Screening for cryptococcal antigenemia in patients accessing an antiretroviral treatment program in 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.

Cryptococcal meningitis in apparently immunocompetent patients

Cryptococcal meningitis (CM) is an invasive fungal disease that currently poses a threat to human health worldwide, with high morbidity and mortality, particularly in immunocompromised patients. Although CM mainly occurs in HIV-positive patients and other immunocompromised patients, it is also increasingly seen in seemingly immunocompetent hosts. The clinical characteristics of CM between immunocompromised and immunocompetent populations are different. However, few studies have focussed on CM in immunocompetent individuals. This review summarizes the clinical characteristics of apparently immunocompetent CM patients in terms of aetiology, immune pathogenesis, clinical presentation, laboratory data, imaging findings, treatment strategies and prognosis. It is of great significance to further understand the disease characteristics of CM, explore new treatment strategies and improve the prognosis of CM in immunocompetent individuals.

Pathways to care with HIV-associated cryptococcal meningitis in Botswana and Uganda: Findings from a qualitative methods study

HIV-associated cryptococcal meningitis remains a key driver of AIDS-related mortality. Mortality is twice as high in those who present later to care and with severe symptoms such as confusion. We embedded a qualitative methods study within a randomised controlled trial in Gaborone, Botswana and Kampala, Uganda with the aim of understanding pathways to care. We conducted in-depth interviews with trial participants and surrogate decision makers and analysed data thematically. Between January 2020 and June 2021 we interviewed 58 individuals. Pathways to care were prolonged because headaches were disregarded by participants and healthcare workers as a common occurrence with a broad differential diagnosis of predominantly benign aetiologies. There was also a lack of awareness of cryptococcal meningitis, and it was often after HIV was diagnosed or disclosed that the pathway accelerated, resulting in hospital admission. We outline key recommendations to reduce mortality and argue for the integration of social and behavioural interventions within differentiated service delivery models for advanced HIV disease.

Cryptococcal meningitis

Cryptococcus neoformans and Cryptococcus gattii species complexes cause meningoencephalitis with high fatality rates and considerable morbidity, particularly in persons with deficient T cell-mediated immunity, most commonly affecting people living with HIV. Whereas the global incidence of HIV-associated cryptococcal meningitis (HIV-CM) has decreased over the past decade, cryptococcosis still accounts for one in five AIDS-related deaths globally due to the persistent burden of advanced HIV disease. Moreover, mortality remains high (~50%) in low-resource settings. The armamentarium to decrease cryptococcosis-associated mortality is expanding: cryptococcal antigen screening in the serum and pre-emptive azole therapy for cryptococcal antigenaemia are well established, whereas enhanced pre-emptive combination treatment regimens to improve survival of persons with cryptococcal antigenaemia are in clinical trials. Short courses (≤7 days) of amphotericin-based therapy combined with flucytosine are currently the preferred options for induction therapy of cryptococcal meningitis. Whether short-course induction regimens improve long-term morbidity such as depression, reduced neurocognitive performance and physical disability among survivors is the subject of further study. Here, we discuss underlying immunology, changing epidemiology, and updates on the management of cryptococcal meningitis with emphasis on HIV-associated disease.

The SSS revolution in fungal diagnostics: speed, simplicity and sensitivity

INTRODUCTION

Fungal disease has historically presented a diagnostic challenge due to its often non-specific clinical presentations, relative infrequency and reliance on insensitive and time-intensive fungal culture.

SOURCES OF DATA

We present the recent developments in fungal diagnostics in the fields of serological and molecular diagnosis for the most clinically relevant pathogens; developments that have the potential to revolutionize fungal diagnosis through improvements in speed, simplicity and sensitivity. We have drawn on a body of evidence including recent studies and reviews demonstrating the effectiveness of antigen and antibody detection and polymerase chain reaction (PCR) in patients with and without concurrent human immunodeficiency virus infection.

AREAS OF AGREEMENT

This includes recently developed fungal lateral flow assays, which have a low cost and operator skill requirement that give them great applicability to low-resource settings. Antigen detection for Cryptococcus, Histoplasma and Aspergillus spp. are much more sensitive than culture. PCR for Candida spp., Aspergillus spp., Mucorales and Pneumocystis jirovecii is more sensitive than culture and usually faster.

AREAS OF CONTROVERSY

Effort must be made to utilize recent developments in fungal diagnostics in clinical settings outside of specialist centres and integrate their use into standard medical practice. Given the clinical similarities of the conditions and frequent co-infection, further study is required into the use of serological and molecular fungal tests, particularly in patients being treated for tuberculosis.

GROWING POINTS

Further study is needed to clarify the utility of these tests in low-resource settings confounded by a high prevalence of tuberculosis.

AREAS TIMELY FOR DEVELOPING RESEARCH

The diagnostic utility of these tests may require revision of laboratory work flows, care pathways and clinical and lab coordination, especially for any facility caring for the immunosuppressed, critically ill or those with chronic chest conditions, in whom fungal disease is common and underappreciated.

Prevalence and Factors Associated With Cryptoccocal Antigenemia Among Patients With Advanced Human Immunodeficiency Virus in Eastern Uganda: A Facility-Based Cross-sectional Study

Background

Cryptoccocal infection remains an important cause of morbidity and mortality among people with advanced human immunodeficiency virus disease (AHD). In resource-limited settings, there is a paucity of data on cryptoccocal infections. We described the prevalence and factors associated with cryptoccocal antigenemia among people with AHD in Mbale Regional Referral Hospital in Eastern Uganda.

Methods

In this cross-sectional study, data on sociodemographic, clinical, and laboratory characteristics of adults with AHD were collected, and factors associated with cryptoccocal antigenemia were determined using multivariate logistic regression models.

Results

We enrolled 228 participants with a median CD4 cell count of 194/µL (interquartile range, 129-370/µL). The prevalence of cryptoccocal antigen was 10 in 228 (4.4% [95% confidence interval, 2.4%-80%]). CD4 cell counts <100/µL (adjusted odds ratio, 3.70) and poultry keeping were risk factors. The main predictors were headaches (adjusted odds ratio, 1), neck pains (8.817), confusion (6.323), and neck stiffness (676.217). No notable significant associations were found in the multivariate analysis.

Conclusions

The prevalence of cryptoccocal antigen was 4.4%, and antiretroviral therapy was protective.

