ABSTRACT
BACKGROUND: Diagnosis of HIV infection is a multistage algorithm. Following screening with 4(th) generation combination immunoassay, confirmation of HIV infection is performed with an antibody assay that differentiates HIV-1 from HIV-2 infection. In the newly updated algorithm, samples that are nonreactive or indeterminate in the differentiation assay are to be tested with an HIV-1 nucleic acid amplification (NAAT) test for resolution. Xpert HIV-1 Qual is a new NAAT assay approved for the identification of HIV infection in whole and dried blood. OBJECTIVES: To assess the performance of Xpert HIV-1 Qual supplementary assay in resolving the clinical status of serum samples reactive by 4(th) generation immunoassays and indeterminate or negative by Geenius HIV-1/2 confirmatory assay. STUDY DESIGN: In a retrospective study, samples from 97 individuals for whom the true HIV-1 status was already known (by follow-up samples) and which were negative or indeterminate by HIV-1/2 Geenius assay were tested with Xpert Qual HIV-1 assay. RESULTS: Xpert Qual assay correctly classified all 97 samples from HIV-1 positive (n=49) and negative (n=48) individuals. The sensitivity and specificity of Xpert Qual when using the true HIV status as a reference were 100% (92.7-100% at 95% confidence interval [CI] and 92.6-100% at 95% CI, respectively). CONCLUSIONS: Applying Xpert Qual HIV-1 assay in the new HIV multi-stage diagnostic algorithm correctly classified 100% of HIV-1 infections including 49 from HIV-1 carriers who have not yet seroconverted. With this assay the total time required for acute HIV diagnosis could be significantly reduced.
Subject(s)
HIV Antibodies/blood , HIV Infections/diagnosis , HIV-1/isolation & purification , Nucleic Acid Amplification Techniques , AIDS Serodiagnosis , Algorithms , Blotting, Western , HIV Infections/blood , HIV Infections/virology , HIV-1/genetics , HIV-1/immunology , HIV-2/immunology , HIV-2/isolation & purification , Humans , Immunoassay , Mass Screening , Reagent Kits, Diagnostic , Retrospective Studies , Sensitivity and SpecificityABSTRACT
We investigated prevalence of hepatitis E virus in a sample of the population of Israel. The overall seroprevalence of antibodies to the virus was 10.6% (95% CI 8.4%-13.0%); age-adjusted prevalence was 7.6%. Seropositivity was associated with age, Arab ethnicity, low socioeconomic status, and birth in Africa, Asia, or the former Soviet Union.
Subject(s)
Hepatitis Antibodies/immunology , Hepatitis E virus/immunology , Hepatitis E/epidemiology , Hepatitis E/immunology , Adolescent , Adult , Aged , Female , Genotype , Hepatitis E/history , Hepatitis E/transmission , Hepatitis E virus/genetics , History, 21st Century , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Israel/epidemiology , Male , Middle Aged , Odds Ratio , Prevalence , Seroepidemiologic Studies , Young AdultABSTRACT
The Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the INNO-LIA HIV 1/2 assay for the confirmation of HIV infection in 198 serum samples reactive to 4th-generation HIV enzyme immunoassays (EIAs). The Geenius assay correctly identified 85% of the samples, compared to 75% identified by the INNO-LIA assay, reduced the number of indeterminate results, and shortened the overall turnaround time.
