Implementation and Operational Research: Evaluation of a Public-Sector, Provider-Initiated Cryptococcal Antigen Screening and Treatment Program, Western Cape, South Africa

Economic impact of extending reflexed cryptococcal antigenaemia CD4 threshold in South Africa

Background

Reflexed cryptococcal antigenaemia (CrAg) testing has been offered since 2016 in South Africa, on remnant CD4 specimens, for people with a count < 100 cells/μL. Local guidelines recommended extending testing to 200 cells/μL.

Objectives

This study assessed the cost per result and annual equivalent costs (AEC) for CD4 counts < 100 cells/μL and 100 to 200 cells/μL, as well as determining the cost to find one CrAg-positive case.

Method

An ingredients-based costing was used to determine the cost per result. The CrAg detection rate for < 100 cells/μL was obtained from operational reports of 2019. For 100 cells/μL to 200 cells/μL, a CrAg detection rate of 2% was assumed. One-way sensitivity analysis determined the impact of varying CrAg detection rates on the cost to find one case. Local data from the Western Cape province, which offers testing for counts of 100 cells/μL to 200 cells/μL, from September 2022 to January 2023, were interrogated to establish detection rates.

Results

There were 283 240 (AEC: $1 670 370) specimens with counts of < 100 cells/μL and 300 624 (AEC: $1 772 890) with counts of 100 cells/μL to 200 cells/μL. A cost per result of $5.897 was reported. The cost to find one CrAg case ranged from $589.74 to $73.72 for a detection rate of 1% to 8%. Local data for a count of 100 cells/μL to 200 cells/μL revealed a CrAg detection rate of 1.6%.

Conclusion

The study findings reveal that extending reflexed CrAg testing to 200 cells/μL would double test volumes with fewer positive cases reported for those with a count of 100 cells/μL to 200 cells/μL.

Cryptococcal Antigenemia in Advanced Human Immunodeficiency Virus Disease: Pathophysiology, Epidemiology, and Clinical Implications

Cryptococcal antigen (CrAg) is detectable in blood prior to the onset of symptomatic cryptococcal meningitis (CM), a leading cause of death among people with advanced human immunodeficiency virus (HIV) disease globally. Highly sensitive assays can detect CrAg in blood, and screening people with HIV with low CD4 counts, followed by preemptive antifungal treatment, is recommended and widely implemented as part of a global strategy to prevent CM and end cryptococcal-related deaths. Cryptococcal antigenemia encompasses a spectrum of conditions from preclinical asymptomatic infection (cerebrospinal fluid [CSF] CrAg-negative) through subclinical (CSF CrAg-positive without overt meningism) to clinical symptomatic cryptococcal disease, usually manifesting as CM. In this review, we summarize current understanding of the pathophysiology, risk factors for, and clinical implications of cryptococcal antigenemia within this spectrum. We also provide an update on global prevalence, recommended screening and treatment strategies, and future considerations for improving outcomes among patients with cryptococcal antigenemia.

Cost-Effectiveness Analysis of the Implementation of Cryptococcal Antigen Lateral Flow Assay for the Diagnosis of Cryptococcal Meningitis in Symptomatic People Living With Human Immunodeficiency Virus in Brazil

OBJECTIVES

Cryptococcal meningitis constitutes a significant source of mortality in the developing world. Annually, approximately 625 000 deaths occur worldwide among patients with human immunodeficiency virus (HIV) infection. This study aims to assess the cost-effectiveness of implementing cryptococcal antigen lateral flow assay (CRAG-LFA) screening in Brazil compared with the current practice.

METHODS

An economic evaluation using a Monte Carlo microsimulation was conducted, considering the perspective of the Brazilian Public Health System, to calculate the cost-effectiveness of 4 diagnosis tests: (1) CRAG-LFA, (2) the cryptococcal antigen latex agglutination (CRAG-LA) test, (3) India ink, and (4) nontracking as a baseline. The time horizon comprised 1 year for the intervention and 5 years for the budgetary impact analysis. Two primary effectiveness outcomes were considered: years of life and quality-adjusted life-years.

RESULTS

CRAG-LFA has extended dominance vis à vis CRAG-LA and India ink. CRAG-LFA would cost $418.46 more than CRAG-LA for the treatment of each symptomatic patient living with HIV, with an incremental cost effectiveness ratio of $2478.75/quality-adjusted life year. The budgetary impact analysis estimated that the incorporation of CRAG-LFA would have an additional cost of $1 959 236.50 in 5 years.

CONCLUSIONS

These findings suggest that, for patients living with HIV in the Brazilian Public Health System, the adoption of CRAG-LFA screening is cost-effective compared with the use of CRAG-LA and India ink. It represents an opportunity to prevent cryptococcal meningitis and its mortality in Brazil.

