Elke Faatz

Introduction of HIV-1 subtypes C, E and A into Austria

BACKGROUNDnDifferent subtypes of HIV-1 are prevalent in various geographical regions. Knowledge of their distribution is of importance with respect to possible differences in biological properties (such as reported for subtype E) as well as to diagnostic problems that may arise when specific subtypes are not recognized by standard serological assays.nnnOBJECTIVESnThe objectives of this study were to investigate the presence of the five major subtypes of HIV-1 (A-E) in the Austrian population and to estimate the prevalence of the individual subtypes in different risk groups.nnnSTUDY DESIGNnSerum samples from 88 HIV-1 positive patients were tested for the presence of subtype-specific antibodies using a peptide ELISA.nnnRESULTSnThe majority of the patients were shown to be infected with HIV-1 subtype B, but infections with subtypes A, C, and E were also detected in the Austrian population, primarily in the heterosexual transmission group. While subtypes A and C were probably imported from different African countries, subtype E appears to have been introduced by sex tourists returning from Thailand.nnnCONCLUSIONnIntroduction of HIV subtypes other than B from Africa and Asia into Austria has already occurred and will certainly increase within the next few years.

Analysis of immunoassays to detect antibodies to hepatitis A virus (anti-HAV) and anti-HAV immunoglobulin M

Two newly developed anti-HAV tests were assessed, using a total of 1835 sera. These two tests are being distributed under the trademarks Enzymun-Test anti-HAV and Enzymun-Test IgM anti-HAV. The anti-HAV test was compared to anti-HAV tests from other manufacturers and featured a high sensitivity combined with a high level of reproducibility and specificity. In terms of sensitivity, reproducibility and specificity, the IgM test proved to be comparable to other IgM anti-HAV tests used for the diagnosis of acute type A hepatitis. Combining both tests was shown to be useful to recognize an acute or past hepatitis A virus infection. In addition, the high sensitivity of the anti-HAV test makes this test extremely useful to assess the immunoresponse to the hepatitis A vaccine.

Boehringer Mannheim modular test concepts in HIV and hepatitis immunoassays

Anti-HIV-antibody and hepatitis C virus (HCV)-antibody screening tests have to be able to detect a variety of virus antibodies. On the other hand, HIV-antigen specific antibody tests that detect only one kind of antibody are needed for prognosis of disease or for distinguishing infection by different virus subtypes. Usually in an enzyme-linked immunosorbent assay for each individual test an individual solid phase has to be created. For our Boehringer Mannheim Enzymun-Test Diagnostics Assay we used a single universal biotin-binding solid phase in all tests and biotin-labeled specific antigens for the individual tests. The modular system for the antibody tests is a convenient tool for the development of a broad test menu for different viruses. We show that the modular system is suited for screening tests for HIV1, HIV2, or HCV antibodies, as as well as for virus typing or for detection of HIV/p24-specific antibodies in a quantitative assay with high precision.