Evaluation of screening and treatment of cryptococcal antigenaemia among HIV-infected persons in Soweto, South Africa

Prevalence of Cryptococcal Antigenemia and Lateral Flow Assay Accuracy in Severely Immunosuppressed AIDS Patients

This study aimed to estimate the prevalence of cryptococcal antigenemia detected by lateral flow assay (LFA) in AIDS patients and its accuracy in the diagnosis of cryptococcosis. Conducted at a university hospital in Brazil from March 2015 to July 2017, it included AIDS patients over 18 years old with a CD4+ count ≤ 200 cells/mm3. Cryptococcal antigen (CrAg) detection using LFA and latex agglutination (LA), along with blood and urine cultures, were performed. The reference standard was the identification of Cryptococcus spp. in clinical specimens through microbiological or histopathological examination. Among 230 patients, the prevalence of CrAg detected by LFA (CrAg LFA) was 13.0%. Factors associated with cryptococcal antigenemia included fever, vomiting, seizures, and a lack of antiretroviral therapy. The sensitivity and specificity of CrAg LFA were 83.9% and 98.0%, respectively. The positive predictive value (PPV) was 86.7%, the negative predictive value (NPV) was 97.5%, and overall accuracy was 96.1%. Cross-reactions were observed in patients with histoplasmosis and paracoccidioidmycosis, but not with aspergillosis or positive rheumatoid factor. The study concludes that the LFA is a useful tool for detecting cryptococcal antigenemia in severely immunocompromised AIDS patients due to its high NPV, specificity, and PPV.

Mapping evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa- A scoping review protocol

INTRODUCTION

Infections of the central nervous system are a considerable basis of mortality in people living with HIV, with progression to cryptococcal meningitis documented at around 15% of HIV-associated mortality globally, with nearly three-quarters occurring in the sub-Saharan Africa. Discoveries from previous studies prelude to the mortality of cryptococcal antigen positive, which persisted to be elevated than in cryptococcal antigen negative persons. One feasible interpretation of this could be due to undiagnosed cryptococcus. Laboratory investigations identify cryptococcal disease prior to cryptococcal meningitis progression. Point-of-care testing has high sensitivity and specificity as seen with the cryptococcal antigen lateral flow assay screening to expedite treatment. The aim of the study is to map and translate evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa.

METHODOLOGY

The proposed scoping review will be conducted using guidelines proposed by Arksey and O'Malley methodological framework and Levac et al. advanced method. It will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews. A comprehensive literature search of studies published from the first relevant publication to 2022 will be conducted on multiple electronic databases. Additional sources (grey literature) will also be searched. The search strategy will be generated and implemented by the principal investigator with assistance from a subject specialist, and an information specialist. Two reviewers will screen eligible studies. The screening will be guided by an inclusion and exclusion criteria. The mixed methods appraisal tool version 2018 will be used to appraise the quality of the empirical studies.

DISCUSSION

The proposed scoping review will map and translate evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa. Synthesising and sharing recent evidence in this area has potential to help guide future research and interventions aimed at improving the management of cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa and other high HIV- burdened settings.

Invasive Fungal Diseases in Africa: A Critical Literature Review

Invasive fungal diseases (IFDs) are of huge concern in resource-limited settings, particularly in Africa, due to the unavailability of diagnostic armamentarium for IFDs, thus making definitive diagnosis challenging. IFDs have non-specific systemic manifestations overlapping with more frequent illnesses, such as tuberculosis, HIV, and HIV-related opportunistic infections and malignancies. Consequently, IFDs are often undiagnosed or misdiagnosed. We critically reviewed the available literature on IFDs in Africa to provide a better understanding of their epidemiology, disease burden to guide future research and interventions. Cryptococcosis is the most encountered IFD in Africa, accounting for most of the HIV-related deaths in sub-Saharan Africa. Invasive aspergillosis, though somewhat underdiagnosed and/or misdiagnosed as tuberculosis, is increasingly being reported with a similar predilection towards people living with HIV. More cases of histoplasmosis are also being reported with recent epidemiological studies, particularly from Western Africa, showing high prevalence rates amongst presumptive tuberculosis patients and patients living with HIV. The burden of pneumocystis pneumonia has reduced significantly probably due to increased uptake of anti-retroviral therapy among people living with HIV both in Africa, and globally. Mucormycosis, talaromycosis, emergomycosis, blastomycosis, and coccidiomycosis have also been reported but with very few studies from the literature. The emergence of resistance to most of the available antifungal drugs in Africa is yet of huge concern as reported in other regions. IFDs in Africa is much more common than it appears and contributes significantly to morbidity and mortality. Huge investment is needed to drive awareness and fungi related research especially in diagnostics and antifungal therapy.