Diagnostic accuracy of cryptococcal antigen test in pulmonary cryptococcosis: a protocol for a systematic review and meta-analysis

BACKGROUND

The cryptococcal antigen (CrAg) test was proposed as a rapid diagnostic tool to identify cryptococcal meningitis in patients suffering from AIDS. Several studies have demonstrated its diagnostic performance in cryptococcal meningitis. However, the diagnostic performance of the CrAg test in serum or bronchoalveolar lavage fluid in patients with pulmonary cryptococcosis remains uncertain. Therefore, the purpose of this systematic review is to summarise the evidence concerning diagnostic performance of the CrAg test in patients with pulmonary cryptococcosis.

METHODS AND ANALYSIS

Databases such as PubMed, EMBASE, Cochrane Database of Systematic Reviews, Web of Science, ClinicalTrials.gov, International Clinical Trials Registry Platform, Wanfang Database and China National Knowledge Infrastructure will be searched systematically. The titles and abstracts will be reviewed by two independent reviewers. The Quality Assessment of Diagnostic Accuracy Studies 2 tool will be used to evaluate the risk of bias and clinical applicability of each study. Potential sources of heterogeneity will be investigated through visual inspection of the paired forest plots and summary receiver operating characteristic plots. The pooled summary statistics for the area under the curve, sensitivities, specificities, likelihood ratios and diagnostic ORs with 95% CI will be reported.

ETHICS AND DISSEMINATION

The underlying study is based on published articles thus does not require ethical approval. The findings of the systematic review and meta-analysis will be published in a peer-reviewed journal and disseminated in various scientific conferences and seminars.

PROSPERO REGISTRATION NUMBER

CRD42022373321.

Association of Antibody Immunity With Cryptococcal Antigenemia and Mortality in a South African Cohort With Advanced Human Immunodeficiency Virus Disease

BACKGROUND

Asymptomatic cryptococcal antigenemia (positive blood cryptococcal antigen [CrAg]) is associated with increased mortality in individuals with human immunodeficiency virus (HIV) even after adjusting for CD4 count and despite receiving antifungal treatment. The association of antibody immunity with mortality in adults with HIV with cryptococcal antigenemia is unknown.

METHODS

Cryptococcal capsular glucuronoxylomannan (GXM)- and naturally occurring β-glucans (laminarin, curdlan)-binding antibodies were measured in blood samples of 197 South Africans with HIV who underwent CrAg screening and were followed up to 6 months. Associations between antibody titers, CrAg status, and all-cause mortality were sought using logistic and Cox regression, respectively.

RESULTS

Compared with CrAg-negative individuals (n = 130), CrAg-positive individuals (n = 67) had significantly higher IgG1 (median, 6672; interquartile range [IQR], 4696-10 414 vs 5343, 3808-7722 μg/mL; P = .007), IgG2 (1467, 813-2607 vs 1036, 519-2012 μg/mL; P = .01), and GXM-IgG (1:170, 61-412 vs 1:117, 47-176; P = .0009) and lower curdlan-IgG (1:47, 11-133 vs 1:93, 40-206; P = .01) titers. GXM-IgG was associated directly with cryptococcal antigenemia adjusted for CD4 count and antiretroviral therapy use (odds ratio, 1.64; 95% confidence interval [CI], 1.21 to 2.22). Among CrAg-positive individuals, GXM-IgG was inversely associated with mortality at 6 months adjusted for CD4 count and tuberculosis (hazard ratio, 0.50; 95% CI, .33 to .77).

CONCLUSIONS

The inverse association of GXM-IgG with mortality in CrAg-positive individuals suggests that GXM-IgG titer may have prognostic value in those individuals. Prospective longitudinal studies to investigate this hypothesis and identify mechanisms by which antibody may protect against mortality are warranted.

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.

Cryptococcal antigenemia in people living with HIV and AIDS

AIM

To assess the prevalence of cryptococcal antigenemia among people living with HIV/AIDS (PLHA) with CD4 ≤100/mm³.

DESIGN

This observational study was performed on PLHA with laboratory-confirmed CD4 ≤100/mm³. All PLHA were recruited irrespective of their duration of HIV diagnosis, antiretroviral therapy (ART) naïve, or ART failure.

METHODS

The prevalence of cryptococcal antigen (CrAg) was assessed in 102 PLHA, with CD4 ≤100/mm³, using a latex agglutination test on serum samples. All the subjects were followed up for 3 months.

RESULTS

Amongst 102 PLHA, 62 (60.8%) and 40 (39.2%) patients were ART-naïve and ART failures, respectively, with 2.9% (n = 3) having clinical features of meningitis and 6.8% (n = 7) patients being asymptomatic CrAg-positive. At the 3 month follow-up, total mortality was 10.8%, of which 33.3% and 8.8% were among CrAg-positive and negative patients (p = 0.05). Mortality in asymptomatic and meningitis symptomatic CrAg-positive patients was 1.03% (n = 1) and 2.06% (n = 2), respectively. Of note, five patients were lost to follow-up.

CONCLUSION

Cryptococcal antigenemia is common among patients with CD4 ≤100/mm³ who were either ART naïve or had treatment failure. Asymptomatic patients who underwent pre-emptive therapy demonstrated good clinical outcomes.

Six months survival and risk factors for attrition for patients detected with cryptococcal antigenemia through screening in Malawi

MAIN OBJECTIVE

A cohort of adult Malawian people living with HIV (PLHIV) testing positive for cryptococcal antigenemia was observed and followed to determine the outcomes and risk factors for attrition.

METHODS CONCEPT

Eligible PLHIV were enrolled at 5 health facilities in Malawi, representing different levels of health care. ART naïve patients, ART defaulters returning to care, and patients with suspected or confirmed ART treatment failure with CD4 <200 cells/μL or clinical stage 3 or 4 were enrolled and received CrAg tests on whole blood specimens from August 2018 to August 2019. Hospitalized PLHIV were enrolled and tested for CrAg from January 2019 to August 2019, regardless of CD4 or clinical stage. Patients with cryptococcal antigenemia were managed per Malawian clinical guidelines and were followed up for six months. Survival and risk factors for attrition at six months were assessed.

RESULTS

A total of 2146 patients were screened and 112 (5.2%) had cryptococcal antigenemia. Prevalence ranged from 3.8% (Mzuzu Central Hospital) to 25.8% (Jenda Rural Hospital). Of the 112 patients with antigenemia, 33 (29.5%) were diagnosed with concurrent CM at the time of enrollment. Six-month crude survival of all patients with antigenemia (regardless of CM status) ranged from 52.3% (assuming lost-to-follow-up (LTFU) patients died) to 64.9% (if LTFU survived). Patients who were diagnosed with concurrent CM by CSF test had poor survival (27.3-39.4%). Patients with antigenemia who were not diagnosed with concurrent CM had 71.4% (if LTFU died)- 89.8% (if LTFU survived) survival at six months. In adjusted analyses, patients with cryptococcal antigenemia detected after admission to inpatient care (aHR: 2.56, 1.07-6.15) and patients with concurrent CM at the time of positive antigenemia result (aHR: 2.48, 1.04-5.92) had significantly higher hazard of attrition at six months.