Establishing targets for advanced HIV disease: A call to action

The World Health Organization (WHO) has published a guideline for the management of individuals with advanced HIV disease (AHD) to reduce HIV-related deaths. The guideline consists of a package of recommendations including interventions to prevent, diagnose and treat common opportunistic infections, including tuberculosis (TB), cryptococcosis and severe bacterial infections, along with rapid initiation of antiretroviral treatment and enhanced adherence support. Currently no clear targets exist for these key interventions. Emerging programmatic data from Uganda, Tanzania and Nigeria suggest that an estimated 80% of eligible people continue to miss the recommended cryptococcal or TB testing, highlighting the remaining challenges to the effective implementation of WHO-recommended AHD packages of care in real-world resource-limited settings. The absence of mortality indicators for the leading causes of HIV-related deaths, because of the lack of mechanisms to ascertain cause of death, has had a negative impact on establishing interventions to reduce mortality. We suggest that setting 95-95-95 targets for CD4 testing, cryptococcal antigen and TB testing, and treatment that are aligned to the WHO AHD package of care would be a step in the right direction to achieving the greater goal of the WHO End TB strategy and the proposed new strategy to end cryptococcal meningitis deaths. However, these targets will only be achieved if there is healthcare worker training, expanded access to bedside point-of-care diagnostics for hospitalised patients and those in outpatient care who meet the criteria for AHD, and health systems strengthening to minimise delays in initiating the WHO-recommended therapies for TB and cryptococcal disease.

Prevalence and Sequelae of Cryptococcal Antigenemia in Antiretroviral Therapy-Experienced Populations: An Evaluation of Reflex Cryptococcal Antigen Screening in Botswana

BACKGROUND

Evidence to inform cryptococcal antigen (CrAg)-screening guidelines among ART-experienced populations is lacking. We performed a study evaluating the utility of reflex CrAg screening in Gaborone, Botswana.

METHODS

CD4 count data were collected from the HIV reference laboratory from 2014-2016. CrAg screening was performed on samples with CD4 ≤100 cells/µL beginning January 2015. The proportion of CD4 counts ≤100 cells/µL was determined and the frequency of repeat CrAg testing described. Analyses ascertained the impact of ART status on CrAg prevalence and outcomes, and whether CrAg titers could be used for risk stratification.

RESULTS

Overall, 5.6% (3335/59 300) of individuals tested had CD4 ≤100 cells/μL; 2108 samples with CD4 ≤100 cells/μL from 1645 unique patients were CrAg tested. Over half of samples were from ART-experienced individuals: 40.9% (863) on ART and 12.1% (255) defaulters; 22% (463) of CrAg tests were on repeat samples. CrAg prevalence was 4.8% (72/1494; 95% CI, 3.8-6.0%) among outpatients and 21.9% (32/151; 95% CI, 15.3-28.5%) among inpatients. CrAg prevalence rates did not differ by ART status, but 6-month mortality was significantly lower in CrAg-positive individuals on ART at screening. Ten CrAg positives were identified through repeat testing. A CrAg titer cutoff ≥1:80 provided the best discrimination for 6-month survival.

CONCLUSIONS

CrAg-positivity rates in an ART-experienced population were comparable to those seen in ART-naive populations. Repeat screening identified individuals who seroconverted to CrAg positivity and were at risk of cryptococcal disease. CrAg titers ≥1:80 can help identify the individuals at highest risk of death for more intensive management.

Continuous quality improvement in HIV and TB services at selected healthcare facilities in South Africa

Background

Continuous quality improvement (CQI) is essential for HIV and tuberculosis (TB) services. Similarly, a thorough understanding of the requirements and impact of CQI is critical to its successful institutionalisation. However, this is currently lacking.

Objectives

The objective of this study is to describe the CQI implementation process and examine its effect on HIV and TB service delivery at selected primary healthcare facilities in two South African districts.

Method

We used a separate sample, pre- and post-test, quasi-experimental study design based on data collected from the clinical audit of patient cohorts seen in 2014 and 2015 respectively. Quality was measured based on the extent to which prescribed services were provided. Tailored CQI interventions were implemented based on service delivery gaps identified by the 2014 CQI audit. Data were summarised and analysed using a combination of univariate and multivariate analysis.

Results

The services identified as low quality were related to opportunistic infections management and laboratory practices. Compliance to prescribed service items in antiretroviral treatment initiation and monitoring, pharmacy and laboratory management, exceeded 70% across study sites. Over 80% of low quality service delivery items were optimised in less than six months with targeted quality improvement support.

Conclusion

The observed improvements signal the effectiveness of the CQI approach, its capacity to rapidly improve under-performance, its high replicability and the need to provide quality maintenance support to sustain or improve healthcare facilities performing well. The study strongly underscores the need to improve the management of opportunistic infections and complications, particularly TB.