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.

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.

The prevalence of cryptococcal antigen (CrAg) and benefits of pre-emptive antifungal treatment among HIV-infected persons with CD4+ T-cell counts < 200 cells/μL: evidence based on a meta-analysis

Background

Current WHO guidelines (2018) recommend screening for cryptococcal antigen (CrAg) in HIV-infected persons with CD4+ T cell counts< 100 cells/μL, followed by pre-emptive antifungal therapy among CrAg positive (CrAg+) persons, to prevent cryptococcal meningitis related deaths. This strategy may also be considered for those persons with a CD4+ T cell count of < 200 cells/uL according the WHO guidelines. However, there is sparse evidence in the literature supporting CrAg screening and pre-emptive antifungal therapy in those HIV-infected persons with this CD4+ T cell counts< 200 cells/μL.

Method

We conducted a meta-analysis using data extracted from randomized controlled studies (RCTs) and cohort studies found in a search of Pubmed, Web of Science, the Cochrane Library and the EMBASE/MEDLINE database.

Results

The pooled prevalence of CrAg positivity in HIV-infected persons with CD4+ T cell counts< 200 cells/μL was 5% (95%CI: 2–7). The incidence of CM in CrAg+ persons was 3% (95%CI: 1–6). Among those CrAg+ persons who did not receive pre-emptive treatment, or those who received placebo, the incidence of CM was 5% (95%CI: 2–9), whereas the incidence of CM among those who received pre-emptive antifungal therapy was 3% (95%CI: 1–6), which is a statistically significant reduction in incidence of 40% (RR: 7.64, 95%CI: 2.96–19.73, p < 0.00001). As for persons with CD4+ T cell counts between 101 ~ 200 cells/μL, the risk ratio for the incidence of CM among those receiving placebo or no intervention was 1.15, compared to those receiving antifungal treatment (95%CI: 0.16–8.13).

Conclusions

In our meta-analysis the incidence of CM was significantly reduced by pre-emptive antifungal therapy in CrAg+ HIV-infected persons with CD4 <  200 cells/μL. However, more specific observational data in persons with CD4+ T cell counts between 101 ~ 200 cells/μL are required in order to emphasize specific benefit of CrAg screening and pre-emptive antifungal treating in CrAg+ persons with CD4+ T cell counts < 200 cells/μL.

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.

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.

An audit of the screen-and-treat intervention to reduce cryptococcal meningitis in HIV-positive patients with low CD4 count

BACKGROUND

 HIV-associated cryptococcal meningitis (CCM) and related mortality may be prevented by the effective implementation of a screen-and-treat intervention. Aim: The aim of this study was to assess the effectiveness of the screen-and-treat intervention at a regional hospital in KwaZulu-Natal province, South Africa. Method: This was a descriptive study in which the records of patients seen in 2015 and 2016 with a CD4 count ≤ 100 cell/mm3 were retrieved from National Health Laboratory Service (NHLS) records and matched against patients admitted for HIV-associated CCM. Results: A total of 5.1% (190 out of 3702) patients with CD4 count ≤ 100 cell/mm3 were cryptococcal antigen positive (CrAg +ve), of whom 22.6% (43 out of 190) were admitted with CCM. Patients who were CrAg +ve had significantly lower CD4 counts (mean CD4 = 38.9 ± 28.5) when compared to CrAg -ve patients (mean CD4 = 49.9 ± 37.4) with p = 0.0001. Only 2.6% (5 out of 190) of patients were referred for a lumbar puncture (LP) as part of the screen-and-treat intervention, whilst 38 who were CrAg +ve self-presented with CCM. Eighty-eight patients were admitted for suspected CCM: eight because of the screen-and-treat-intervention (none of whom had meningitis based on cerebrospinal fluid results) and 80 of whom self-presented and had confirmed CCM. The overall mortality of patients admitted with CCM was 30% (24 out of 80). Conclusion: The current ad-hoc screen-and-treat intervention was ineffective in detecting patients at risk of developing CCM. Systems need to be put in place to ensure that all CrAg +ve patients have an LP to detect subclinical CCM to improve the outcome for those with HIV-associated CCM.