CONCLUSIONS

Overall, our findings indicate a need for routine access to CrAg screening and pre-emptive fluconazole treatment as a way to detect cryptococcal antigenemia and prevent CM in outpatient and inpatient settings. Rapid access to diagnosis and treatment for cryptococcal meningitis (CM) with gold-standard antifungals is needed to improve survival of patients with advanced HIV in Malawi.

Laboratory Evaluation of the VISITECT Advanced Disease Semiquantitative Point-of-Care CD4 Test

BACKGROUND

Advanced HIV disease (AHD; CD4 counts <200 cells/µL) remains common in many low- and middle-income settings. An instrument-free point-of-care test to rapidly identify patients with AHD would facilitate implementation of the World Health Organization (WHO) recommended package of care. We performed a laboratory-based validation study to evaluate the performance of the VISITECT CD4 Advanced Disease assay in Botswana.

SETTING

A laboratory validation study.

METHODS

Venous blood samples from people living with HIV having baseline CD4 testing in Gaborone, Botswana, underwent routine testing using flow cytometry, followed by testing with the VISITECT CD4 Advanced Disease assay by a laboratory scientist blinded to the flow cytometry result with a visual read to determine whether the CD4 count was below 200 cells/µL. A second independent investigator conducted a visual read blinded to the results of flow cytometry and the initial visual read. The sensitivity and specificity of the VISITECT for detection of AHD were determined using flow cytometry as a reference standard, and interrater agreement in VISITECT visual reads assessed.

RESULTS

One thousand fifty-three samples were included in the analysis. The VISITECT test correctly identified 112/119 samples as having a CD4 count <200 cells/µL, giving a sensitivity of 94.1% (95% confidence interval: 88.3% to 97.6%) and specificity of 85.9% (95% confidence interval: 83.5% to 88.0%) compared with flow cytometry. Interrater agreement between the 2 independent readers was 97.5%, Kappa 0.92 ( P < 0.001).

CONCLUSIONS

The VISITECT CD4 advanced disease reliably identified individuals with low CD4 counts and could facilitate implementation of the WHO recommended package of interventions for AHD.

Prevalence and Associated Factors of Cryptococcal Antigenemia in HIV-Infected Patients with CD4 < 200 Cells/µL in São Paulo, Brazil: A Bayesian Analysis

Cryptococcosis is a severe life-threatening disease and a major cause of mortality in people with advanced AIDS and CD4 ≤ 100 cells/µL. Considering the knowledge gap regarding the benefits of routine application of antigenemia tests in HIV-infected patients with 100−200 CD4 cells/µL for the prevention of cryptococcal meningitis (CM), we aimed to evaluate the prevalence of positive antigenemia through lateral flow assay (LFA) and associated factors in HIV-infected patients with CD4 < 200 cells/µL. Our findings of 3.49% of positive LFA (LFA+) patients with CD4 < 100 cells/µL and 2.24% with CD4 between 100−200 cells/µL have been included in a Bayesian analysis with 12 other studies containing similar samples worldwide. This analysis showed a proportion of 3.6% LFA+ patients (95% credible interval-Ci [2.5−5.7%]) with CD4 < 100 cells/µL and 1.1% (95%Ci [0.5−4.3%]) with CD4 between 100−200 cells/µL, without statistical difference between these groups. The difference between mortality rates in LFA+ and negative LFA groups was e = 0.05013. Cryptococcoma and CM were observed in the LFA+ group with 100−200 and <100 CD4 cells/µL, respectively. Considering the benefits of antifungal therapy for LFA+ patients, our data reinforced the recommendation to apply LFA as a routine test in patients with 100−200 CD4 cells/µL aiming to expand cost-effectiveness studies in this group.

Pulmonary Cryptococcosis

Pulmonary cryptococcosis describes an invasive lung mycosis caused by Cryptococcus neoformans or Cryptococcus gattii complex. It is often a high-consequence disease in both immunocompromised and immunocompetent populations, and may be misdiagnosed as pulmonary malignancy, leading to a delay in therapy. Epidemiology follows that of cryptococcal meningoencephalitis, with C. gattii infection more common in certain geographic regions. Diagnostic tools include histopathology, microscopy and culture, and the detection of cryptococcal polysaccharide antigen or Cryptococcus-derived nucleic acids. All patients with lung cryptococcosis should have a lumbar puncture and cerebral imaging to exclude central nervous system disease. Radiology is key, both as an adjunct to laboratory testing and as the initial means of detection in asymptomatic patients or those with non-specific symptoms. Pulmonary cryptococcomas (single or multiple) may also be associated with disseminated disease and/or cryptococcal meningitis, requiring prolonged treatment regimens. Optimal management for severe disease requires extended induction (amphotericin B and flucytosine) and consolidation therapy (fluconazole) with close clinical monitoring. Susceptibility testing is of value for epidemiology and in regions where relatively high minimum inhibitory concentrations to azoles (particularly fluconazole) have been noted. Novel diagnostic tools and therapeutic agents promise to improve the detection and treatment of cryptococcosis, particularly in low-income settings where the disease burden is high.

Diagnostic Accuracy of Point of Care Cryptococcal Antigen Lateral Flow Assay in Fingerprick Whole Blood and Urine Samples for the Detection of Asymptomatic Cryptococcal Disease in Patients with Advanced HIV Disease

Cryptococcal disease (CD) is a leading cause of mortality among individuals with advanced HIV disease (AHD). Screening with serum cryptococcal antigen (sCrAg) lateral flow assay (LFA) enables early detection of subclinical disease but requires venipuncture and laboratory processing. Clinic-based point of care (POC) CrAg screening tests using urine or fingerprick whole blood could facilitate early diagnosis of CD. We evaluated the diagnostic performance of POC clinic-based fingerprick whole blood and urine CrAg compared to the gold standard laboratory sCrAg LFA in screening for CD among asymptomatic individuals with CD4 counts of <200 cells/μL in Harare, Zimbabwe. sCrAg positive participants who consented to a lumbar puncture also had cerebrospinal fluid (CSF) CrAg testing and titers for CSF-positive specimens. A total of 1,333 individuals were screened, and over half (56.6%) were males. The median (interquartile range) CD4 count was 27.5 (11–46) cells/μL. We found a sensitivity of 63.8% (95% CI: 54.8–72.1) and specificity of 84.0% (95% CI: 81.7–86.0) for urine CrAg, and a sensitivity of 48.0% (95% CI: 39.1–57.1) and specificity of 99.5% (95% CI: 98.9–99.8) was found for fingerprick whole blood. The sensitivity of both POC CrAg tests increased in individuals with sCrAg titers of ≥1:160, CD4 count of <50 cells/μL and disseminated central nervous system (CNS) disease. Clinic-based POC urine and fingerprick whole blood CrAg testing performed better in screening for CD among AHD patients with CNS disease. More sensitive assays to identify AHD patients with asymptomatic CD are needed.

