immunoflow, resulting in a sensitivity of 99.0%. 9 of 10 HCV infections were detected by the HCV ImmunoFlow when panel 3 was used. This evaluation revealed good sensitivity of the HCV ImmunoFlow test from and compares favorably with the results from the WHO evaluation and a systematic review conducted of field evaluations of Hepatitis C rapid diagnostic and other point of care tests.

Evaluation of 17 CE-marked HBsAg assays with respect to clinical sensitivity, analytical sensitivity, and hepatitis B virus mutant detection.

Seventeen HBsAg assays, in use in the European market (CE-marked), were assessed for their diagnostic sensitivity using 38 commercially available seroconversion panels, and for their analytical sensitivity with the HBsAg ad and ay standards of the Paul-Ehrlich-Institut (PEI). In addition, the ability to detect HBsAg mutants was investigated by means of 21 recombinant HBsAg mutant samples and 5 natural mutants. Analysis of seroconversion data revealed that there were marked differences in the sensitivity among the CE-marked HBsAg assays. Differences in the window period between the most and the least sensitive assays were up to 2 weeks. Analytical sensitivities of the investigated assays ranged from 0.009 to 0.05 PEI-U/ml for HBsAg ad standard (relating to approximately 0.018 to 0.100 IU/ml of the 2nd WHO HBsAg standard) and 0.012 to 0.11 PEI-U/ml for the ay standard. Clinical and analytical sensitivities were basically correlated. The capacity to detect mutant HBsAg forms was influenced by the assay format and the properties of the monoclonal antibodies used for coating of the solid phase or in the conjugate. While some assays detected all mutants others exhibited weaknesses especially in recognising HBsAg mutations affecting loop 2 of the HBsAg a-determinant. The results obtained with the recombinant mutants were largely confirmed by the investigation of clinical samples. The study gives a broad overview of the current state of the art of about 70% of the HBsAg assays currently available in Europe. The overall sensitivity has not been improved further since 1995 when the most sensitive assay was introduced into the market. In addition, detection of HBsAg mutants seems problematic with several assays. It is concluded that there is potential to improve clinical sensitivity and mutant recognition of HBsAg assays.

Evaluation of the performance of 44 assays used in countries with limited resources for the detection of antibodies to hepatitis C virus.

BACKGROUND: This study was conducted by the International Consortium for Blood Safety (ICBS) and its Collaborating Center, the Paul Ehrlich Institute, to identify high-quality, affordable assays for the detection of hepatitis C virus (HCV) antibodies and make available information on their performance for the benefit of developing countries. STUDY DESIGN AND METHODS: Forty-four assays were evaluated for their sensitivity and specificity. The assays' sensitivity was evaluated on a characterized panel of 200 anti-HCV-positive samples comprising major HCV genotypes 1 through 6. Three seroconversion panels were used to estimate sensitivity in the early infectious phase. Specificity was evaluated with a characterized ICBS-negative panel of 181 verified negative samples. RESULTS: Sensitivity was 100 percent for 15 assays, 99.5 percent for 11 assays, 99.0 percent for 6 assays, and less than 99.0 percent for 12 assays. The false-negative results found were not linked to the genotype. Anti-HCV detection in the early infectious phase was, on average, 16.7 days later than for tests licensed in the European Union. Specificity in 25 tests was 100 percent, whereas 11 assays showed 1 false-positive result (99.45%) and the other assays were nonspecific in 2 or more samples. Two assays were not supplied in sufficient quantity to test for specificity. CONCLUSIONS: On applying criteria for highest sensitivity (100%) and high specificity (> or =99.5%), 11 tests met the criteria. An additional 19 tests reached a performance comparable to WHO's criteria for human immunodeficiency virus antibody assays. The genotype diversity of HCV was found not to influence sensitivity of the assays.

Hepatitis B virus genotype G monoinfection and its transmission by blood components.

An acute hepatitis B virus (HBV) infection was diagnosed in a regular apheresis (plasma/platelet) donor by the hepatitis B surface antigen (HBsAg) assay and minipool nucleic acid amplification technology (NAT). The acute infection was confirmed by detection of anti-HBc (IgM) and anti-HBs 2 weeks later. The donor showed no clinical symptoms and had normal alanine aminotransferase levels. He had a history of weekly apheresis plasma or platelet donations. Archived material from the donor and the respective recipients was investigated by sensitive HBV NATs as part of a look-back procedure. HBV DNA was detectable in previous donations as well as in two recipients transfused with platelet concentrates. The rare HBV genotype G was identified in all HBV-DNA-positive samples. Strong evidence of genotype G monoinfection was obtained by clonal sequencing, HBV genotype line probe assay, genotype-specific NATs, and restriction pattern analysis. In contrast to previously described genotype G infections, which all appeared as coinfections with genotype A, neither the hepatitis B e antigen (HBeAg) nor anti-HBe was detectable in any of the samples. This shows that HBeAg is dispensable for viral replication. The delay in detecting HBsAg in both the donor and recipient samples may be explained by either decreased genotype G-specific synthesis of incomplete viral forms in early HBV infection or the lower sensitivity to genotype G of the current HBsAg assays. In conclusion, this reported case of an HBV infection was caused exclusively by genotype G.