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.

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.

HIV-Associated Cryptococcal Disease in Resource-Limited Settings: A Case for "Prevention Is Better Than Cure"?

Cryptococcal disease remains a significant source of global morbidity and mortality for people living with HIV, especially in resource-limited settings. The recently updated estimate of cryptococcal disease revealed a global incidence of 223,100 cases annually with 73% of these cases being diagnosed in sub-Saharan Africa. Furthermore, 75% of the estimated 181,100 deaths associated with cryptococcal disease occur in sub-Saharan Africa. Point-of-care diagnostic assays have revolutionised the diagnosis of this deadly opportunistic infection. The theory of asymptomatic cryptococcal antigenaemia as a forerunner to symptomatic meningitis and death has been conclusively proven. Thus, cryptococcal antigenaemia screening coupled with pre-emptive antifungal therapy has been demonstrated as a cost-effective strategy with survival benefits and has been incorporated into HIV national guidelines in several countries. However, this is yet to be implemented in a number of other high HIV burden countries. Flucytosine-based combination therapy during the induction phase is associated with improved survival, faster cerebrospinal fluid sterilisation and fewer relapses. Flucytosine, however, is unavailable in many parts of the world. Studies are ongoing on the efficacy of shorter regimens of amphotericin B. Early diagnosis, proactive antifungal therapy with concurrent management of raised intracranial pressure creates the potential to markedly reduce mortality associated with this disease.

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.

Global burden of disease of HIV-associated cryptococcal meningitis: an updated analysis

BACKGROUND

Cryptococcus is the most common cause of meningitis in adults living with HIV in sub-Saharan Africa. Global burden estimates are crucial to guide prevention strategies and to determine treatment needs, and we aimed to provide an updated estimate of global incidence of HIV-associated cryptococcal disease.

METHODS

We used 2014 Joint UN Programme on HIV and AIDS estimates of adults (aged >15 years) with HIV and antiretroviral therapy (ART) coverage. Estimates of CD4 less than 100 cells per μL, virological failure incidence, and loss to follow-up were from published multinational cohorts in low-income and middle-income countries. We calculated those at risk for cryptococcal infection, specifically those with CD4 less than 100 cells/μL not on ART, and those with CD4 less than 100 cells per μL on ART but lost to follow-up or with virological failure. Cryptococcal antigenaemia prevalence by country was derived from 46 studies globally. Based on cryptococcal antigenaemia prevalence in each country and region, we estimated the annual numbers of people who are developing and dying from cryptococcal meningitis.

FINDINGS

We estimated an average global cryptococcal antigenaemia prevalence of 6·0% (95% CI 5·8-6·2) among people with a CD4 cell count of less than 100 cells per μL, with 278 000 (95% CI 195 500-340 600) people positive for cryptococcal antigen globally and 223 100 (95% CI 150 600-282 400) incident cases of cryptococcal meningitis globally in 2014. Sub-Saharan Africa accounted for 73% of the estimated cryptococcal meningitis cases in 2014 (162 500 cases [95% CI 113 600-193 900]). Annual global deaths from cryptococcal meningitis were estimated at 181 100 (95% CI 119 400-234 300), with 135 900 (75%; [95% CI 93 900-163 900]) deaths in sub-Saharan Africa. Globally, cryptococcal meningitis was responsible for 15% of AIDS-related deaths (95% CI 10-19).

INTERPRETATION

Our analysis highlights the substantial ongoing burden of HIV-associated cryptococcal disease, primarily in sub-Saharan Africa. Cryptococcal meningitis is a metric of HIV treatment programme failure; timely HIV testing and rapid linkage to care remain an urgent priority.

FUNDING

None.

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.

Screening HIV-Infected Patients with Low CD4 Counts for Cryptococcal Antigenemia prior to Initiation of Antiretroviral Therapy: Cost Effectiveness of Alternative Screening Strategies in South Africa

Background

In 2015 South Africa established a national cryptococcal antigenemia (CrAg) screening policy targeted at HIV-infected patients with CD4+ T-lymphocyte (CD4) counts <100 cells/ μl who are not yet on antiretroviral treatment (ART). Two screening strategies are included in national guidelines: reflex screening, where a CrAg test is performed on remnant blood samples from CD4 testing; and provider-initiated screening, where providers order a CrAg test after a patient returns for CD4 test results. The objective of this study was to compare costs and effectiveness of these two screening strategies.

