Cost-Effectiveness of Voluntary HIV Testing Strategies in a Very Low-Prevalence Country, the Republic of Korea

BACKGROUND: The Republic of Korea has a very low prevalence of human immunodeficiency virus (HIV) infection, but the number of new HIV diagnoses has steadily risen, strongly indicating a large number of undetected HIV infections. Thus, it is important for Korean public health authorities to adopt and encourage cost-effective HIV detection tools, such as rapid HIV screening tests. In this study, we aimed to evaluate the cost-effectiveness of enzyme-linked immunosorbent assays (ELISA) and rapid tests in a public health center (PHC) setting. METHODS: We developed a decision analytic model to assess the per-examinee cost and the cost-effectiveness of identifying HIV patients in a PHC setting using two HIV testing strategies: conventional HIV screening by ELISA versus rapid HIV testing. Analysis was performed in two scenarios: HIV testing in an average-risk population and in a high-risk population. RESULTS: Compared to the ELISA, the rapid test was cost-saving and cost-effective. The per-examinee cost was USD 1.61 with rapid testing versus USD 3.38 with ELISA in an average-risk population, and USD 4.77 with rapid testing versus USD 7.62 with ELISA in a high-risk population. The cost of identifying a previously undiagnosed HIV case was USD 26,974 with rapid testing versus USD 42,237 with ELISA in an average-risk population, and USD 153 with rapid testing versus USD 183 with ELISA in a high-risk population. CONCLUSION: Rapid testing would be more cost-effective than using conventional ELISA testing for identifying previously undiagnosed HIV-infected cases in Korea, a country with extremely low HIV prevalence.

Analysis of the Patients with Indeterminate Results by Anti-HIV Western Blot Assay: Experience of a University Hospital During Recent 5 Years in Korea / 임상검사와정도관리

BACKGROUND: Interpretation of indeterminate results by anti-HIV Western blot assay, which is currently used as a confirmatory test for HIV infection, can be usually difficult. We analyzed outcomes of the patients with indeterminate results by anti-HIV Western blot. METHODS: Medical records of patients, who were indeterminate by the anti-HIV Western blot assay in a university hospital during recent 5 years, were retrospectively reviewed. HIV screening test was performed by chemiluminescent immunoassay autoanalyzer (Abbot Laboratories, USA) with HIV Ag/Ab Combo kits. Confirmatory Western blot assay for the positive samples by HIV screening test was committed to the Korean National Institute of Health. RESULTS: A total of 202,639 specimens were tested for HIV screening during the period, and 644 (0.32%) sera showed positive results. Among these, 46 (7.1%) cases were indeterminate by the Western blot, which were from 20 patients, and 13 of them converted to be anti-HIV positive, and 3 were lost to follow-up. Another four patients were turned out to be negative for HIV infection, including two neonates from HIV-positive mothers receiving antiviral treatment during pregnancy. CONCLUSIONS: Most of the patients who showed Western blot-indeterminate results converted to HIV positive after follow-up. Thus, careful monitoring of patients with indeterminate Western blot results should be essential.

Evaluation of a Screening Test kit of Simultaneous p24 Antigen and Anti-HIV1/2 Detection in Diagnostic Aspect / 대한임상병리학회지

BACKGROUND: Human immunodeficiency virus(HIV) is the causative agent of acquired immune deficiency syndrome(AIDS). Current diagnosis of HIV infection relies on the detection of anti-HIV antibodies by ELISA. Recently, simultaneous detection kit of p24 antigenemia and anti-HIV1/anti-HIV2 antibodies were developed. The aim of this study was to evaluate the diagnostic kit of simultaneous detection with p24 antigen and anti-HIV1/2 in diagnostic aspect. METHODS: Eight hundred and four sera which were obtained between July 1999 and August 1999 and 110 sera from 54 patients diagnosed as HIV infection were included. One lot of panels composed of consecutive sera obtained from known HIV-infected patients was included. The detection of anti-HIV1/2 antibodies was done by Genedia HIV1/2 ELISA 3.0 kit(Greencross, Seoul, Korea) and Enzygnost anti-HIV1/2 Plus(Behringwerke, Marburg, Germany). The simultaneous detection of p24 antigenemia and anti-HIV1/2 antibodies was done with VIDAS DUO kit(bioMerieux, Lyon, France). The Vironostika HIV-1 antigen kit was used for detection of p24 antigen. The HIV RNA PCR and anti-HIV western blot assay were also performed to confirm the test results in discrepant cases. RESULTS: The simultaneous detection kit showed 100% sensitivity and 99.6% specificity. The possibility of earlier diagnosis than conventional anti-HIV1/2 EIA was also suggested by the results obtained with a group of consecutive panel sera infected with HIV. CONCLUSION: The simultaneous p24 antigen and anti-HIV1/2 detectin kit can be applied as a clinical screening test as a substitution of conventional anti-HIV1/2 EIA, and there is a probable gain especially in early diagnosis.