Asymptomatic cryptococcal antigenemia in HIV-infected patients: a review of recent studies

The prevalence of asymptomatic cryptococcal antigenemia (ACA) in human immunodeficiency virus (HIV) infected individuals has been observed to be elevated. The prevalence of ACA ranges from 1.3% to 13%, with different rates of prevalence in various regions of the world. We reviewed studies conducted internationally, and also referred to two established expert consensus guideline documents published in China, and we have concluded that Chinese HIV-infected patients should undergo cryptococcal antigen screening when CD4 T-cell counts fall below 200 cells/μL and that the recommended treatment regimen for these patients follow current World Health Organization guidelines, although it is likely that this recommendation may change in the future. Early screening and optimized preemptive treatment for ACA is likely to help decrease the incidence of cryptococcosis, and is lifesaving. Further studies are warranted to explore issues related to the optimal management of ACA.

Cryptococcal Antigenemia in Human Immunodeficiency Virus Antiretroviral Therapy-Experienced Ugandans With Virologic Failure

BACKGROUND

Detectable serum or plasma cryptococcal antigen (CrAg) precedes symptomatic cryptococcal meningitis. The World Health Organization recommends CrAg screening for human immunodeficiency virus-positive persons with CD4 count <100 cells/μL initiating antiretroviral therapy (ART). However, an increasing proportion of patients with cryptococcosis are now ART experienced. Whether CrAg screening is cost-effective in those with virologic failure is unknown.

METHODS

We retrospectively performed nationwide plasma CrAg testing among ART-experienced Ugandan adults with virologic failure (≥1000 copies/mL) using leftover plasma after viral load testing during September 2017-January 2018. For those who were CrAg positive, we obtained ART history, meningitis occurrence, and 6-month survival via medical records review.

RESULTS

Among 1186 subjects with virologic failure, 35 (3.0%) were CrAg positive with median ART duration of 41 months (interquartile range, 10-84 months). Among 25 subjects with 6-month outcomes, 16 (64%) survived, 7 (28%) died, and 2 (8%) were lost. One survivor had suffered cryptococcal meningitis 2 years prior. Two others developed cryptococcal meningitis and survived. Five survivors were known to have received fluconazole. Thus, meningitis-free survival at 6 months was 61% (14/23). Overall, 91% (32/35) of CrAg-positive persons had viral load ≥5000 copies/mL compared with 64% (735/1151) of CrAg-negative persons (odds ratio, 6.0 [95% confidence interval, 1.8-19.8]; P = .001). CrAg prevalence was 4.2% (32/768) among those with viral loads ≥5000 copies/mL and 0.7% (3/419) among those with viral loads <5000 copies/mL.

CONCLUSIONS

In addition to the CD4 threshold of <100 cells/μL, reflexive CrAg screening should be considered in persons failing ART in Uganda with viral loads ≥5000 copies/mL.

Cryptococcal meningitis: a review of cryptococcal antigen screening programs in Africa

INTRODUCTION

Cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Cryptococcal antigen (CrAg) can be detected in the blood prior to development of meningitis. Development of highly sensitive and specific rapid diagnostic CrAg tests has helped facilitate the adoption of CrAg screening programs in 19 African countries.

AREAS COVERED

The biological rationale for CrAg screening and the programmatic strategies for its implementation are reviewed. We describe the approach to the investigation of patients with cryptococcal antigenemia and the importance of lumbar puncture to identify individuals who may have cryptococcal meningitis in the absence of symptoms. The limitations of current treatment recommendations and the potential role of newly defined combination antifungal therapies are discussed. A literature review was conducted using a broad database search for cryptococcal antigen screening and related terms in published journal articles dating up to December 2019. Conference abstracts, publicly available guidelines, and project descriptions were also incorporated.

EXPERT OPINION

As we learn more about the risks of cryptococcal antigenemia, it has become clear that the current management paradigm is inadequate. More intensive investigation and management are required to prevent the development of cryptococcal meningitis and reduce mortality associated with cryptococcal antigenemia.

Framework for the implementation of advanced HIV disease diagnostics in sub-Saharan Africa: programmatic perspectives

Patients with advanced HIV disease have a high risk of mortality, mainly from tuberculosis and cryptococcal meningitis. The advanced HIV disease management package recommended by WHO, which includes diagnostics, therapeutics, and patient psychosocial support, is barely implemented in many different countries. Here, we present a framework for the implementation of advanced HIV disease diagnostics. Laboratory and point-of-care-based reflex testing, coupled with provider-initiated requested testing, for cryptococcal antigen and urinary Mycobacterium tuberculosis lipoarabinomannan antigen, should be done for all patients with CD4⁺ cell counts of 200 cells per μL or less. Implementation of the advanced HIV disease package should be encouraged within primary health-care facilities and task shifting of testing to lay cadres could facilitate access to rapid results. Implementation of differentiated antiretroviral therapy delivery models can allow clinicians enough time to focus on the management of patients with advanced HIV disease. Efficient up-referral and post-discharge systems, including the development of patient-centric advanced HIV disease literacy, are also crucial. Implementation of the advanced HIV disease package is feasible at all health-care levels, and it should be part of the core of the global response towards ending AIDS as a public health threat.

