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Abstract: Objectives: The detection of HIV seroconverters increased annually since HIV antigen/antibody testing kits have been available widely in South Korea. This study aimed to identify the epidemiological characteristics of HIV seroconverters and their immune level at HIV diagnosis. Method: We analyzed the epidemiological and immunological characteristics of 341 HIV seroconverters among 6,008 HIV-diagnosed individuals from 1999 and 2009. The analysis of immune level and epidemiological factors of HIV seroconverters was conducted by using chi-square test on SAS version 9.1. Results: The seroconverters among newly-identified HIV cases each year increased from 0.5% in 1999 to over 5% or in 2009. The sex ratio of seroconverters was 18:1 (male:female), and 33% were in their 30s, and 28% were in their 20s. Reasons for HIV testing were involvement in voluntary test due to risky behaviors (43%), and health check-up (36%). Discovery of HIV infection occurred primarily in hospitals (84%). Among seroconverters, 55 percent had a CD4 T-cell count of more than 350/μl. Conclusion: Korean HIV seroconverters tended to be younger at diagnosis, diagnosed during a voluntary test, and their CD4+ T-cell counts at HIV diagnosis were higher than those of non-seroconverters all HIV-infected individuals. This study of HIV seroconverters will be important foundational in future studies on HIV incidence, disease progress, and survival rate. [Copyright &y& Elsevier]

Background: The external quality assessment schemes (EQAS) organizer provides a suitable program to monitor and improve the quality of human immunodeficiency virus (HIV) testing laboratories with EQAS panels prepared under various conditions. The aim of the current study was to investigate the effects of human plasma samples on the EQAS results of HIV obtained from hospital-based clinical laboratories. Methods: From 2007 to 2009, HIV EQAS panels consisted of four to six samples that consisted of undiluted positive and negative samples and were provided to laboratories twice per year. Up until the first half EQAS in 2008, EQAS panel materials were obtained by converting acid citrate dextrose treated plasma to serum via chemical treatment with CaCl2. Beginning with the second EQAS in 2008, all materials were prepared without the defibrination process. Results: Approximately 300 HIV clinical laboratories participated in this program. The overall performance of clinical laboratories was shown to be improved when using unrecalcified plasma panels compared with recalcified panels. Significant differences were observed in EIA analyses of plasma for both positive (p<0.001) and negative (p<0.001) samples between the recalcified and unrecalcified groups. Conclusions: Our finding suggested that defibrination status of EQAS panels might affect the results of anti-HIV EQAS of Korean HIV testing laboratories. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The Korea HIV/AIDS cohort was constructed with 18 hospitals that care for HIV-infected individuals in 2006. We compared the epidemiological and immunological characteristics of the cohort registrants with those of the HIV-infected population at the time of HIV diagnosis. Methods: This study was conducted on 5717 people living with HIV/AIDS from 1985 to 2009, of which 789 individuals registered with the Korea HIV/AIDS cohort study. Individuals who had data from initial CD4+ T-cell counts measured within 6 months following HIV diagnosis were selected as study participants to predict the status of disease progression at the time of HIV diagnosis. A total of 2886 patients (50%) were selected from people living with HIV/AIDS, of whom 424 individuals (54%) were cohort registrants. The χ2 test and Wilcoxon rank sum test were used for analysis. Results: The distributions of age, marital status, diagnosed regions, reason for HIV testing, and screening site were similar between the HIV-infected population and the cohort registrants. In 1985–2004, the male ratio for the cohort registrants (94.3%) was significantly higher than that measured for the HIV-infected population (89.5%) (p = 0.0339). With regard to transmission route, homosexual contact of cohort registrants (46.6%) was higher than that of the HIV-infected population (40.1%) (p = 0.022) in 2005–2009. No statistical difference in CD4+ T-cell counts at the time of HIV diagnosis was found between the HIV-infected population and cohort registrants (p = 0.2195). Conclusion: The Korea HIV/AIDS cohort registrants represent the HIV-infected population, and the data collected from this cohort could be used as a foundation for national statistics. [Copyright &y& Elsevier]

Abstract: Background: This report presents HIV External Quality Assessment (EQAS) results by the KCDC from the 17 HIV testing laboratories that also performed HIV-1 western blot testing of the 585 laboratories. Method: The HIV EQAS panel consisted of 10 undiluted plasma samples from donors who were 3 positive, four indeterminate and 3 negative for HIV antibody. The results were analyzed by traditional methods (mean±2 SD), robust statistics (median), and Youden plots (99% coverage). Results: The sensitivities for the HIV antigen and antibody ELISAs were 94.1% and 98.3%, respectively, with the inconsistent 1.7% caused by indeterminate, weakly positive samples. The specificities of HIV antigen and antibody ELISAs were 93.3% and 100%, respectively. The traditional method detected 2 laboratories as outliers for HIV antigen testing and 3 laboratories as outliers for HIV antibody testing. The robust statistics method showed better discrimination of outliers, detecting seven laboratories as outliers for HIV antigen testing and six for HIV antibody testing. The outliers detected by the Youden plot were differentiated as six systematic and 2 random errors. Conclusion: Therefore, the design of reliable EQAS based on HIV panels with varied and specified titers is prerequisites for quality improvement of HIV testing laboratories. [Copyright &y& Elsevier]

This study aimed to provide evaluation information about rapid HIV kits by the anti-HIV External Quality Assessment Schemes (EQAS) panel of the Korea National Institute of Health (KNIH) and the rapid HIV test panel of the US Centers for Disease Control and Prevention (CDC). Each KNIH anti-HIV EQAS panel from 2003 to 2005 consisted of four or five samples of plasma obtained from blood donors with a strong positive or negative reaction to HIV. KNIH delivered each panel to public health centers for analysis of the HIV test results, and the reactivity of the five rapid HIV kits currently used in the Korean market were compared with that of a CDC reference. The analytic sensitivity and specificity of the rapid HIV kits for the KNIH anti-HIV EQAS in 2005 were 99.3 and 99.1%, respectively; in 2004, 98.8 and 97.1%; and in 2003, 94.8 and 95.9%. Five HIV kits from the CDC panel consistently showed positive reactivity for strong positive samples in all kits, but some showed erratic reactivity for weakly positive samples. This is the first report on post-evaluation of rapid HIV kits in the Korean market by an anti-HIV EQAS panel. It was found that the quality of performance of the rapid HIV tests had improved each year but should be interpreted with caution for weakly positive samples.