Country-wide HIV incidence study complementing HIV surveillance in Germany

Serological methods exist that allow differentiating between recent and long-standing infections in persons infected with HIV. During a pilot study in Berlin between 2005 and 2007 methodologies have been evaluated. In a cross-sectional study blood samples, demographic, laboratory, clinical and behavioural data based on a KABP survey were collected from patients with newly diagnosed HIV infections. The BED-CEIA was used to determine recency of infection. Recent HIV infections contributed 54% (CI [95%]: 45; 64) in MSM and 16% (CI [95%]: 0; 39) in patients with other transmission risks (p=0.041). Proportions of recent infections were significantly higher in MSM ≤30 years (p=0.019). The mean age was 33.9 (median 34 years) in recent compared with 38.6 years (median: 38 years) in long-standing infections (p=0.011). High-risk behaviour indicated through very low condom use in recently HIV infected MSM could be identified. The results of the pilot study support expectations that the modified application of the method may contribute to improving HIV prevention efforts in Germany. On this basis the Robert Koch Institute implemented a countrywide HIV incidence study to complement HIV surveillance in early 2008. The study is funded by the German Ministry of Health. Data on recent HIV infections and current HIV transmission risks are collected. Design, methods and impact are described in detail

Antikörperreifung in der frühen HIV-Infektion und ihre Anwendung in Inzidenztesten

In dieser Arbeit wurden zwei serologische Teste zur Unterscheidung inzidenter und prävalenter Proben etabliert und validiert, welche auf der Reifung des Immunsystems in der frühen HIV-Infektion basieren. Im BED-ELISA werden anhand von anti-HIV-gp41-spezifischen IgG-Antikörperspiegeln die Proben klassifiziert. Die Aviditäts-Methode (AI) unterscheidet die Bindungsfähigkeit der Antikörper an spezifische Antigene. Das Probenpanel wurde in einem weiteren Inzidenztest, dem IDE-V3-ELISA (Kooperation F. Barin), gemessen welcher den Anstieg der Antikörperreaktivität gegen zwei verschiedene immundominante Epitope nutzt. Wirtsspezifische Marker und virale Eigenschaften wurden untersucht, um Merkmale zu identifizieren, welche die Sensitivität und Spezifität der Teste verbessern könnten. Mit dem BED-ELISA wurde eine Pilotstudie unter Berliner HIV-Patienten durchgeführt. Zur Vereinfachung des Probentransports in Studien wurde der Einfluss einer Filtertrocknung der Plasmaproben auf die Infektiosität von HIV, Stabilität der HIV-RNA und die Antikörperreaktivität im BED-ELISA untersucht. In den Testen wurden inzidente Plasmaproben mit folgenden Sensitivitäten und Spezifitäten richtig klassifiziert: 80% und 86% (BED-ELISA); 74% und 82% (AI); 73% und 84% (IDE-V3). Von allen untersuchten wirtsspezifischen Faktoren korrelierte nur der Gehalt an Antikörpern der IgG3-Subklasse mit der Fehlklassifikation der Proben. Für die Pilotstudie wurden zwischen Feb. 2005 und Nov. 2007 von 132 erstmalig HIV-1 positiv diagnostizierten Patienten Proben genommen und im BED-ELISA analysiert (51% Anteil inzidente Infektionen). Die Antikörperreaktivitäten blieben nach der Filtertrocknung erhalten, so das auf der Grundlage der Ergebnisse eine deutschlandweite Inzidenzstudie mit Filter-getrockneten Plasmaproben geplant wurde, die seit Januar 2008 im Auftrag des BMG zur Verbesserung der Datenlage zur HIV-Inzidenz in Deutschland durchgeführt wird.In this PhD thesis two methods that can differentiate between incident and prevalent infections were established and validated. Both tests are based on the maturation of the immune system during early HIV-infection. The BED-ELISA uses anti-HIV-gp41 specific IgG-antibody levels for differentiation. The avidity method (AI) is based on the binding-capacity of the antibodies to specific antigens in the presence of a chaotropic agent. The sample panel was also evaluated using an additional incidence ELISA, the IDE-V3-ELISA (cooperation with F. Barin). This test is also based on the antibody''s reactivity to two different immune dominant epitopes, allowing incident and prevalent infections to be differentiated. Host specific factors and viral determinants were analysed to provide information that could lead to improvements in the sensitivity and specificity of the incidence tests. With the BED-ELISA a pilot study with HIV-infected patients in Berlin was carried out. The inactivation of HIV-1 after filter-drying of samples, the stability of viral RNA and reactivity of antibodies in the BED-ELISA were analysed to simplify the transport of samples in future studies. Incident plasma samples were identified correctly with following sensitivities and specificity’s: 80% and 86% (BED-ELISA); 74% and 82% (AI); 73% and 84% (IDE-V3). Of all host factors analysed, only the titre of IgG3-antibodies correlated with the incorrect classification of samples. In the pilot study samples from 132 newly diagnosed HIV-positive patients were obtained between February 2005 and November 2007 and analysed in the BED-ELISA (51% proportion of incident infections). It could be shown that filter-drying of plasma samples rendered HIV non-infectious but did not influence antibody reactivity. Based on these results, a German HIV incidence study using filter-dried plasma samples, designed to improve knowledge of HIV-incidence in Germany, was sponsored by the BMG and has been ongoing since January 2008

