Comparative evaluation of TRI-DOT Rapid HIV test with fourth-generation ELISA for the detection of human immunodeficiency virus

Evaluation of Two HIV Rapid Diagnostic Tests in a Context of Strains' Genetic Diversity in Mali

The rapid diagnostic tests used in most resource-limited countries offer little specificity in the differentiation of HIV-1, HIV-2, and HIV-1 + 2. World Health Organization (WHO) does periodically evaluate rapid tests in use in the South Countries. Despite the prequalification from WHO, it is necessary at local level to conduct comparative studies between the available tests. To do this in Mali, we conducted a cross-sectional study at the University Teaching Hospital Gabriel Touré and the Research and Training Center (SEREFO) of Bamako on 172 samples from retrospective and prospective studies. The goal of this project was to compare the following rapid tests: "HIV TRI-DOT" and OnSite HIV1/2 Ab Plus Combo Rapid Test for screening HIV-1 and HIV-2 to "ImmunoComb II BiSpot" (gold standard). The sensibility and specificity of "HIV TRI-DOT" for HIV-1 detection were 100% each [95% confidence interval (CI): 87.13-100 and 95.31-100]. Its performance for HIV-2 detection was 95.24% (95% CI: 84.21-98.68) (sensibility) and 100% (95% CI: 72.25-100) (specificity). The positive and negative predictive values were, respectively, 100% (95% CI: 91.24-100) and 83.33% (95% CI: 55.20-95.30). The sensibility and specificity of OnSite HIV1/2 Ab Plus Combo Rapid Test assay performance were 100% (95% CI: 87.13-100 and 95.31-100). Overall, OnSite HIV ½ Ab Combo Rapid Test proved to be a good test for warm countries and does not require refrigeration in these settings. Blood and its products can be used to perform the test, unlike "ImmunoComb II BiSpot" and "HIV TRI-DOT," which must be kept cold and cannot be done with whole blood.

Extensive tests for extermination: Need for incorporation of molecular detection methods of human immunodeficiency virus in screening algorithm in tertiary hospitals in India

Context:

A downward trend is being observed in the incidence of human immunodeficiency virus (HIV) infection in India due to strategic activities of National AIDS Control Organisation (NACO) in the last 24 years. Opt-out testing has consistently shown high seroprevalence in our tertiary care center.

Aim:

This study aims to audit opt-out testing and compare various commercial test kits used to detect HIV seroprevalence in patients in our tertiary care institute and suggest new algorithm for HIV testing in tertiary hospitals in India.

Materials and Methods:

Retrospective analysis of 30,021 samples tested in Department of Immunopathology using opt-out testing delinked from the NACO-sponsored testing for Integrated Counselling and Testing Centre (ICTC) was performed. Study population comprised of presurgery and emergency patients which at the time of our reporting were not included in ICTC testing.

Results:

Microlisa was the first test performed on 76% samples. 1.02% cases were reactive only with Microlisa and negative with other rapid kits hence were reported as negative, according to NACO scheme of reporting. Advanced testing algorithm followed by centre for disease control (CDC) showed that 80% of these 4^th-generation positive and rapid test-negative patients turned out to be acute HIV infections on molecular testing.

Conclusion:

Patients in tertiary referral center constitute high-risk population and should be screened with 4^th-generation enzyme-linked immunosorbent assay which incorporates p24 antigen. Those which are found indeterminate should have molecular testing by nucleic acid amplification test or real-time polymerase chain reaction, as our study has demonstrated that 1.02% of these cases may harbor acute HIV infection.

Seroprevalence of human immunodeficiency virus in north Indian blood donors using third and fourth generation Enzyme linked immunosorbent assay

Background:

The percentage of HIV cases attributable to blood transfusion has decreased significantly in the last decade. The newer 4^th generation Enzyme linked immunosorbent assay (ELISA) has been shown to have increased sensitivity compared to 3^rd generation ELISA.

Objectives:

To estimate the seroprevalence of HIV among blood donors using 4^th generation ELISA assay and to compare it with the 3^rd generation ELISA.

Materials and Methods:

This prospective study involved 10,200 blood donors- 6,800 were voluntary donors (3400-students and 3400-non students) and 3400 were replacement donors. All blood units were tested with 3^rd as well as 4^th generation ELISA. All samples found reactive or in grey zone with either 3^rd or 4^th generation ELISA were retested by Western blot (WB).

Results:

The seroprevalence of HIV was estimated to be 1.37/1000 donations (0.14%) with 3^rd generation ELISA compared to 3.62/1000 donations (0.36%) with 4^th generation ELISA (p>0.05). The seroprevalence of HIV among voluntary donors was estimated to be 1.32/1000 donations (0.13%) with 3^rd generation ELISA and 3.67/1000 donations (0.36%) with 4^th generation ELISA. The prevalence of HIV among replacement donors was 1.47/1000 donations (0.15%) with 3^rd generation ELISA and 3.52/1000 donations (0.35%) with 4^th generation ELISA.

Conclusion:

4^th generation HIV ELISA detects a higher number of seroreactive donors compared to 3^rd generation ELISA. However, larger studies are required with confirmatory tests for both 3^rd and 4^th generation ELISA for making any policy changes.

Performance characteristics of a new rapid immunochromatographic test for the detection of antibodies to human immunodeficiency virus (HIV) types 1 and 2

Diagnostic kits for the detection of human immunodeficiency virus (HIV) antibodies have reached an unprecedented number. But choice of an ideal, cost-effective, and rapid test for HIV infection is of immense value for use in developing countries like India, where resources are limited. In this study we have evaluated the performance characteristics of the rapid immunochromatographic HIV test kit First Response HIV 1-2.O. First, the laboratory archived 450 characterized plasma/serum specimens, which were tested on First Response HIV 1-2.O. Second, a total of 134 consecutive voluntary counseling and testing (VCT) specimens were also tested and positive specimens were further confirmed with HIV TRI-DOT. All these VCT specimens were cross-checked with HIV double-enzyme-linked immunosorbent assay (ELISA) (Murex and Vironostika), and the results were matched. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and efficiency of First Response HIV 1-2.O with the 450 characterized specimens was 100% for HIV-1 with reference assay. The results in the VCT algorithm were correlating with double-ELISA. In the HIV-2 analysis, five HIV-2-positive specimens in First Response HIV 1-2.O were found to be HIV-2-indeterminate on Western blot. HIV TRI-DOT was unable to pick up two HIV-2 Western blot-positive specimens. First Response HIV 1-2.O has several advantages: low-cost (U.S. $0.70); only 10 microL of specimen; involves only two steps; room temperature storage; ability to differentiate HIV-1 and 2; and use of whole blood specimen. Hence this test kit could be suitable for initial screening in the HIV testing algorithm in resource-limited settings. J. Clin. Lab. Anal. 22:178-185, 2008. (c) 2008 Wiley-Liss, Inc.