Methods

We developed a decision analytic model to compare reflex and provider-initiated screening in terms of programmatic and health outcomes (number screened, number identified for preemptive treatment, lives saved, and discounted years of life saved) and screening and treatment costs (2015 USD). We estimated a base case with prevalence and other parameters based on data collected during CrAg screening pilot projects integrated into routine HIV care in Gauteng, Free State, and Western Cape Provinces. We conducted sensitivity analyses to explore how results change with underlying parameter assumptions.

Results

In the base case, for each 100,000 CD4 tests, the reflex strategy compared to the provider-initiated strategy has higher screening costs ($37,536 higher) but lower treatment costs ($55,165 lower), so overall costs of screening and treatment are $17,629 less with the reflex strategy. The reflex strategy saves more lives (30 lives, 647 additional years of life saved). Sensitivity analyses suggest that reflex screening dominates provider-initiated screening (lower total costs and more lives saved) or saves additional lives for small additional costs (< $125 per life year) across a wide range of conditions (CrAg prevalence, patient and provider behavior, patient survival without treatment, and effectiveness of preemptive fluconazole treatment).

Conclusions

In countries with substantial numbers of people with untreated, advanced HIV disease such as South Africa, CrAg screening before initiation of ART has the potential to reduce cryptococcal meningitis and save lives. Reflex screening compared to provider-initiated screening saves more lives and is likely to be cost saving or have low additional costs per additional year of life saved.

Prevalence and Hospital Management of Amphotericin B Deoxycholate-Related Toxicities during Treatment of HIV-Associated Cryptococcal Meningitis in South Africa

BACKGROUND

We aimed to establish the prevalence of amphotericin B deoxycholate (AmBd)-related toxicities among South African patients with cryptococcosis and determine adherence to international recommendations to prevent, monitor and manage AmBd-related toxicities.

METHODS

Clinical data were collected from cases of laboratory-confirmed cryptococcosis at 25 hospitals, October 2012 -February 2013. Anemia was defined as hemoglobin (Hb) concentration <10 g/dl, hypokalemia as serum potassium (K) <3.4 mEq/L and nephrotoxicity as an increase in serum creatinine (Cr) to >1.1 times the upper limit of normal. To determine adherence to toxicity prevention recommendations, we documented whether baseline Hb, K and Cr tests were performed, whether pre-emptive hydration and IV potassium chloride (KCl) was administered prior to 80% and 60% of AmBd doses and whether daily oral KCl supplementation was given ≥60% of the time. To determine adherence to monitoring recommendations, we ascertained whether a daily fluid chart was completed, Hb was monitored weekly and K or Cr were monitored bi-weekly.

RESULTS

Of 846 patients, clinical data were available for 76% (642/846), 82% (524/642) of whom received AmBd. Sixty-four per cent (n = 333) had documented baseline laboratory tests, 40% (n = 211) were given pre-emptive hydration and 14% (n = 72) and 19% (n = 101) received intravenous and oral KCl. While on AmBd, 88% (n = 452) had fluid monitoring; 27% (n = 142), 45% (n = 235) and 44% (n = 232) had Hb, K and Cr levels monitored. Toxicities developed frequently during treatment: anemia, 16% (86/524); hypokalemia, 43% (226/524) and nephrotoxicity, 32% (169/524).

CONCLUSION

AmBd-related toxicities occurred frequently but were potentially preventable with adequate monitoring, supplemental fluid and electrolyte therapies.

Preemptive Therapy for Cryptococcal Meningitis: A Valid Strategy for Latin America?

AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. Better diagnostics allow detection of cryptococcosis in the asymptomatic phase and using these technologies to screen at-risk persons would likely reduce mortality. The World Health Organization recommends cryptococcal antigen screening among populations with a prevalence of cryptococcal antigenaemia (CRAG) > 3%. There is scarce data about CRAG prevalence in Latin America. Four studies (only one published as a full text) showed asymptomatic CRAG prevalence between 2.7% and 6.2% in several sub-sets of HIV-infected patients. The CRAG lateral flow assay (LFA) has several advantages over other techniques for actual implementation of a screening program. Although more studies are necessary to confirm available data, implementation of the CRAG screening strategy seems to be opportune in Latin America.