Impact of Routine Cryptococcal Antigen Screening and Targeted Preemptive Fluconazole Therapy in Antiretroviral-naive Human Immunodeficiency Virus-infected Adults With CD4 Cell Counts <100/μL: A Systematic Review and Meta-analysis

Cryptococcal antigen (CrAg) screening and targeted preemptive fluconazole in antiretroviral-naive human immunodeficiency virus-infected adults with CD4 cell counts <100/μL seems promising as a strategy to reduce the burden of cryptococcal meningitis (CM). We searched MEDLINE, EMBASE, and Web of Science and used random-effect meta-analysis to assess the prevalence of blood CrAg positivity (31 studies; 35644 participants) and asymptomatic CM in CrAg-positive participants and the incidence of CM and the all-cause mortality rate in screened participants. The pooled prevalence of blood CrAg-positivity was 6% (95% confidence interval [CI], 5%-7%), and the prevalence of asymptomatic CM in CrAg-positive participants was 33% (95% CI, 21%-45%). The incidence of CM was 21.4% (95% CI, 11.6%-34.4%) without preemptive fluconazole and 5.7% (95% CI, 3.0%-9.7%) with preemptive fluconazole therapy initiated at 800 mg/d. In CrAg-positive participants, postscreening lumbar puncture before initiating preemptive fluconazole at 800 mg/d further reduced the incidence of CM to null and showed some survival benefits. However, the all-cause mortality rate remained significantly higher in CrAg-positive than in CrAg-negative participants (risk ratio, 2.2; 95% CI, 1.7-2.9; P < .001).

Emerging concepts in HIV-associated cryptococcal meningitis

PURPOSE OF REVIEW

HIV-associated cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Even in clinical trial settings 10-week mortality is roughly 40%. A number of important clinical trials have either recently concluded or are actively recruiting.

RECENT FINDINGS

Global burden of disease estimates suggest cryptococcal meningitis causes 181 100 deaths annually. Screening blood for cryptococcal antigen in HIV-infected individuals with CD4 cell counts less than 100 cells/μl and preemptive antifungal treatment for those with detectable cryptococcal antigen reduces the incidence of cryptococcal meningitis and is likely to reduce mortality. Cryptococcal meningitis treatment with conventional 14-day courses of amphotericin are associated with high toxicity and mortality and can be reduced to 7 days if given alongside flucytosine. Flucytosine is a significantly superior adjunct to amphotericin treatment compared with fluconazole. In settings without amphotericin B dual oral antifungal combinations of flucytosine and fluconazole offer an effective alternative treatment. A single, high-dose of liposomal amphotericin is effective at reducing fungal burden and is being tested in a phase III trial.

SUMMARY

Recently completed and ongoing clinical trials are increasing our understanding of how to optimize induction therapy for cryptococcal meningitis. Advocacy efforts are needed to broaden access to amphotericin formulations and flucytosine.

Pathways to care and outcomes among hospitalised HIV-seropositive persons with cryptococcal meningitis in South Africa

Introduction

Cryptococcus causes 15% of AIDS-related deaths and in South Africa, with its high HIV burden, is the dominant cause of adult meningitis. Cryptococcal meningitis (CM) mortality is high, partly because patients enter care with advanced HIV disease and because of failure of integrated care following CM diagnosis. We evaluated pathways to hospital care, missed opportunities for HIV testing and initiation of care.

Methods

We performed a cross-sectional study at five public-sector urban hospitals. We enrolled adults admitted with a first or recurrent episode of cryptococcal meningitis. Study nurses conducted interviews, supplemented by a prospective review of medical charts and laboratory records.

Results

From May to October 2015, 102 participants were enrolled; median age was 40 years (interquartile range [IQR] 33.9–46.7) and 56 (55%) were male. In the six weeks prior to admission, 2/102 participants were asymptomatic, 72/100 participants sought care at a public-sector facility, 16/100 paid for private health care. The median time from seeking care to admission was 4 days (IQR, 0–27 days). Of 94 HIV-seropositive participants, only 62 (66%) knew their status and 41/62 (66%) had ever taken antiretroviral treatment. Among 13 participants with a known previous CM episode, none were taking fluconazole maintenance therapy. In-hospital management was mostly amphotericin B; in-hospital mortality was high (28/92, 30%). Sixty-four participants were discharged, 92% (59/64) on maintenance fluconazole, 4% (3/64) not on fluconazole and 3% (2/64) unknown. Twelve weeks post-discharge, 31/64 (48%) participants were lost to follow up. By 12 weeks post discharge 7/33 (21%) had died. Interviewed patients were asked if they were still on fluconazole, 11% (2/18) were not.

