Evaluation of HIV/AIDS diagnostics kits and formulation of a testing strategy for Pakistan

Rapid point-of-care (POC) testing for Hepatitis C antibodies in a very high prevalence setting: persons injecting drugs in Tallinn, Estonia

BACKGROUND

Between December 2018 and January of 2019, we evaluated the accuracy of the point-of-care Hepatitis C (HCV) antibody test (POC; OraQuick HCV) used at a community-based needle and syringe exchange program serving persons who inject drugs in Tallinn, Estonia.

METHODS

We compared the results of screening for HCV antibodies by OraQuick (oral swab) and enzyme immunoassay (EIA; blood draw) and assessed test results implications in a high prevalence setting. Findings Of the 100 participants, 88 (88%) had reactive POC test results, and 93 were HCV antibody positive on EIA testing. Sensitivity, specificity and negative predictive value (NPV) for the POC assay with EIA as the relevant reference test were as follows: 94.6% (95% CI 90.0-99.2%), 100% and 58.3% (95% CI 30.4-86.2%). Of the 12 testing, HCV-negative with the POC only 7 (58.3%) were true negatives.

CONCLUSIONS

Oral swab rapid testing HCV screening in this nonclinical setting was sensitive and specific but had unacceptably low NPV. In high prevalence settings, POC tests with high sensitivity and that directly measure HCV RNA may be warranted.

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 4th-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 4th-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.

Evaluation of Blood-Based Antibody Rapid Testing for HIV Early Therapy: A Meta-Analysis of the Evidence

Background

Western blot (WB) assay is considered the gold standard test for HIV infection confirmation. However, it requires technical expertise and is quite time-consuming. WHO recommends blood-based rapid diagnosis to achieve same-day test and treatment. However, this rapid testing strategy has not been promoted worldwide due to inadequate research evaluating the effectiveness of rapid tests (RTs) as an alternative confirmatory HIV test for WB. This study aims to compare the diagnostic performance of rapid HIV tests compared with WB.

Methods

PubMed and Web of Science were searched for publications on rapid HIV tests using blood specimen. A meta-analysis was performed to quantitatively evaluate the diagnostic performance of rapid HIV tests compared with the WB assay in terms of pooled sensitivity, specificity, area under summary receiver operating characteristic (SROC) curve, and diagnostic odds ratio (DOR).

Results

Twenty articles involving 27,343 fresh specimens for rapid HIV tests were included in the meta-analysis. Regarding Capillus HIV-1/HIV-2, the pooled sensitivity, specificity, area under SROC curve, and DOR derived from six studies were 0.999 (95% CI, 0.956-1.000), 0.999 (95% CI, 0.991-1.00), 1.00 (95% CI, 0.99-1.00), and 1.0 × 10⁶ (95% CI, 2.6 × 10⁴-3.9 × 10⁷) compared with the WB assay, respectively. With respect to Determine HIV-1/2, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 1.00 (95% CI, 0.789-1.000), 0.992 (95% CI, 0.985-0.996), 1.00 (95% CI, 0.99-1.00), and 1.8 × 10⁶ (95% CI 406.049-7.8 × 10⁹) compared with the WB assay, respectively. Regarding two-step serial RTs, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 0.998 (95% CI, 0.991-1.000), 0.998 (95% CI, 0.994-0.999), and 1.00 (95% CI 0.99-1.00) compared with the WB assay, respectively.

Conclusion

Our meta-analysis results may provide evidenced-based support for substituting RT for WB. Blood-based rapid HIV tests have comparable sensitivity and specificity to WB for HIV early therapy.

A rapid ultrasound particle agglutination method for HIV antibody detection: Comparison with conventional rapid HIV tests

We present the results of the feasibility and preliminary studies on analytical performance of a rapid test for detection of human immunodeficiency virus (HIV) antibodies in human serum or plasma that is an important advance in detecting HIV infection. Current methods for rapid testing of antibodies against HIV are qualitative and exhibit poor sensitivity (limit of detection). In this paper, we describe an ultrasound particle agglutination (UPA) method that leads to a significant increase of the sensitivity of conventional latex agglutination tests for HIV antibody detection in human serum or plasma. The UPA method is based on the use of: 1) a dual mode ultrasound, wherein a first single-frequency mode is used to accelerate the latex agglutination process, and then a second swept-frequency mode of sonication is used to disintegrate non-specifically bound aggregates; and 2) a numerical assessment of results of the agglutination process. The numerical assessment is carried out by optical detection and analysis of moving patterns in the resonator cell during the swept-frequency mode. The single-step UPA method is rapid and more sensitive than the three commercial rapid HIV test kits analyzed in the study: analytical sensitivity of the new UPA method was found to be 510-, 115-, and 80-fold higher than that for Capillus™, Multispot™ and Uni-Gold™ Recombigen HIV antibody rapid test kits, respectively. The newly developed UPA method opens up additional possibilities for detection of a number of clinically significant markers in point-of-care settings.

Experience of offering HIV rapid testing to at-risk patients in community health centers in eight Chinese cities

Objective

To explore the feasibility of offering HIV counseling and testing in community health centers (CHCs) and to provide evidence for the HIV/AIDS response in China.

Methods

Forty-two CHCs were selected from the eight cities that participated in the study. Rapid testing was mainly provided to: clients seeking HIV testing and counseling (HTC); outpatients with high-risk behavior of contracting HIV; inpatients and outpatients of key departments. Aggregate administrative data were collected in CHCs and general hospitals and differences between the two categories were compared.

Results

There were 23,609 patients who underwent HIV testing, accounting for 0.37% of all estimated clinic visits at the 42 sites (0.03%–4.35% by site). Overall, positive screening prevalence was 0.41% (95% confidence interval [CI] 0.33%–0.49%, range 0.00%–0.98%), which is higher than in general hospitals (0.17%). The identification efficiency was 0.22% (95% CI: 0.16%–0.27%) in pilot CHCs, 3.5 times higher than in general hospitals (0.06%) (Chi square test = 95.196, p<0.001). The percentage of those receiving confirmatory tests among those who screened positive was slightly lower in CHCs (73.7%) than in general hospitals (80.1%) (Chi-square test = 17.472, p<0.001). Composition of clients mobilized for testing was consistent with the usage of basic public health and medical services in CHCs. The rate of patients testing HIV positive was higher among patients from key CHC departments (0.68%) than among high-risk Voluntary Counseling and Testing (VCT) clients (0.56%), those participating in outreach activities (0.41%), pregnant women (0.05%), and surgical patients (0.00%).

Conclusion

This project demonstrates that providing HIV testing services for patients who exhibit high risk behavior has a high HIV case detection rate and that CHCs have the capacity to integrate HTC into routine work. It provides concrete evidence supporting the involvement of CHCs in the expansion of HIV/AIDS testing and case finding.