Cryptococcal Antigen Screening in Patients Initiating ART in South Africa: A Prospective Cohort Study

BACKGROUND

Retrospective data suggest that cryptococcal antigen (CrAg) screening in patients with late-stage human immunodeficiency virus (HIV) initiating antiretroviral therapy (ART) may reduce cryptococcal disease and deaths. Prospective data are limited.

METHODS

CrAg was measured using lateral flow assays (LFA) and latex agglutination (LA) tests in 645 HIV-positive, ART-naive patients with CD4 counts ≤100 cells/µL in Cape Town, South Africa. CrAg-positive patients were offered lumbar puncture (LP) and treated with antifungals. Patients were started on ART between 2 and 4 weeks and followed up for 1 year.

RESULTS

A total of 4.3% (28/645) of patients were CrAg positive in serum and plasma with LFA. These included 16 also positive by urine LFA (2.5% of total screened) and 7 by serum LA (1.1% of total). In 4 of 10 LFA-positive cases agreeing to LP, the cerebrospinal fluid (CSF) CrAg LFA was positive. A positive CSF CrAg was associated with higher screening plasma/serum LFA titers.Among the 28 CrAg-positive patients, mortality was 14.3% at 10 weeks and 25% at 12 months. Only 1 CrAg-positive patient, who defaulted from care, died from cryptococcal meningitis (CM). Mortality in CrAg-negative patients was 11.5% at 1 year. Only 2 possible CM cases were identified in CrAg-negative patients.

CONCLUSIONS

CrAg screening of individuals initiating ART and preemptive fluconazole treatment of CrAg-positive patients resulted in markedly fewer cases of CM compared with historic unscreened cohorts. Studies are needed to refine management of CrAg-positive patients who have high mortality that does not appear to be wholly attributable to cryptococcal disease.

LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcus species. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die.

Burden of tuberculosis at post mortem in inpatients at a tertiary referral centre in sub-Saharan Africa: a prospective descriptive autopsy study

BACKGROUND

Patients with subclinical tuberculosis, smear-negative tuberculosis, extrapulmonary tuberculosis, multidrug-resistant tuberculosis, and asymptomatic tuberculosis are difficult to diagnose and may be missed at all points of health care. We did an autopsy study to ascertain the burden of tuberculosis at post mortem in medical inpatients at a tertiary care hospital in Lusaka, Zambia.

METHODS

Between April 5, 2012, and May 22, 2013, we did whole-body autopsies on inpatients aged at least 16 years who died in the adult inpatient wards at University Teaching Hospital, Lusaka, Zambia. We did gross pathological and histopathological analysis and processed lung tissues from patients with tuberculosis through the GeneXpert MTB/RIF assay to identify patients with multidrug-resistant tuberculosis. The primary outcome measure was specific disease or diseases stratified by HIV status. Secondary outcomes were missed tuberculosis, multidrug-resistant tuberculosis, and comorbidities with tuberculosis. Data were analysed using Pearson χ(2), the Mann-Whitney U test, and binary logistic regression.

FINDINGS

The median age of the 125 included patients was 35 years (IQR 29-43), 80 (64%) were men, and 101 (81%) were HIV positive. 78 (62%) patients had tuberculosis, of whom 66 (85%) were infected with HIV. 35 (45%) of these 78 patients had extrapulmonary tuberculosis. The risk of extrapulmonary tuberculosis was higher among HIV-infected patients than among uninfected patients (adjusted odds ratio 5·14, 95% CI 1·04-24·5; p=0·045). 20 (26%) of 78 patients with tuberculosis were not diagnosed during their life and 13 (17%) had undiagnosed multidrug-resistant tuberculosis. Common comorbidities with tuberculosis were pyogenic pneumonia in 26 patients (33%) and anaemia in 15 (19%).

INTERPRETATION

Increased clinical awareness and more proactive screening for tuberculosis and multidrug-resistant tuberculosis in inpatient settings is needed. Further autopsy studies are needed to ascertain the generalisability of the findings.

FUNDING

UBS Optimus Foundation, EuropeAID, and European Developing Countries Clinical Trials Partnership (EDCTP).