Conclusions

Among hospitalised participants with CM, there were many missed opportunities for HIV care and linkage to ART prior to admission. Universal reflex CrAg screening may prompt earlier diagnosis of cryptococcal meningitis but there is a wider problem of timely linkage to care for HIV-seropositive people.

Reflexive Laboratory-Based Cryptococcal Antigen Screening and Preemptive Fluconazole Therapy for Cryptococcal Antigenemia in HIV-Infected Individuals With CD4 <100 Cells/µL: A Stepped-Wedge, Cluster-Randomized Trial

Supplemental Digital Content is Available in the Text.

Background:

HIV-infected persons with cryptococcal antigenemia (CrAg) are at high risk for meningitis or death. We evaluated the effect of CrAg screening and preemptive fluconazole therapy, adjunctive to antiretroviral therapy (ART), on 6-month survival among persons with advanced HIV/AIDS.

Methods:

We enrolled HIV-infected, ART-naive participants with <100 CD4 cells/µL, in a stepped-wedge, cluster-randomized trial from July 2012 to December 2014 at 17 Ugandan clinics. Clinics participated in a prospective observational phase, followed by an interventional phase with laboratory-based, reflexive CrAg screening of residual CD4 count plasma. Asymptomatic CrAg+ participants received preemptive fluconazole therapy. We assessed 6-month survival using Cox-regression, adjusting for nadir CD4, calendar time, and stepped-wedge steps.

Results:

We included 1280 observational and 2108 interventional participants, of whom 9.3% (195/2108) were CrAg+. CD4-, time-, and stepped-wedge–adjusted analyses demonstrated no difference in survival in the observational vs the interventional arms (hazard ratio = 1.34; 95% confidence interval: 0.86 to 2.10; P = 0.20). Fewer participants initiated ART in the interventional (73%) versus the observational phase (82%, P < 0.001). When ART initiation was modeled as a time-dependent covariate or confounder, survival did not differ. However, 6-month mortality of participants with CrAg titers <1:160 and CrAg-negative patients did not differ. Patients with CrAg titers ≥1:160 had 2.6-fold higher 6-month mortality than patients with titers <1:160.

Conclusions:

We observed no overall survival benefit of the CrAg screen-and-treat intervention. However, preemptive antifungal therapy for asymptomatic cryptococcosis seemed to be effective in patients with CrAg titer <1:160. A more aggressive approach is required for persons with CrAg titer ≥1:160.

Laboratory-Reflex Cryptococcal Antigen Screening Is Associated With a Survival Benefit in Tanzania

BACKGROUND

Cryptococcal antigen (CrAg) screening in persons with advanced HIV/AIDS is recommended to prevent death. Implementing CrAg screening only in outpatients may underestimate the true CrAg prevalence and decrease its potential impact. Our previous 12-month survival/retention in CrAg-positive persons not treated with fluconazole was 0%.

METHODS

HIV testing was offered to all antiretroviral therapy-naive outpatients and hospitalized patients in Ifakara, Tanzania, followed by laboratory-reflex CrAg screening for CD4 <150 cells/μL. CrAg-positive individuals were offered lumbar punctures, and antifungals were tailored to the presence/absence of meningitis. We assessed the impact on survival and retention-in-care using multivariate Cox-regression models.

RESULTS

We screened 560 individuals for CrAg. The median CD4 count was 61 cells/μL (interquartile range 26-103). CrAg prevalence was 6.1% (34/560) among individuals with CD4 ≤150 and 7.5% among ≤100 cells/μL. CrAg prevalence was 2.3-fold higher among hospitalized participants than in outpatients (12% vs 5.3%, P = 0.02). We performed lumbar punctures in 94% (32/34), and 31% (10/34) had cryptococcal meningitis. Mortality did not differ significantly between treated CrAg-positive without meningitis and CrAg-negative individuals (7.3 vs 5.4 deaths per 100 person-years, respectively, P = 0.25). Independent predictors of 6-month death/lost to follow-up were low CD4, cryptococcal meningitis (adjusted hazard ratio 2.76, 95% confidence interval: 1.31 to 5.82), and no antiretroviral therapy initiation (adjusted hazard ratio 3.12, 95% confidence interval: 2.16 to 4.50).