IMPORTANCE Cryptococcal disease (CD) remains a leading cause of morbidity and mortality among individuals with advanced HIV disease (AHD). Identifying point of care (POC) approaches to screening for CD in asymptomatic individuals is important to guide therapeutic management. We evaluated the use of POC fingerprick whole blood and urine testing for cryptococcal disease in patients with AHD as compared with laboratory-based serum antigen testing. POC fingerprick whole blood and urine testing had low sensitivity and specificity in asymptomatic individuals with AHD. Most analysis has focused on evaluating test performance in symptomatic individuals. Here we show that POC testing with whole blood and urine samples should not be used to screen for asymptomatic CD in AHD.

Cost-effectiveness of single-dose AmBisome preemptive treatment for the prevention of cryptococcal meningitis in African low and middle-income countries

Cryptococcal antigen (CrAg) screening is recommended for patients with advanced HIV to reduce AIDS-related mortality. For asymptomatic CrAg-positive persons, fluconazole preemptive therapy is standard, despite a ∼25% failure rate. Single-dose liposomal amphotericin B (AmBisome) is non-inferior to standard treatment for cryptococcal meningitis. We evaluate the threshold of efficacy necessary for AmBisome + fluconazole to be cost-effective as preemptive therapy for CrAg-positive persons. We created a decision analytic model to evaluate CrAg screening and treatment in HIV-infected persons with CD4 < 100 cells/µL. Costs were estimated for screening, preemptive therapy, and hospitalization for an example low-income country (Uganda) and middle-income country (South Africa). We used a discounted price range of AmBisome® at ${\$}$16.25 to ${\$}$40 per 50 mg vial for both Uganda and South Africa. We estimated AmBisome efficacy from 75% to 95%. Parameter assumptions were based on prospective CrAg screening studies and clinical trials in Africa. Disability adjusted life years (DALYs) were calculated using the age-specific life expectancy in Uganda, per WHO Global Health Observatory data. We modeled the theoretical efficacy of adjunctive AmBisome to determine cost per DALY averted. In South Africa, at ${\$}$16.25 per vial cost and a minimum efficacy of 85%, adjunctive AmBisome is cost-saving compared to fluconazole monotherapy. Compared to fluconazole preemptive therapy in Uganda, AmBisome + fluconazole would cost ${\$}$475, ${\$}$220, or ${\$}$136 per DALY averted if meningitis-free survival efficacy was 80%, 85%, or 90% at ${\$}$24 per vial cost. Investing in AmBisome may be cost-effective in low-income settings compared to using fluconazole preemptive therapy alone, if efficacy is 85% or greater. AmBisome preemptive therapy appears more cost-efficient in middle-income settings where hospitalization costs for meningitis, and GDP per capita are higher.

Survival following screening and preemptive antifungal therapy for subclinical cryptococcal disease in advanced HIV infection

OBJECTIVES

Our study's primary objective was to compare 1-year survival rates between serum cryptococcal antigen (sCrAg)-positive and sCrAg-negative HIV-positive individuals with CD4+ cell counts less than 100 cells/μl without symptoms of meningitis in Zimbabwe.

DESIGN

This was a prospective cohort study.

METHODS

Participants were enrolled as either sCrAg-positive or sCrAg-negative and followed up for 52 weeks or less, with death as the outcome. Lumbar punctures were recommended to all sCrAg-positives and inpatient management with intravenous amphotericin B and high-dose fluconazole was recommended to those with disseminated Cryptococcus. Antiretroviral therapy was initiated immediately in sCrAg-negatives and after at least 4 weeks following initiation of antifungals in sCrAg-positives. Multivariable logistic regression models were used to determine risk factors for mortality.

RESULTS

We enrolled 1320 participants and 130 (9.8%) were sCrAg positive, with a median sCrAg titre of 1 : 20. Sixty-six (50.8%) sCrAg-positives had lumbar punctures and 16.7% (11/66) had central nervous system (CNS) dissemination. Cryptococcal blood cultures were performed in 129 sCrAg-positives, with 10 (7.8%) being positive. One-year (48-52 weeks) survival rates were 83.9 and 76.1% in sCrAg-negatives and sCrAg-positives, respectively, P = 0.011. Factors associated with increased mortality were a positive sCrAg, CD4+ cell count less than 50 cells/μl and having presumptive tuberculosis (TB) symptoms.

CONCLUSION

Our study reports a high prevalence of subclinical cryptococcal antigenemia and reiterates the importance of TB and a positive sCrAg as risk factors for mortality in advanced HIV disease (AHD). Therefore, TB and sCrAg screening remains a crucial component of AHD package, hence it should always be part of the comprehensive clinical evaluation in AHD patients.

Cryptococcal meningoencephalitis: time for action

Cryptococcal meningoencephalitis was first described over a century ago. This fungal infection is preventable and treatable yet continues to be associated with excessive morbidity and mortality. The largest burden of disease resides in people living with HIV in low-income and middle-income countries. In this group, mortality with the best antifungal induction regimen (7 days of amphotericin B deoxycholate [1·0 mg/kg per day] and flucytosine [100·0 mg/kg per day]) in a clinical trial setting was 24% at 10 weeks. The world is now at an inflection point in terms of recognition, research, and action to address the burden of morbidity and mortality from cryptococcal meningoencephalitis. However, the scope of interventional programmes needs to increase, with particular attention to implementation science that is specific to individual countries. This Review summarises causes of excessive mortality, interventions with proven survival benefit, and gaps in knowledge and practice that contribute to the ongoing high death toll from cryptococcal meningoencephalitis. TRANSLATIONS: For the Vietnamese and Chichewa translations of the abstract see Supplementary Materials section.

