Indeterminate rapid HIV-1 test results among antenatal and postnatal mothers

Longitudinal patterns in indeterminate HIV rapid antibody test results: a population-based, prospective cohort study

Rapid HIV tests are critical to HIV surveillance and universal testing and treatment programs. We assessed longitudinal patterns in indeterminate HIV rapid test results in an African population-based cohort. Prospective HIV rapid antibody test results, defined by two parallel rapid tests, among participants aged 15-49 years from three survey rounds of the Rakai Community Cohort Study, Uganda, from 2013 to 2018, were assessed. An indeterminate result was defined as any weak positive result or when one test was negative and the other was positive. A total of 31,405 participants contributed 54,459 person-visits, with 15,713 participants contributing multiple visits and 7,351 participants contributing 3 visits. The prevalence of indeterminate results was 2.7% (1,490/54,469). Of the participants with multiple visits who initially tested indeterminate (n = 591), 40.4% were negative, 18.6% were positive, and 41.0% were indeterminate at the subsequent visit. Of the participants with two consecutive indeterminate results who had a third visit (n = 67), 20.9% were negative, 9.0% were positive, and 70.2% remained indeterminate. Compared to a prior negative result, a prior indeterminate result was strongly associated with a subsequent indeterminate result [adjusted prevalence ratio, 23.0 (95% CI = 20.0-26.5)]. Compared to men, women were more likely to test indeterminate than negative [adjusted odds ratio, 2.3 (95% CI = 2.0-2.6)]. Indeterminate rapid HIV test results are highly correlated within an individual and 0.6% of the population persistently tested indeterminate over the study period. A substantial fraction of people with an indeterminate result subsequently tested HIV positive at the next visit, underscoring the importance of follow-up HIV testing protocols.IMPORTANCERapid HIV tests are a critical tool for expanding HIV testing and treatment to end the HIV epidemic. The interpretation and management of indeterminate rapid HIV test results pose a unique challenge for connecting all people living with HIV to the necessary care and treatment. Indeterminate rapid HIV test results are characterized by any weak positive result or discordant results (when one test is negative and the other is positive). We systematically tested all participants of a Ugandan population-based, longitudinal cohort study regardless of prior test results or HIV status to quantify longitudinal patterns in rapid HIV test results. We found that a substantial fraction (>15%) of participants with indeterminate rapid test results subsequently tested positive upon follow-up testing at the next visit. Our findings demonstrate the importance of follow-up HIV testing protocols for indeterminate rapid HIV test results.

Rituals of care: Strategies adopted by HIV testers to avoid misdiagnosis in rapid HIV testing in Zimbabwe

A growing number of studies highlight high levels of misdiagnosis in the scale-up of HIV rapid testing programmes, which often remain invisible to individual testers. Drawing on interviews with HIV testers and observations in four health facilities in Zimbabwe, we show that testers navigated the translation of the standardised, dis-embodied norms of laboratory-based testing into the body work of point-of-care testing through ritualisation of laboratory-practices in their daily clinical work. Yet, this was interrupted through the challenging work conditions the testers face. They ritualised careful procedures, forcing themselves to focus even if queues were long, and making quality assurance procedures part of their daily routine. They actively tried to reduce their workloads and double-checked and discussed unexpected results, especially when a test result did not match their evaluation of clients' circumstances or clinical status. This helped not only to increase confidence in the authenticity of their diagnosis, but also to share responsibility for potential errors. Existing approaches to tackle the problem of misdiagnosis through quality assurance (QA) procedures mainly focus on adjusting individual testers' performance and ensuring that basic testing resources were present, thus falling short of creating a work environment that is conducive to high quality testing.

Use of Point-of-Care Nucleic Acid Tests Beyond Early Infant Diagnosis of HIV: A Retrospective Case Review in Lesotho

BACKGROUND

Rapid diagnostic tests (RDTs) for HIV antibodies remain the primary method of diagnosis of HIV in individuals over age 18 months in Lesotho. Although antibody tests have high sensitivity and specificity, up to 2.3% of serial two-test algorithms can have discrepant results between RDTs. In the case of inconclusive RDT results, Lesotho guidelines at the time of this study recommended either repeat testing with the same RDT algorithm after 14 days or immediately collect a blood sample to be sent for laboratory-based polymerase chain reaction testing. Point-of-care qualitative nucleic acid tests (POC qual NAT) may have benefits in rapidly resolving these inconclusive results, particularly when compared with repeating RDTs later or conventional polymerase chain reaction testing at the National Reference Laboratory.

SETTING

Hospitals and clinics at 29 locations throughout Lesotho that had access to point-of-care nucleic acid testing.

METHODS

Retrospective case review.

RESULTS

We identified 100 testing records where POC qual NAT was used to resolve inconclusive RDTs per Lesotho guidelines. Eighty-nine percent of patients received their results in a median of one day from their inconclusive RDT result (interquartile range 0-7 days). Sixty-eight patients (68%) were determined to be HIV positive based on POC nucleic acid tests (NATs), of which 54 (79%) were started on antiretroviral therapy (ART). Median time from inconclusive RDT result to initiation of ART therapy was 2 days (interquartile range 0-14 days). Three patients in this review were pregnant at the time of testing; one was HIV positive by POC qual NAT and was started on ART therapy the same day.

CONCLUSION

As the availability of POC qual NAT platforms increases, they may serve as feasible options for rapid resolution of inconclusive results and initiation of ART, particularly in populations with high risk of imminent transmission.

Uncertainties, work conditions and testing biases: Potential pathways to misdiagnosis in point-of-care rapid HIV testing in Zimbabwe

Disconcerting levels of misdiagnosis are common in point-of-care rapid HIV testing programmes in sub-Saharan Africa. To investigate potential pathways to misdiagnosis, we interviewed 28 HIV testers in Zimbabwe and conducted weeklong observations at four testing facilities. Approaching adherence to national HIV testing algorithms as a social and scripted practice, dependent on the integration of certain competences, materials and meanings, our thematic analysis revealed three underlying causes of misdiagnosis: One, a lack of confidence in using certain test-kits, coupled with changes in testing algorithms and inadequate training, fed uncertainties with some testing practices. Two, difficult work conditions, including high workloads and resource-depleted facilities, compounded these uncertainties, and meant testers got distracted or resorted to testing short-cuts. Three, power struggles between HIV testers, and specific client-tester encounters created social interactions that challenged the testing process. We conclude that these contexts contribute to deviances from official and recommended testing procedures, as well as testing and interpretation biases, which may explain cases of misdiagnoses. We caution against user-error explanations to misdiagnosis in the absence of a broader recognition of how broader structural determinants affect HIV testing practices.

HIV testing: current practice and future directions

New approaches to expanding HIV testing and effective treatment and the wider availability of rapid testing technology have created new opportunities for achieving national and global HIV testing goals. In spite of HIV testing expansion in many settings, growing evidence of the prevention benefits of HIV testing, and the development of new, cost-effective approaches to HIV testing service provision, formidable obstacles to HIV testing expansion persist. Inequitable testing coverage exists within and across countries. While the proportion of people with HIV aware of their status is about 80% in the U.S., the majority of HIV-infected persons in Africa are unaware of their status. Testing of most-at-risk populations, couples, children, and adolescents pose still unresolved policy and programmatic challenges. Future directions for HIV testing include rapid testing technology and detection of acute HIV infection, self-testing expansion, and partner notification. Expanded routine HIV screening and widespread testing is a public health imperative to reach national and international HIV prevention and treatment goals.