CONCLUSIONS

Implementing laboratory-reflex CrAg screening among outpatients and hospitalized individuals resulted in a rapid detection of cryptococcosis and a survival benefit. These results provide a model of a feasible, effective, and scalable CrAg screening and treatment strategy integrated into routine care in sub-Saharan Africa.

A Prospective Evaluation of a Multisite Cryptococcal Screening and Treatment Program in HIV Clinics in Uganda

BACKGROUND

Cryptococcus is a leading cause of AIDS-related mortality. Cryptococcal antigen (CrAg) is detectable in blood before meningitis onset and predicts death. CrAg screening among those with advanced HIV, and treatment of those CrAg+ with fluconazole, has demonstrated survival benefit. However, implementation and widespread uptake have been slow outside clinical trials.

METHODS

We designed a CrAg screening program for routine care that incorporated intensive education and training of clinic staff. We evaluated programmatic implementation, including time to initiation of fluconazole, time to initiation of antiretroviral therapy, and 6-month clinical outcomes.

RESULTS

Between December 2015 and January 2017, 1440 persons were screened at 11 HIV clinics in Kampala, and CRAG+ prevalence was 6.5% (n = 94/1440) among adults with a CD4 <100 cells/µL. Of those CrAg+, 7 of 94 persons (7%) died or were lost before further clinic evaluation. Fifty-three persons (56%) were asymptomatic and had 6-month survival of 87% (46/53). Of CrAg+ persons, 28% (26/94) were symptomatic at the time of clinic return. Most had confirmed cryptococcal meningitis, and 54% (14/26) of the symptomatic CrAg+ persons were dead or lost at 6 months. Of the 7 symptomatic persons who declined lumbar puncture for further evaluation, all were dead or lost by 6 months.

CONCLUSION

All asymptomatic CrAg+ persons identified by our screening program who returned to clinic, initated fluconazole and antiretroviral therapy in a timely manner. Despite this, 27% of CrAg+ (asymptomatic and symptomatic) identified on routine screening were dead or lost to follow-up at 6 months, even with preemptive therapy for those asymptomatic, and standard amphotericin-based treatment for meningitis.

The Continuing Value of CD4 Cell Count Monitoring for Differential HIV Care and Surveillance

The move toward universal provision of antiretroviral therapy and the expansion of HIV viral load monitoring call into question the ongoing value of CD4 cell count testing and monitoring. We highlight the role CD4 monitoring continues to have in guiding clinical decisions and measuring and evaluating the epidemiology of HIV. To end the HIV/AIDS epidemic, we require strategic information, which includes CD4 cell counts, to make informed clinical decisions and effectively monitor key surveillance indicators.

Cryptococcal Meningitis Diagnostics and Screening in the Era of Point-of-Care Laboratory Testing

Over the past ten years, standard diagnostics for cryptococcal meningitis in HIV-infected persons have evolved from culture to India ink to detection of cryptococcal antigen (CrAg), with the recent development and distribution of a point-of-care lateral flow assay. This assay is highly sensitive and specific in cerebrospinal fluid (CSF), but is also sensitive in the blood to detect CrAg prior to meningitis symptoms. CrAg screening of HIV-infected persons in the blood prior to development of fulminant meningitis and preemptive treatment for CrAg-positive persons are recommended by the World Health Organization and many national HIV guidelines. Thus, CrAg testing is occurring more widely, especially in resource-limited laboratory settings. CrAg titer predicts meningitis and death and could be used in the future to customize therapy according to burden of infection.

A qualitative evaluation of an implementation study for cryptococcal antigen screening and treatment in Uganda

Cryptococcal meningiti s causes 15% of AIDS-related deaths globally. Screening and preemptive treatment for cryptococcal antigen (CrAg) in the blood of persons with advanced HIV/AIDS reduces mortality. National and international HIV guidelines recommend CrAg screening; however, implementation studies and evaluations of how to integrate CrAg screening programs into existing HIV care infrastructure are lacking.During a CrAg screening program in Kampala, Uganda, we interviewed 15 health care workers (2 coordinating research nurses and 13 clinic personnel) from 6 HIV clinics between March and April 2017, to identify barriers to implementation as well as facilitating factors for program success. The interviews were coded and themes compiled.We found key factors for successful implementation of a CrAg screening program were: adequate supplies of fluconazole and CrAg lateral flow assay (LFA) point-of-care tests, timely patient follow-up, and quick turnaround time of laboratory results. Although both CrAg LFA kits and fluconazole are on the national formulary, stockouts are common, affecting patient care. The CrAg screening recommendation by national HIV guidelines remains integral to the success of the program, as overburdened clinics are otherwise reluctant to adopt additional screening. Collaboration with Ministries of Health for support with enforcing national guidelines, and procuring supplies is paramount to a successful CrAg screening program.Development of a CrAg screening and treatment program within the HIV clinic infrastructure has a number of barriers. Education and training of clinic staff, along with partnership with the Ministry of Health to ensure adequate supplies, facilitated the program.