Laboratory Reflex and Clinic-Based Point-of-Care Cryptococcal Antigen Screening for Preventing Meningitis and Mortality Among People Living With HIV

INTRODUCTION

Cryptococcosis remains a leading cause of meningitis and mortality among people living with HIV (PLHIV) worldwide. We sought to evaluate laboratory-based cryptococcal antigen (CrAg) reflex testing and a clinic-based point-of-care (POC) CrAg screening intervention for preventing meningitis and mortality among PLHIV in South Africa.

METHODS

We conducted a prospective pre-post intervention study of adults presenting for HIV testing in Umlazi township, South Africa, over a 6-year period (2013-2019). Participants were enrolled during 3 phases of CrAg testing: CrAg testing ordered by a clinician (clinician-directed testing, 2013-2015); routine laboratory-based CrAg reflex testing for blood samples with CD4 ≤100 cells/mm3 (laboratory reflex testing, 2015-2017); and a clinic-based intervention with POC CD4 testing and POC CrAg testing for PLHIV with CD4 ≤200 cells/mm3 with continued standard-of-care routine laboratory reflex testing among those with CD4 ≤100 cells/mm3 (clinic-based testing, 2017-2019). The laboratory and clinical teams performed serum CrAg by enzyme immunoassay and lateral flow assay (Immy Diagnostics, Norman, OK). We followed up participants for up to 14 months to compare associations between baseline CrAg positivity, antiretroviral therapy and fluconazole treatment initiation, and outcomes of cryptococcal meningitis, hospitalization, and mortality.

RESULTS

Three thousand one hundred five (39.4%) of 7877 people screened were HIV-positive, of whom 908 had CD4 ≤200 cells/mm3 and were included in the analyses. Laboratory reflex and clinic-based testing increased CrAg screening (P < 0.001) and diagnosis of CrAg-positive PLHIV (P = 0.011). When compared with clinician-directed testing, clinic-based CrAg testing showed an increase in the number of PLHIV diagnosed with cryptococcal meningitis (4.5% vs. 1.5%; P = 0.059), initiation of fluconazole preemptive therapy (7.2% vs. 2.5%; P = 0.010), and initiation of antiretroviral therapy (96.8% vs. 91.3%; P = 0.012). Comparing clinic-based testing with laboratory reflex testing, there was no significant difference in the cumulative incidence of cryptococcal meningitis (4.5% vs. 4.1%; P = 0.836) or mortality (8.1% vs. 9.9%; P = 0.557).

CONCLUSIONS

Laboratory reflex and clinic-based CrAg testing facilitated the diagnosis of HIV-associated cryptococcosis and fluconazole initiation but did not reduce cryptococcal meningitis or mortality. In this nonrandomized cohort, clinical outcomes were similar between laboratory reflex testing and clinic-based POC CrAg testing.

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.

Successful Isavuconazole Salvage Therapy for a Cryptococcus deuterogattii (AFLP6/VGII) Disseminated Infection in a European Immunocompetent Patient

Members of the Cryptococcus gattii species complex are notorious causes of cryptococcosis as they often cause severe, life-threatening infections. Here we describe a case of a severe disseminated C. deuterogattii infection in a previously healthy patient who was initially treated with amphotericin B, 5-fluorocytosine and fluconazole, which led to a good neurological response, but the infection in the lungs remained unaltered and was not completely resolved until switching the antifungal therapy to isavuconazole. The infection was likely acquired during a one-month stay at the Azores Islands, Portugal. Environmental sampling did not yield any cryptococcal isolate; therefore, the source of this apparent autochthonous case could not be determined. Molecular typing showed that the cultured C. deuterogattii isolates were closely related to the Vancouver Island outbreak-genotype.

Screening for Cryptococcal Antigenemia and Burden of Cryptococcosis at the Time of HIV Diagnosis: A Retrospective Multicenter Study

Introduction

Screening for cryptococcal antigen (CrAg) is recommended for people living with HIV (PLWH) who present with low CD4 lymphocyte counts. Real-world experience is important to identify gaps between the guidelines and clinical practice. We investigated the trends of CrAg testing and prevalence of cryptococcal antigenemia among PLWH at the time of HIV diagnosis and the related mortality in Taiwan from 2009 to 2018.

Methods

Medical records of newly diagnosed PLWH seeking care at six medical centers around Taiwan between 2009 and 2018 were reviewed. The annual trends of PLWH who had CrAg testing and cryptococcal antigenemia were examined by Cochran-Armitage test. Among PLWH with CD4 < 200 cells/µl, timing of CrAg testing was analyzed for association with 12-month all-cause mortality in Kaplan-Meier plots and in a Cox proportional hazards model after adjustments.

Results

Among 5372 included PLWH, 1150 (21.4%) presented with baseline CD4 < 100 cells/µl, and this proportion had decreased during the study period [from 108 (29.3%) in 2009 to 93 (22.3%) in 2018 (P = 0.039)]. The overall prevalence of cryptococcal antigenemia was 7.8% among PLWH with CD4 < 100 cells/µl, which remained stable during the 10-year study period (P = 0.356) and was 2.6% among PLWH with CD4 100–199 cells/µl. The uptake of CrAg testing had increased from 65.7% in 2009 to 78.0% in 2018 (P = 0.002) among PLWH with CD4 < 100 cells/µl. Late CrAg testing, defined by 14 days or later after HIV diagnosis, was associated with increased risk of 12-month mortality compared to early CrAg testing (adjusted hazard ratio 2.028, 95% CI 1.109–3.708).

Conclusions

Burden of cryptococcosis remained high among PLWH with low CD4 lymphocyte counts in Taiwan. Uptake of CrAg screening among late HIV presenters was still suboptimal and delayed. Late CrAg testing was associated with a higher mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00451-5.

Outcomes of Reflex Cryptococcal Antigen (CrAg) Screening in Human Immunodeficiency Virus (HIV)-Positive Patients With CD4 Counts of 100-200 Cells/µL in Botswana

Increasing the CD4-count threshold for cryptococcal antigen (CrAg) screening from ≤100 to ≤200 cells/µL resulted in a 3-fold increase in numbers screened. CrAg-prevalence was 3.5% at CD4 101-200 and 6.2% ≤100 cells/µL. Six-month mortality was 21.4% (9/42) in CrAg-positive CD4 ≤100 cells/µL and 3.2% (1/31) in CrAg-positive CD4 101-200 cells/µL.

Evaluation of a Cryptococcal Antigen Lateral Flow Assay and Cryptococcal Antigen Positivity at a Large Public Hospital in Atlanta, Georgia

BACKGROUND

Cryptococcus neoformans is a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected persons worldwide, and there are scarce recent data on cryptococcal antigen (CrAg) positivity in the United States We sought to determine the frequency of cryptococcal disease and compare the performance of a CrAg lateral flow assay (LFA) versus latex agglutination (LA) test.