Piloting second generation HIV surveillance in Berlin, Germany, 2005 - 2007

Men having sex with men (MSM) are by far the transmission-risk-category most affected by HIV in Berlin and were investigated in this pilot-study with the aim to identify detailed risk- and prevention-behaviours in recently infected persons. From November, 2005 - February, 2007, venous blood samples were taken from patients in Berlin aged ≥18 years within 3 months after diagnosis of HIV-infection and tested with BED IgG-capture-ELISA (BED-CEIA) to differentiate between longstanding and recent HIV-infections dating back no longer than 140 days from blood sampling. Data on knowledge, attitudes, behaviour and practices (“KABP-survey”) relating to HIV/AIDS, were collected anonymously by structured patients’ questionnaires, accomplished by demographic data via additional questionnaires filled by the physicians. SPSS 15.0 was used for data analysis. This sub-analysis includes 37 MSM with confirmed recently acquired HIV infection. Mean age was 34 years (20 - 53). Good knowledge on HIV/AIDS in Germany and transmission risks was present in most cases; nevertheless unprotected sexual contacts were indicated by 90% of recently HIV-infected MSM (independent from type of intercourse and partners’ sero-status) with 64% reporting unprotected anal intercourse. Unprotected anal intercourse with a person they knew to be infected with HIV was stated by 19% of cases. In 5% drugs/alcohol and in 48% (n = 18/37) uncertain HIV-related knowledge, hope and beliefs about transmission risks were stated as reasons for unprotected sex. Almost half of recently infected MSM in this pilot-study were infected because hope and beliefs on HIV-transmission-risks had guided their personal decisions on HIV-prevention efforts. Limitations due to a small study population, lack of HIV-negative-tested controls and selection bias should be optimised in future studies; however, the findings have strong implications for amending prevention messages in Germany addressing MSM

Comparison of the Human Immunodeficiency Virus (HIV) Type 1-Specific Immunoglobulin G Capture Enzyme-Linked Immunosorbent Assay and the Avidity Index Method for Identification of Recent HIV Infections▿

The sensitivity and specificity of the human immunodeficiency virus (HIV) type 1-specific immunoglobulin G capture enzyme-linked immunosorbent assay (BED-CEIA) were compared with those of the avidity index method to identify recent HIV infection using a panel of 148 samples (81 patients) representing durations of infection ranging from 0 to 222 weeks. The results from the two tests were similar (sensitivity of 80% versus 74% [P = 0.53]; specificity of 86% versus 82% [P = 0.67])

Conversation about Serostatus decreases risk of acquiring HIV: results from a case control study comparing MSM with recent HIV infection and HIV negative controls

Background: Data on knowledge, attitudes, behaviour and practices (KABP) of persons with recent HIV infection compared to controls with negative HIV test result provide information on current risk patterns and can help to re-focus HIV prevention strategies. Methods: From March 2008 through May 2010, persons newly diagnosed with HIV (cases) and HIV-negative controls were recruited by physicians in Germany. To distinguish recent ( 5 months) infection, dried blood spots from people newly diagnosed with HIV were tested with the BED IgG-capture ELISA. Cases and controls completed a KABP-questionnaire. We compared cases with recent infection and controls among men having sex with men (MSM) regarding reported risk behaviour in the previous 6 months. To detect differences, unadjusted Odds Ratios (OR) were calculated and multivariate analysis was performed. Results: Cases and controls did not differ in terms of knowledge on transmission risks, HIV testing frequency, partnership status, or regarding the frequency of any unprotected sex with partners known to be HIV-positive or assumed to be HIV-negative. Cases more often reported a shorter duration of partnership