Indeterminate human immunodeficiency virus Western blot profiles in ethiopians with discordant screening-assay results

Rate of HIV Seroconversion Among Seronegative Male Partners Living with HIV Positive Women in Addis Ababa, Ethiopia, 2019: A Retrospective Cohort Study

Objective

This study aimed to assess rate of HIV seroconversion and predictors among seronegative male partners living with HIV-positive women in Addis Ababa, Ethiopia, 2019.

Methods

Institutional-based retrospective cohort was used to conduct the study. All eligible 227 sample medical records were used for the study. Kaplan–Meier analysis was used to estimate seroconversion time. Cox proportional-hazard regression was used to identify predictor variables.

Results

In this study, 227 seronegative male partners living with HIV-positive women were followed for 60 months retrospectively and 38 (16.7%) seroconversion was observed. The overall seroconversion rate was 6.4 (95%CI: 4.64–8.76) per 100 person-year observation. Time of antiretroviral therapy (ART) initiation, CD4 level, condom use, and having history of pregnancy after being diagnosed as discordant were identified significant predictors of seroconversion.

Conclusion

The risk of HIV transmission from seropositive partner to seronegative partner in a discordant couple is poorly controlled. Seronegative partners in discordant a couple can be seropositive at any time with influence of predictors unless proper protective measures, counseling, and follow-up are given emphasis.

HIV serologically indeterminate individuals: Future HIV status and risk factors

BACKGROUND

Indeterminate HIV test results are common, but little is known about the evolution of indeterminate serology and its sociodemographic and behavioral correlates. We assessed future HIV serological outcomes for individuals with indeterminate results and associated factors in Rakai, Uganda.

METHODS

115,944 serological results, defined by two enzyme immunoassay (EIAs), among 39,440 individuals aged 15-49 years in the Rakai Community Cohort Study were assessed. Indeterminate results were defined as contradictory EIAs. Modified Poisson regression models with generalized estimating equations were used to assess prevalence ratios (PRs) of subsequent HIV serological outcomes and factors associated with HIV indeterminate results.

RESULTS

The prevalence of HIV serologically indeterminate results was 4.9%. Indeterminate results were less likely among women than men (adjPR 0.76, 95% CI 0.71,0.81), in unmarried participants than married participants (adjPR 0.92, 95% CI 0.85,99), and in individuals with primary (adjPR 0.90, 95% CI 0.80,1.02), secondary (adjPR 0.83, 95% CI 0.73,0.96) and post-secondary (adjPR 0.75, 95% CI 0.60,0.94) education, relative to no education. The proportions of persons with indeterminate results progressing to HIV positive, negative or indeterminate results in subsequent visits was 5%, 71% and 24%, respectively.

CONCLUSION

HIV serologically indeterminate results were associated with gender and marital status. HIV surveillance programs should develop a protocol for reporting individuals with mixed or persistently indeterminate HIV results on multiple follow-up visits. Most indeterminate results became HIV-negative over time, but follow-up is still needed to detect positive serologies.

Evaluation of HIV testing algorithms in Ethiopia: the role of the tie-breaker algorithm and weakly reacting test lines in contributing to a high rate of false positive HIV diagnoses

Background

In Ethiopia a tiebreaker algorithm using 3 rapid diagnostic tests (RDTs) in series is used to diagnose HIV. Discordant results between the first 2 RDTs are resolved by a third ‘tiebreaker’ RDT. Médecins Sans Frontières uses an alternate serial algorithm of 2 RDTs followed by a confirmation test for all double positive RDT results. The primary objective was to compare the performance of the tiebreaker algorithm with a serial algorithm, and to evaluate the addition of a confirmation test to both algorithms. A secondary objective looked at the positive predictive value (PPV) of weakly reactive test lines.

Methods

The study was conducted in two HIV testing sites in Ethiopia. Study participants were recruited sequentially until 200 positive samples were reached. Each sample was re-tested in the laboratory on the 3 RDTs and on a simple to use confirmation test, the Orgenics Immunocomb Combfirm® (OIC). The gold standard test was the Western Blot, with indeterminate results resolved by PCR testing.

Results

2620 subjects were included with a HIV prevalence of 7.7%. Each of the 3 RDTs had an individual specificity of at least 99%. The serial algorithm with 2 RDTs had a single false positive result (1 out of 204) to give a PPV of 99.5% (95% CI 97.3%-100%). The tiebreaker algorithm resulted in 16 false positive results (PPV 92.7%, 95% CI: 88.4%-95.8%). Adding the OIC confirmation test to either algorithm eliminated the false positives. All the false positives had at least one weakly reactive test line in the algorithm. The PPV of weakly reacting RDTs was significantly lower than those with strongly positive test lines.