The Continuing Burden of Advanced HIV Disease Over 10 Years of Increasing Antiretroviral Therapy Coverage in South Africa

Background

Antiretroviral treatment (ART) has been massively scaled up to decrease human immunodeficiency virus (HIV)-related morbidity, mortality, and HIV transmission. However, despite documented increases in ART coverage, morbidity and mortality have remained substantial. This study describes trends in the numbers and characteristics of patients with very advanced HIV disease in the Western Cape, South Africa.

Methods

Annual cross-sectional snapshots of CD4 distributions were described over 10 years, derived from a province-wide cohort of all HIV patients receiving CD4 cell count testing in the public sector. Patients with a first CD4 count <50 cells/µL in each year were characterized with respect to prior CD4 and viral load testing, ART access, and retention in ART care.

Results

Patients attending HIV care for the first time initially constituted the largest group of those with CD4 count <50 cells/µL, dropping proportionally over the decade from 60.9% to 26.7%. By contrast, the proportion who were ART experienced increased from 14.3% to 56.7%. In patients with CD4 counts <50 cells/µL in 2016, 51.8% were ART experienced, of whom 76% could be confirmed to be off ART or had recent viremia. More than half who were ART experienced with a CD4 count <50 cells/µL in 2016 were men, compared to approximately one-third of all patients on ART in the same year.

Conclusions

Ongoing HIV-associated morbidity now results largely from treatment-experienced patients not being in continuous care or not being fully virologically suppressed. Innovative interventions to retain ART patients in effective care are an essential priority for the ongoing HIV response.

CD4 Cell Count Threshold for Cryptococcal Antigen Screening of HIV-Infected Individuals: A Systematic Review and Meta-analysis

Background

Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts.

Methods

We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models.

Results

Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval [CI], 5.7%-7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%-2.7%; 21 studies) among patients with CD4 count 101-200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%-22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101-200 cells/µL. CrAg prevalence was higher among inpatients (9.8% [95% CI, 4.0%-15.5%]) compared with outpatients (6.3% [95% CI, 5.3%-7.4%]).

Conclusions

The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL.

Estimating the cost-per-result of a national reflexed Cryptococcal antigenaemia screening program: Forecasting the impact of potential HIV guideline changes and treatment goals

Introduction

During 2016, the National Health Laboratory Service (NHLS) introduced laboratory-based reflexed Cryptococcal antigen (CrAg) screening to detect early Cryptococcal disease in immunosuppressed HIV+ patients with a confirmed CD4 count of 100 cells/μl or less.

Objective

The aim of this study was to assess cost-per-result of a national screening program across different tiers of laboratory service, with variable daily CrAg test volumes. The impact of potential ART treatment guideline and treatment target changes on CrAg volumes, platform choice and laboratory workflow are considered.

Methods

CD4 data (with counts < = 100 cells/μl) from the fiscal year 2015/16 were extracted from the NHLS Corporate Date Warehouse and used to project anticipated daily CrAg testing volumes with appropriately-matched CrAg testing platforms allocated at each of 52 NHLS CD4 laboratories. A cost-per-result was calculated for four scenarios, including the existing service status quo (Scenario-I), and three other settings (as Scenarios II-IV) which were based on information from recent antiretroviral (ART) guidelines, District Health Information System (DHIS) data and UNAIDS 90/90/90 HIV/AIDS treatment targets. Scenario-II forecast CD4 testing offered only to new ART initiates recorded at DHIS. Scenario-III projected all patients notified as HIV+, but not yet on ART (recorded at DHIS) and Scenario-IV forecast CrAg screening in 90% of estimated HIV+ patients across South Africa (also DHIS). Stata was used to assess daily CrAg volumes at the 5^th, 10^th, 25^th, 50^th, 75^th, 90^th and 95^th percentiles across 52 CD4-laboratories. Daily volumes were used to determine technical effort/ operator staff costs (% full time equivalent) and cost-per-result for all scenarios.

Results

Daily volumes ranged between 3 and 64 samples for Scenario-I at the 5th and 95th percentile. Similarly, daily volumes ranges of 1–12, 2–45 and 5–100 CrAg-directed samples were noted for Scenario’s II, III and IV respectively. A cut-off of 30 CrAg tests per day defined use of either LFA or EIA platform. LFA cost-per-result ranged from $8.24 to $5.44 and EIA cost-per-result between $5.58 and $4.88 across the range of test volumes. The technical effort across scenarios ranged from 3.2–27.6% depending on test volumes and platform used.

