Evaluation of a commercial enzyme immunoassay for HIV screening in urine.
ABSTRACT A cross-sectional study was conducted to evaluate the utility of a commercial enzyme immunoassay (EIA) as a screening test for detecting HIV-1 antibody in urine in a population at risk for HIV infection in Catalonia, Spain. Paired urine and serum samples were collected consecutively from 99 patients who attended two drug-dependency treatment centres and 151 patients who attended a sexually transmitted diseases (STD) clinic in Barcelona. Antibodies against HIV in urine samples were detected using the Calypte HIV-1 Urine EIA (Calypte Biomedical Corporation, Berkeley, CA, USA) and confirmed by urine-based Western blot (WB) analysis. Sera were analysed using Bioelisa HIV-1+2 EIA (Biokit Laboratories, Barcelona, Spain), and the results were verified using serum-based WB analysis. Results of both urine and serum testing were available for 246 of 250 participants. For 52 individuals the results of both urine and serum testing were positive and for five the results were discordant (2 with urine-negative/serum-positive results and 3 with urine-positive/serum-negative results). The respective sensitivity and specificity values obtained for the urine EIA were 100% and 96.2% for intravenous drug users (IDUs) and 80% and 99.3% for persons attending the STD clinic. According to the 1997 UNAIDS/WHO strategy I recommendations, these values are acceptable for surveillance purposes, particularly in populations with a high prevalence of HIV infection.
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ABSTRACT: Within the framework of hepatitis C virus (HCV) prevalence monitoring, we evaluated oral fluid (OF), which is richer in IgG than whole saliva, as a possible alternative to serum for the detection of HCV antibodies. Paired OF and serum samples were collected from 90 individuals, including 45 HCV-positives and 45 HCV-negatives. The detection of HCV antibodies in both serum and OF was performed using the Ortho HCV 3.0 SAVe enzyme-linked immunosorbent assay (ELISA) (Ortho-Clinical Diagnostics, Inc., Raritan, NJ), but a modified, more sensitive protocol was used to process OF. The sensitivity and specificity of this assay were 86.67% (95% confidence interval (CI): 72.51-94.46%) and 100% (95% CI: 90.20-99.80%) in OF and 100% in serum. The correlation obtained between both types of clinical specimens was excellent (k: 0.87, 95% CI: 0.66-1.07). However, the negative predictive value (NPV) of the assay in OF decreased with the prevalence of HCV infection in the population studied. Our results suggest that the modified Ortho HCV 3.0 SAVe ELISA is suitable for the detection of HCV antibodies in OF for epidemiological studies. Using this assay, we observed an unadjusted anti-HCV prevalence of 78.6% among a population of intravenous drug users; when adjusted to account for assay sensitivity, this prevalence may be closer to 90%.European Journal of Clinical Microbiology 03/2008; 27(2):121-6. DOI:10.1007/s10096-007-0408-z · 2.54 Impact Factor
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ABSTRACT: Many diagnostic methods for sexually transmitted infections (STIs) have been developed. Because various infection agents are associated with STIs, and because infected persons sometimes show no symptoms, the diagnosis of STIs using nucleic acid amplification tests(NAATs) has required not only simultaneous multi-targeting, but also sensitive detection. Here, we compare microarray and real-time PCR for the detection of three common STIs agents, Ureaplasma urealyticum, Mycoplasma genitalium, and Chlamydia trachomatis, using human urine samples. The detection results showed that microarray and real-time PCR technology are both effective tools for the detection of STI agents. In conclusion, real-time PCR detection offers more sensitivity and specificity than microarray, because of the quantitative method employed. But, microarray offers better performance, in terms of high-throughput and simultaneous multi-targeting.BioChip journal 03/2013; 7(1). DOI:10.1007/s13206-013-7111-1 · 1.05 Impact Factor