METHODS

All patients from Grady Health System in Atlanta who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg testing as part of clinical care from November 2017 to July 2018 were included. Percentage positivity and test agreement were calculated.

RESULTS

Among 467 patients, 557 diagnostic tests were performed; 413 on serum and 144 on CSF. The mean age was 44 years, and most were male (69%) and had HIV (79%). Twenty-four (6.4%, 95% confidence interval [CI] = 4.1-9.4) patients were serum CrAg positive, and 8 (5.8%, 95% CI = 2.6-11.2) individuals tested positive for CSF CrAg. Although overall agreement between the LA and LFA was substantial to high for CSF (κ = 0.71, 95% CI = 0.51-0.91) and serum (κ = 0.93, 95% CI = 0.86-1.00), respectively, there were important discrepancies. Five patients had false-positive CSF LA tests that affected clinical care, and 4 patients had discordant serum tests.

CONCLUSIONS

We found a moderately high proportion of cryptococcal disease and important discrepancies between the LA test and LFA. Clinical implications of these findings include accurate detection of serum CrAg and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events.

Prevalence of Cryptococcal Antigenemia and Associated Factors among HIV/AIDS Patients at Felege-Hiwot Referral Hospital, Bahir Dar, Northwest Ethiopia

Background

Cryptococcosis is the most common opportunistic fungal infection. High morbidity and mortality are frequently observed among hospitalized HIV/AIDS patients, particularly having CD4 count ≤100 cells/μl. Therefore, this study aimed to determine the prevalence of cryptococcal antigenemia and associated factors among HIV/AIDS patients.

Methods

A hospital-based cross-sectional study was conducted among 140 HIV/AIDS patients. A cryptococcal antigen test was performed for all patients along with medical chart and laboratory registration book review. Cryptococcal antigen was detected from serum by using Remel Cryptococcal Antigen Test Kit. Data related to possible associated factors were extracted from patients' charts and laboratory registration book. Data were coded, entered, and analyzed using SPSS version 20. Logistic regression analysis was done to see the association between dependent and independent variables. A P value <0.05 was considered statistically significant. Finally, data were presented in the form of texts, figures, and tables.

Result

Among 140 serum cryptococcal antigenemia-tested study subjects, 16 (11.43%) were positive for serum cryptococcal antigen. Of them, 43.8% (7/16) were pulmonary tuberculosis coinfected, 31.2% (5/16) were extrapulmonary tuberculosis positive, and 25% (4/16) had bacterial bloodstream infections. In addition, 68.7% (11/16) had CD4 count less than 100 cells/μl, 18.7% (3/16) had CD4 count 100–150 cells/μl, 50% (8/16) were antiretroviral therapy defaulters, and 31.3% (5/16) were naïve. In this study, the majority, 75% (12/16), of the serum cryptococcal antigen-positive subjects were clinical stage IV. Of the assessed associated factors, tuberculosis coinfection (AOR: 0.04; 95% CI [0.005–0.25]) and antiretroviral therapy status (AOR: 0.02; 95% CI [0.001–0.5]) were significantly associated factors enhancing serum cryptococcal antigenemia.

Conclusion

In this study, the high rate of cryptococcal antigenemia was observed among hospitalized HIV/AIDS patients, and it is alarming and highlights the need for improving CD4 status, expanding serum cryptococcal antigen screening, and strengthening regular cryptococcal antigenemia surveillance systems.

Diagnostic Accuracy of the Biosynex CryptoPS Cryptococcal Antigen Semiquantitative Lateral Flow Assay in Patients with Advanced HIV Disease

High cryptococcal antigen (CrAg) titers in blood are associated with subclinical meningitis and mortality in CrAg-positive individuals with advanced HIV disease (AHD). We evaluated a novel semiquantitative lateral flow assay (LFA), CryptoPS, that may be able to identify individuals with high CrAg titers in a cohort of AHD patients undergoing CrAg screening. In a prospective cohort of patients with AHD (CD4 cell count, ≤200/μl) receiving CD4 count testing, whole blood was tested for CrAg by CryptoPS and the IMMY LFA; the two assays were conducted by two different operators, each blind to the results of the other assay.

High cryptococcal antigen (CrAg) titers in blood are associated with subclinical meningitis and mortality in CrAg-positive individuals with advanced HIV disease (AHD). We evaluated a novel semiquantitative lateral flow assay (LFA), CryptoPS, that may be able to identify individuals with high CrAg titers in a cohort of AHD patients undergoing CrAg screening. In a prospective cohort of patients with AHD (CD4 cell count, ≤200/μl) receiving CD4 count testing, whole blood was tested for CrAg by CryptoPS and the IMMY LFA; the two assays were conducted by two different operators, each blind to the results of the other assay. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CryptoPS were assessed against the IMMY LFA as a reference. CryptoPS low-titer (T1 band) and high-titer (T2 band) results were compared with IMMY LFA titers obtained through serial dilution. A total of 916 specimens were tested. The sensitivity of the CryptoPS assay was 61.0% (25/41) (95% confidence interval [95% CI], 44.5 to 75.8%), its specificity was 96.6% (845/875) (95% CI, 95.1 to 97.7%), its PPV was 45.5% (95% CI, 32.0 to 59.4%), and its NPV was 98.1% (95% CI, 97.0 to 98.9%). All (16/16) CryptoPS false-negative results were obtained for samples with IMMY titers of ≤1:160. Of 29 patients (30 specimens) who tested positive by CryptoPS but negative by the IMMY LFA, none developed cryptococcal meningitis over 3 months of follow-up without fluconazole. Median CrAg titers were 1:20 (interquartile range [IQR], 0 to 1:160) in CryptoPS T1-positive samples and 1:2,560 (IQR, 1:1,280 to 1:10,240) in T2-positive samples. We conclude that the diagnostic accuracy of the CryptoPS assay was suboptimal in the context of CrAg screening, with poor sensitivity at low CrAg titers. However, the CryptoPS assay reliably detected individuals with high titers, which are associated with poor outcomes.

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.