Conclusion

The study reported the impact of programmatic testing requirements on varying CrAg test volumes that subsequently influenced choice of testing platform, laboratory workflow and cost-per-result. A novel percentiles approach is described that enables an overview of the cost-per-result across a national program. This approach facilitates cross-subsidisation of more expensive lower volume sites with cost-efficient, more centralized higher volume laboratories, mitigating against the risk of costing tests at a single site.

Looking for fungi in all the right places: screening for cryptococcal disease and other AIDS-related mycoses among patients with advanced HIV disease

PURPOSE OF REVIEW

As HIV treatment programmes scale up to meet the UNAIDS 90-90-90 goals, care must be taken to start antiretroviral treatment safely in patients with advanced disease (CD4 counts <200 cells/μl) who are simultaneously at risk for opportunistic infections and immune reconstitution inflammatory syndrome. Invasive fungal diseases pose a great threat at this critical time point, though the development of inexpensive and highly accurate rapid diagnostic tests has changed the approach HIV programmes are taking to reduce the high mortality associated with these opportunistic infections. This article summarizes recent advances and findings in fungal opportunistic infection diagnostics with a focus on screening to prevent cryptococcal meningitis.

RECENT FINDINGS

Cryptococcal antigen (CrAg) screening using a lateral flow assay platform is cost-effective and feasible to implement as either a laboratory reflex or point-of-care test. Recent CrAg screening pilots have elucidated the varying prevalence of cryptococcal antigenemia across geographic regions, which may aid programme planning. Evidence from recently completed clinical trials provides a strong motivation for the use of CrAg titer to refine treatment options for patients with subclinical cryptococcal disease.

SUMMARY

Although several operational barriers to programme effectiveness still need to be addressed, the utility of CrAg screening using inexpensive and accurate antigen assays has been demonstrated in real-world HIV programmes, paving the way for development and testing of other fungal opportunistic infection screening strategies and for an integrated advanced HIV disease testing package to reduce AIDS mortality and ensure safe antiretroviral treatment initiation.

Improvement of fungal disease identification and management: combined health systems and public health approaches

More than 1·6 million people are estimated to die of fungal diseases each year, and about a billion people have cutaneous fungal infections. Fungal disease diagnosis requires a high level of clinical suspicion and specialised laboratory testing, in addition to culture, histopathology, and imaging expertise. Physicians with varied specialist training might see patients with fungal disease, yet it might remain unrecognised. Antifungal treatment is more complex than treatment for bacterial or most viral infections, and drug interactions are particularly problematic. Health systems linking diagnostic facilities with therapeutic expertise are typically fragmented, with major elements missing in thousands of secondary care and hospital settings globally. In this paper, the last in a Series of eight papers, we describe these limitations and share responses involving a combined health systems and public health framework illustrated through country examples from Mozambique, Kenya, India, and South Africa. We suggest a mainstreaming approach including greater integration of fungal diseases into existing HIV infection, tuberculosis infection, diabetes, chronic respiratory disease, and blindness health programmes; provision of enhanced laboratory capacity to detect fungal diseases with associated surveillance systems; procurement and distribution of low-cost, high-quality antifungal medicines; and concomitant integration of fungal disease into training of the health workforce.

Cost-effectiveness of CRAG-LFA screening for cryptococcal meningitis among people living with HIV in Uganda

Background

Cryptococcal meningitis (CM) constitutes a significant source of mortality in resource-limited regions. Cryptococcal antigen (CRAG) can be detected in the blood before onset of meningitis. We sought to determine the cost-effectiveness of implementing CRAG screening using the recently developed CRAG lateral flow assay in Uganda compared to current practice without screening.

Methods

A decision-analytic model was constructed to compare two strategies for cryptococcal prevention among people living with HIV with CD4 < 100 in Uganda: No cryptococcal screening vs. CRAG screening with WHO-recommended preemptive treatment for CRAG-positive patients. The model was constructed to reflect primary HIV clinics in Uganda, with a cohort of HIV-infected patients with CD4 < 100 cells/uL. Primary outcomes were expected costs, DALYs, and incremental cost-effectiveness ratios (ICERs). We evaluated varying levels of programmatic implementation in secondary analysis.

Results

CRAG screening was considered highly cost-effective and was associated with an ICER of $6.14 per DALY averted compared to no screening (95% uncertainty range: $-20.32 to $36.47). Overall, implementation of CRAG screening was projected to cost $1.52 more per person, and was projected to result in a 40% relative reduction in cryptococcal-associated mortality. In probabilistic sensitivity analysis, CRAG screening was cost-effective in 100% of scenarios and cost saving (ie cheaper and more effective than no screening) in 30% of scenarios. Secondary analysis projected a total cost of $651,454 for 100% implementation of screening nationally, while averting 1228 deaths compared to no screening.

Conclusion

CRAG screening for PLWH with low CD4 represents excellent value for money with the potential to prevent cryptococcal morbidity and mortality in Uganda.