The effect of the Universal Test and Treat policy uptake on CD4 count testing and incidence of opportunistic infections among people living with HIV infection in Cameroon: a retrospective analysis of routine data

Background

Cameroon adopted and started implementing in 2016, the 'universal test and treat' (UTT) guidelines to fast-track progress towards the 95-95-95 ambitious targets to end the HIV epidemic. UTT has shown inconsistent results elsewhere and has not yet been assessed in Cameroon. We aimed to evaluate the effectiveness of this novel approach on the quality of care and health outcomes of people living with HIV (PLHIV).

Methods

A retrospective cohort design was conducted at The Nkongsamba Regional Hospital, using routine clinical service delivery data to measure uptake levels of UTT and CD4 testing, and to compare the incidence of opportunistic infections (OI) between PLHIV initiated on ART based on the "Universal Test and Treat" strategy and those initiated on ART based on the standard deferred approach between 2002 and 2020. Kaplan Meier plots and log-rank tests were used to compare OI events between the pre-UTT and post-UTT eras. The Cox regression model was used to screen for factors independently associated with the risk of acquisition of OI.

Results

The uptake of UTT ranged from 39.1% to 92.8% while baseline CD4 count testing reduced drastically from 89.4% to 0.4% between 2016 to 2020 respectively. The median delay in ART initiation declined significantly from 21 days (IQR: 9 - 113) in the pre-UTT era to the same day of diagnosis (IQR: 0 - 2) in the UTT era (p < 0.001). The incidence of all OI events reported was over five times higher during the UTT era than in the pre-UTT era [aHR = 5.55 (95% CI: 3.18 - 9.69), p < 0.001].

Conclusion

The UTT policy has been effectively rolled out and has contributed to improved access to rapid and immediate ART initiation, but a higher incidence of OIs was observed with a rollback of baseline CD4 testing. We advocate for a return to routine baseline CD4 measurement to identify PLHIV who should benefit from interventions to prevent OIs for optimal outcomes under the UTT approach.

Modelling the impact of CD4 testing on mortality from TB and cryptococcal meningitis among patients with advanced HIV disease in nine countries

INTRODUCTION

Despite antiretroviral therapy (ART) scale-up among people living with HIV (PLHIV), those with advanced HIV disease (AHD) (defined in adults as CD4 count <200 cells/mm3 or clinical stage 3 or 4), remain at high risk of death from opportunistic infections. The shift from routine baseline CD4 testing towards viral load testing in conjunction with "Test and Treat" has limited AHD identification.

METHODS

We used official estimates and existing epidemiological data to project deaths from tuberculosis (TB) and cryptococcal meningitis (CM) among PLHIV-initiating ART with CD4 <200 cells/mm3 , in the absence of select World Health Organization recommended diagnostic or therapeutic protocols for patients with AHD. We modelled the reduction in deaths, based on the performance of screening/diagnostic testing and the coverage and efficacy of treatment/preventive therapies for TB and CM. We compared projected TB and CM deaths in the first year of ART from 2019 to 2024, with and without CD4 testing. The analysis was performed for nine countries: South Africa, Kenya, Lesotho, Mozambique, Nigeria, Uganda, Zambia, Zimbabwe and the Democratic Republic of Congo.

RESULTS

The effect of CD4 testing comes through increased identification of AHD and consequent eligibility for protocols for AHD prevention, diagnosis and management; algorithms for CD4 testing avert between 31% and 38% of deaths from TB and CM in the first year of ART. The number of CD4 tests required per death averted varies widely by country from approximately 101 for South Africa to 917 for Kenya.

CONCLUSIONS

This analysis supports retaining baseline CD4 testing to avert deaths from TB and CM, the two most deadly opportunistic infections among patients with AHD. However, national programmes will need to weigh the cost of increasing CD4 access against other HIV-related priorities and allocate resources accordingly.

Longitudinal impact of compliance with routine CD4 monitoring on all cause deaths among treated people with HIV in China

Keeping adherence to the continuous and standardized CD4 follow-up monitoring service is of great significance to the control of disease progression and the reduction of avoidable mortality for HIV-infected patients. As non-communicable diseases (NCDs) have become main causes of deaths for people with HIV (PWH) in the era of combination antiretroviral therapy (cART), how and to what extent does adherence to routine CD4 monitoring differentially impact on AIDS-related versus NCDs-related deaths in low- and middle-income countries (LMIC) remains elucidated. A CD4 test index was developed by dividing the actual number of received CD4 tests by the theoretical number of CD4 tests that should have been performed according to national treatment guidelines during the study period, with an index value of 0.8-1.2 reflecting compliance. From 1989 to 2020, 14,571 adults were diagnosed with HIV infection in Dehong Prefecture of Yunnan province in Southwestern China, 6,683 (45.9%) PWH had died with the all-cause mortality of 550.13 per 10,000 person-years, including 3,250 (48.6%) AIDS-related deaths (267.53 per 10,000 person-years). Among patients on cART, the median CD4 test index was 1.0 (IQR 0.6-1.3), and 35.2% had a CD4 test index less than 0.8. Cox proportional hazards regression analysis indicated that PWH with CD4 test index at 0.8-1.2 were at the lowest risk of both AIDS-related (aHR = 0.06; 95%CI: 0.05-0.07) and NCDs-related (aHR = 0.13; 95%CI: 0.11-0.16)deaths. Adherence to routine CD4 monitoring is critical for reducing both AIDS-related and NCDs-related mortality of PWH. An appropriate (once or twice a year) rather than an unnecessarily higher frequency of routine CD4 testing could be most cost-effective in reducing mortality in LMIC.