Conclusion

The risk of false positive HIV diagnosis in a tiebreaker algorithm is significant. We recommend abandoning the tie-breaker algorithm in favour of WHO recommended serial or parallel algorithms, interpreting weakly reactive test lines as indeterminate results requiring further testing except in the setting of blood transfusion, and most importantly, adding a confirmation test to the RDT algorithm. It is now time to focus research efforts on how best to translate this knowledge into practice at the field level.

Trial registration

Clinical Trial registration #: NCT01716299

Social problems of indeterminate and false positive hiv test results among clients attending a nigerian hiv treatment clinic

Increased availability of Human Immunodeficiency Virus (HIV) screening test and more public enlightenment have resulted in more people coming forward to access counseling and testing at the HIV counseling and testing centers in Nigeria. Some of the clients however obtained indeterminate and false positive results leading to emotional disturbance and occasionally, dilemma to the attending physician. This article/case series looked at some of these situations and discussed how they were attended to.

Early detection of human immunodeficiency virus type 1-specific B-lymphocyte-derived antibodies in a high-risk population

Diagnosis of acute human immunodeficiency virus (HIV) infection, a key driver of the HIV epidemic, remains a public health challenge. The PlasmAcute technology offers an opportunity to detect early anti-HIV antibody responses. B lymphocytes (B cells) were isolated from the blood of seronegative miners in South Africa by using the PlasmAcute method. B-cell lysates and paired sera were tested for anti-HIV-1 antibodies by two different enzyme-linked immunosorbent assays; immunoreactivity was confirmed by Western blotting. All volunteers were tested for HIV type 1 (HIV-1) viral load, p24 antigen, and CD4 count. Sera from HIV-seronegative men who had positive viral loads and were positive for p24 antigen were retested for anti-HIV antibodies after immune complex dissociation. Anti-HIV antibodies were detected in lysates from 16/259 subjects without immunoreactivity in paired sera. Four subjects, one of whom had a positive viral load initially, subsequently seroconverted. Six subjects showed transient anti-HIV-1 antibodies in the lysates and tested negative for all markers at the follow-up. Five subjects without follow-up data initially had lysate-positive/serum-negative samples, and these cases were classified as inconclusive. One subject had lysate antibodies and a detectable viral load but was seronegative at follow-up. In conclusion, lysate-derived anti-HIV-1 B-cell antibodies can be detected prior to seroconversion and earlier than or contemporary with HIV-1 RNA detection.

The evaluation of a rapid in situ HIV confirmation test in a programme with a high failure rate of the WHO HIV two-test diagnostic algorithm

Background

Concerns about false-positive HIV results led to a review of testing procedures used in a Médecins Sans Frontières (MSF) HIV programme in Bukavu, eastern Democratic Republic of Congo. In addition to the WHO HIV rapid diagnostic test algorithm (RDT) (two positive RDTs alone for HIV diagnosis) used in voluntary counselling and testing (VCT) sites we evaluated in situ a practical field-based confirmation test against western blot WB. In addition, we aimed to determine the false-positive rate of the WHO two-test algorithm compared with our adapted protocol including confirmation testing, and whether weakly reactive compared with strongly reactive rapid test results were more likely to be false positives.

Methodology/Principal Findings

2864 clients presenting to MSF VCT centres in Bukavu during January to May 2006 were tested using Determine HIV-1/2® and UniGold HIV® rapid tests in parallel by nurse counsellors. Plasma samples on 229 clients confirmed as double RDT positive by laboratory retesting were further tested using both WB and the Orgenics Immunocomb Combfirm® HIV confirmation test (OIC-HIV). Of these, 24 samples were negative or indeterminate by WB representing a false-positive rate of the WHO two-test algorithm of 10.5% (95%CI 6.6-15.2). 17 of the 229 samples were weakly positive on rapid testing and all were negative or indeterminate by WB. The false-positive rate fell to 3.3% (95%CI 1.3–6.7) when only strong-positive rapid test results were considered. Agreement between OIC-HIV and WB was 99.1% (95%CI 96.9–99.9%) with no false OIC-HIV positives if stringent criteria for positive OIC-HIV diagnoses were used.

Conclusions

The WHO HIV two-test diagnostic algorithm produced an unacceptably high level of false-positive diagnoses in our setting, especially if results were weakly positive. The most probable causes of the false-positive results were serological cross-reactivity or non-specific immune reactivity. Our findings show that the OIC-HIV confirmation test is practical and effective in field contexts. We propose that all double-positive HIV RDT samples should undergo further testing to confirm HIV seropositivity until the accuracy of the RDT testing algorithm has been established at programme level.