Estimates of serious fungal infection burden in Côte d'Ivoire and country health profile

Due to limited access to more powerful diagnostic tools, there are few data on the burden of fungal infections in Côte d'Ivoire, despite a high HIV and TB burden and many cutaneous diseases. Here we estimate the burden of serious fungal infections in this sub-Saharan country with a health profiling description. National demographics were used and PubMed searches to retrieve all published articles on fungal infections in Côte d'Ivoire and other bordering countries in West Africa. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology by LIFE (www.LIFE-Worldwide.org). The population of Côte d'Ivoire is around 25 million; 37% are children (≤14 years), and 9% are>65 years. Tinea capitis in children is common, measured at 13.9% in 2013. Considering the prevalence of HIV infection (2.6% of the population, a total of ∼500,000) and a hospital incidence of 12.7% of cryptococcosis, it is estimated that 4590 patients per year develop cryptococcosis. For pneumocystosis, it is suggested that 2640 new cases occur each year with the prevalence of 11% of newly diagnosed HIV adults, and 33% of children with HIV/AIDS. Disseminated histoplasmosis is estimated a 1.4% of advanced HIV disease - 513 cases. An estimated 6568 news cases of chronic pulmonary aspergillosis (CPA) occur after pulmonary tuberculosis (a 5-year prevalence of 6568 cases [26/100,000]). Allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS) were estimated in 104/100,000 and 151/100,000 respectively, in 1,152,178 adult asthmatics. Vulvovaginal candidiasis (VVC) is common and recurrent VVC affects ∼6% of women in their fertile years - 421,936 women. An unknown number develop candidaemia and invasive aspergillosis. The annual incidence of fungal keratitis is estimated at 3350. No cases of sporotrichosis, mucormycosis and chromoblastomycosis are described, although some cases of mycetoma and Conidiobolus infection have been reported. This study indicates that around to 7.25% (1.8 million) of the population is affected by a serious fungal infection, predominently tinea capitis in children and rVVC in women. These data should be used to inform epidemiological studies, diagnostic needs and therapeutic strategies in Côte d'Ivoire.

HIV-associated Cryptococcal Meningitis: a Review of Novel Short-Course and Oral Therapies

Purpose of review

HIV-associated cryptococcal meningitis remains a significant public health problem in parts of Africa and Asia and a major cause of AIDS-related mortality, accounting for 15% of all AIDS-related deaths worldwide. Cryptococcal meningitis is uniformly fatal if untreated, and access to antifungal therapy in regions with the highest burden is often limited. Outcomes with fluconazole monotherapy are poor, and induction treatment with amphotericin B and high-dose fluconazole for 2 weeks is associated with significant drug-related toxicities and prolonged hospital admissions. This review focuses on the potential of novel short-course and oral combination therapies for cryptococcal meningitis.

Recent findings

Recent clinical trials have shown that shorter courses of amphotericin, if paired with oral flucytosine, rather than fluconazole, can achieve non-inferior mortality outcomes. In addition, an oral combination of fluconazole and flucytosine is a potential alternative. Liposomal amphotericin B may further simplify treatment; it is associated with fewer drug-related toxicities, and a recent phase II randomised controlled trial demonstrated that a single, high dose of liposomal amphotericin is non-inferior to 14 standard daily doses at clearing Cryptococcus from cerebrospinal fluid. This has been taken forward to an ongoing phase III, clinical endpoint study.

Summary

The incidence and mortality associated with cryptococcal meningitis is still unacceptably high. There is evidence supporting the use of short-course amphotericin B and oral combination antifungal treatment regimens for cryptococcal meningitis (CM). Ongoing research into short-course, high-dose treatment with liposomal amphotericin may also help reduce the impact of this devastating disease.

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 infection in HIV-infected patients with CD4+ T-cell counts under 100/μL diagnosed in a high-income country: a multicentre cohort study

OBJECTIVES

The World Health Organization recommends routinely screening HIV-infected patients with CD4⁺ T-cell counts <100/μL for cryptococcal infection to prevent cryptococcal meningitis (CM), based on studies in Sub-Saharan Africa where the prevalence of positive cryptococcal antigen (CrAg+) is ≥ 3% in this subgroup. Data about such prevalence in Spain are unavailable and rare in other European countries. Thus, the Spanish AIDS Study Group guidelines do not recommend routinely screening. We aim to determine the prevalence and outcomes of cryptococcal infection in this subgroup of patients in Spain.

METHODS

We determined CrAg using a lateral flow assay in banked plasma from participants in the cohort of the Spanish AIDS Research Network. Eligible patients had CD4⁺ T-cell counts ≤100/μL at the time of plasma collection and a follow-up >4 weeks, unless they died.

RESULTS

We included 576 patients from June 2004 to December 2017. Of these, 43 were CrAg+ for an overall prevalence of 7.5%. There were no differences depending on birthplace. The CrAg+ was independently associated with a higher mortality at eight weeks (hazard ratio (HR) 5.36, 95% confidence interval (CI) 1.46-19.56) and 6 months (HR 3.12, 95% CI 1.19-8.21). CM was reported in 10 of the 43 CrAg+ patients. There were no cases among negatives. Five patients had CM when the plasma was collected and five developed it during the follow-up. The number of subjects needed to screen to anticipate the diagnosis of one CM case was 114.

CONCLUSIONS

The CrAg+ prevalence among HIV-infected patients with CD4⁺ T-cell counts ≤100/μL diagnosed in Spain, both immigrants and native-born Spanish, is >7%. Consequently, the Spanish AIDS Study Group guidelines have to be updated and recommend routine screening for cryptococcal infection in these patients. Future studies should explore whether this recommendation could be firmly applied to other European populations.

Epidemiology of Cryptococcus and cryptococcosis in Western Africa

Cryptococcosis is a serious and sometimes fatal fungal disease caused by Cryptococcus species. Worldwide, it is estimated to kill over 180 000 annually, with 75% of deaths occurring in sub-Saharan Africa. Though cryptococcal infections are rare in otherwise healthy individuals, there have been reported cases in immunocompetent persons. Most cases occur in individuals who have weakened immune systems, particularly those with advanced HIV/AIDS, thus making West Africa a potential hotspot of the disease. Despite this, there is no recent review article with a focus on published findings on cryptococcosis in Western Africa. Common clinical symptoms include chest pain, dry cough, headache, nausea, confusion, fever, fatigue and stiffness of the neck/neurological impairment. The CNS and the lung remain its preferred target even though rare cases of attack on other parts of the body were reported in this review. Cryptococcal antigen screening and India ink preparation were the most commonly used diagnostic methods. Repeated isolation from environmental samples was observed. Overall, data on the clinical prevalence of Cryptococcus are scarce and variable in the region. The environmental prevalence ranges from 2.3% to 22%. This review covers all published research findings on cryptococcosis in West Africa till date. The epidemiological data will likely be of interest to clinicians within and outside the continent. The nations covered in this review include the following: Benin Republic, Burkina Faso, Cote d'ivoire, Ghana, Guinea, Guinea- Bissau, Mali, Nigeria, Senegal and Sierra Leone. More studies are warranted to fill the observed gaps on the epidemiology of Cryptococcus in the region.