How Will New Guidelines Affect CD4 Testing in Veterans With HIV?

BACKGROUND

Guidelines now recommend limited use of routine CD4 cell count testing in human immunodeficiency virus (HIV)-infected patients with successful viral control who are not immunocompromised.

METHODS

CD4 and viral load tests for patients receiving HIV care from the US Department of Veterans Affairs during 2009-2013 were evaluated to determine trends in CD4 testing frequency and the number, cost, and results of CD4 tests considered optional under the guidelines.

RESULTS

There were 28 530 individuals with sufficient testing to be included. At the time of the last CD4 test, 19.8% of the cohort was eligible for optional monitoring and 15.6% for minimal monitoring. CD4 testing frequency declined by 10.8% over 4 years, reducing the direct cost of testing by US$196 000 per year. Full implementation of new treatment guidelines could reduce CD4 testing a further 28.9%, an additional annual savings of US$600 000. CD4 tests conducted during periods of potentially reduced monitoring were rarely <200 cells/µL: 1.1% of the tests conducted when minimal monitoring was recommended and just 0.3% of tests conducted when optional monitoring was recommended were less than this value.

CONCLUSIONS

Reduced CD4 monitoring of HIV-infected patients would result in modest cost savings and likely reduce patient anxiety, with little or no impact on the quality of care. Veterans Affairs has made substantial progress in reducing the frequency of optional CD4 testing, but further reductions may still be warranted.

Automation for clinical CD4 T-cell enumeration, a desirable tool in the hands of skilled operators

BACKGROUND

Automation in HIV clinical flow cytometry when appropriately applied brings considerable standardisation benefits. The Canadian Immunology Quality Assessment Program (CIQAP) detected situations where operators did not manually override automated software in the event of improper output on the Epics XL and FC500 CD4 immunophenotyping platforms. The automated gating algorithm identifies lymphocytes using a double gate strategy based on CD45 × side scatter (SS) gating and a light scatter FS × SS gate known to fail with sub optimal specimens.

METHOD

To generate correct interpretation and results CIQAP introduced a simple protocol modification, bypassing the light scatter gate to include all cells characterized by the CD45 gate. Seventeen problem cases were reanalysed for both absolute and relative T-cell subsets accuracy and compared to the CIQAP group mean values. Results were found to be associated with the percentage of lymphocytes excluded by the automated light scatter gate.

RESULTS

The modified manual protocol resolved poor performance in 14 instances out of 17 problem cases. It was found to improve accuracy when the light scatter gate excluded greater than 5% of the cells. The remaining three cases had a lymphocyte recovery of greater than 94.6% in the original automated analysis.

CONCLUSION

There is a risk in relying solely on automated gating procedures when using the Epics XL and FC500 CD4 immunophenotyping platforms. Laboratory managers have the responsibility to intervene when required. EQA providers are equally responsible to alert the clinical laboratories of the need to update operator training to deal with stressed specimens. © 2016 International Clinical Cytometry Society.

Specimen Referral Network to Rapidly Scale-Up CD4 Testing: The Hub and Spoke Model for Haiti

OBJECTIVES

Regular and quality CD4 testing is essential to monitor disease progression in people living with HIV. In Haiti, most laboratories have limited infrastructure and financial resources and have relied on manual laboratory techniques. We report the successful implementation of a national specimen referral network to rapidly increase patient coverage with quality CD4 testing while at the same time building infrastructure for referral of additional sample types over time.

METHOD

Following a thorough baseline analysis of facilities, expected workload, patient volumes, cost of technology and infrastructure constraints at health institutions providing care to HIV patients, the Haitian National Public Health Laboratory designed and implemented a national specimen referral network. The specimen referral network was scaled up in a step-wise manner from July 2011 to July 2014.

RESULTS

Fourteen hubs serving a total of 67 healthcare facilities have been launched; in addition, 10 healthcare facilities operate FACSCount machines, 21 laboratories operate PIMA machines, and 11 healthcare facilities are still using manual CD4 tests. The number of health institutions able to access automated CD4 testing has increased from 27 to 113 (315%). Testing volume increased 76% on average. The number of patients enrolled on ART at the first healthcare facilities to join the network increased 182% within 6 months following linkage to the network. Performance on external quality assessment was acceptable at all 14 hubs.

CONCLUSION

A specimen referral network has enabled rapid uptake of quality CD4 testing, and served as a backbone to allow for other future tests to be scaled-up in a similar way.

Simple and rapid CD4 testing based on large-field imaging system composed of microcavity array and two-dimensional photosensor

This study presents a novel method for CD4 testing based on one-shot large-field imaging. The large-field imaging system was fabricated by a microcavity array and a two-dimensional (2D) photosensor within the desk-top-sized instrument. The microcavity array was employed to separate leukocytes from whole blood based on differences in the size of leukocytes and other blood cells. The large-field imaging system with lower side irradiation enabled acquisition of cell signatures with high signal-to-noise ratio, because the metallic substrate of the microcavity array obstructed excessive excitation light. In this setting, dual-color imaging of CD4(+) and CD8(+) T cells was achieved within the entire image area (64 mm(2)) in 2s. The practical performance of the large-field imaging system was demonstrated by determining the CD4/CD8 ratio in a few microliter of control whole blood as small as those obtained by a finger prick. The CD4/CD8 ratios measured using the large-field imaging system correlated well with those measured by microscopic analysis. These results indicate that our proposed system provides a simple and rapid CD4 testing for the application of HIV/AIDS treatment.