Potential missed opportunities for diagnosis of cryptococcosis and the association with mortality: A cohort study

BACKGROUND

Cryptococcosis is one of the most common life-threatening opportunistic mycoses worldwide. Insidious presentation and slow onset of symptoms make it difficult to recognize, complicating the diagnostic process. Delays in diagnosis may lead to increased mortality. We aim to determine the frequency of missed opportunities for diagnosis of cryptococcosis and its effects on mortality.

METHODS

To estimate the proportion of individuals with a potentially missed diagnosis for cryptococcosis in hospitalized patients, we conducted a retrospective cohort study using the Healthcare Cost and Utilization Project State Inpatient Databases from 2005 to 2015 from eight states. All hospitalized adult patients diagnosed with cryptococcal infection or cryptococcal meningitis were included. Potentially missed diagnoses were defined as admissions coded for a procedure or diagnosis suggestive of cryptococcosis in the 90-days prior to the initial cryptococcosis admission. Generalized estimating equations models were used to evaluate the association between underlying comorbidities and potential missed diagnosis of cryptococcosis and 90-day all-cause in-hospital mortality.

FINDINGS

Of 5,354 patients with cryptococcosis, 2,445 (45·7%) were people living with HIV (PLWH). Among PLWH, 493/2,445 (20·2%) had a potentially missed diagnosis, of which 83/493 (16·8%) died while hospitalized compared with 265/1,952 (13·6%) of those without a potentially missed diagnosis (relative risk [RR] 1·04, 95% CI 0·99-1·09). Among HIV-negative patients, 977/2,909 (33·6%) had a potentially missed diagnosis, of which 236/977 (24·2%) died while hospitalized compared with 298/1,932 (15·4%) of those not missed (RR 1·12, 95% CI 1·07-1·16).

INTERPRETATION

Missed opportunities to diagnose cryptococcosis are common despite highly efficacious diagnostic tests and are associated with increased risk of 90-day mortality in HIV-negative patients. A high index of clinical suspicion is paramount to promptly diagnose, treat, and improve cryptococcosis-related mortality.

FUNDING

National Center for Advancing Translational Sciences, Washington University Institute of Clinical and Translational Sciences, and the Agency for Healthcare Research and Quality.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

Disseminated Histoplasmosis in HIV-Infected Patients: A Description of 34 Years of Clinical and Therapeutic Practice

Disseminated histoplasmosis is the main AIDS-defining infection of French Guiana. We aim to describe our therapeutic experience for 349 patients with disseminated histoplasmosis between 1 January 1981 and 10 January 2014 in French Guiana. Survival, delays for treatment initiation, duration of induction therapy, and associated initial treatments are described. The death rate was 14.9 per 100 person-years, with an early drop in survival. Among those who died, >1/3 died within a year of HIV diagnosis, and ¾ of all patients with histoplasmosis had been diagnosed for HIV within a year. As induction treatment, 29% received liposomal amphotericin B, 12.9% received deoxycholate amphotericin B, 54% received itraconazole alone, and 21.8% received liposomal amphotericin B and itraconazole. The median delay between symptoms-onset and hospitalization was 19.5 days (IQR = 5–105). Liposomal amphotericin B or itraconazole was initiated shortly after admission. Treatment initiation was often presumptive for liposomal amphotericin B (27%) and itraconazole (20%). The median duration of liposomal amphotericin B treatment was 7 days (IQR = 5–11 days). The present study shows that ¾ of the patients were profoundly immunocompromised and had been diagnosed for HIV within the past year. Antifungal treatment was often initiated presumptively on admission. Over time there was a significant gradual decline in early death.

Mortality trends and causes of death among HIV positive patients at Newlands Clinic in Harare, Zimbabwe

Background

We report trends in mortality patterns and causes among HIV positive patients, who initiated antiretroviral therapy (ART), at an urban clinic in Harare, Zimbabwe.

Methods

A retrospective cohort study was conducted in which routinely collected data for patients enrolled and followed up between February 2004 and December 2017 were assessed. Patients follow up was from the day of the treatment initiation until exit by death, transfer out or loss to follow up. Two doctors categorized causes of death (COD) as tuberculosis (TB), communicable AIDS, non-communicable diseases (NCDs), malignancies, others and unknown. We used competing risk survival analysis, first to estimate all-causes and cause-specific mortality rates over time, and then to assess risk factors of different causes of death.

Results

A total of 4 868 patients were followed up for 27 527 person years (PY). Among the 506 patients who died, COD was unknown for 76 patients (15%) and common COD were TB (n = 71, 14%), Malignancies (n = 54, 10.7%) Meningitis (n = 39, 7.7%) and NCDs (n = 60, 11.9%). 49.4% of the deaths were within the first year of starting ART. Median age at death was 36 years (IQR:19–46). There was a near threefold increase in proportion of deaths due to NCDs and malignancies over the period of follow up. Low baseline CD4 cell count and WHO stages 3 & 4 were significant risk factors for all-cause mortality.

Conclusions

TB remains the leading cause of death among HIV infected people. Deaths due to NCDs and malignancies increased over time. ART facilities need to incorporate management of NCDs including cancer as part of comprehensive care of PLHIV to reduce mortality.

Evaluation of a Novel Semiquantitative Cryptococcal Antigen Lateral Flow Assay in Patients with Advanced HIV Disease

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores.

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores. A total of 872 plasma samples were tested using both the CrAgSQ LFA and the conventional IMMY CrAg LFA, of which 692 were sequential samples from HIV-positive individuals undergoing CrAg screening and an additional 180 were known CrAg-positive plasma samples archived from prior studies. Interrater agreement in CrAgSQ reading was excellent (98.17% agreement, Cohen’s kappa 0.962, P < 0.001). Using the IMMY CrAg LFA as a reference standard, CrAgSQ was 93.0% sensitive (95% confidence interval [CI] 80.9% to 98.5%) and 93.8% specific (95% CI, 91.7% to 95.6%). After reclassification of discordant results using CrAg enzyme immunoassay testing, the sensitivity was 98.1% (95% CI, 90.1% to 100%) and specificity 95.8% (95% CI, 93.9% to 97.2%). The median CrAg titers for semiquantitative score categories (1+ to 4+) were 1:10 (interquartile range [IQR], 1:5 to 1:20) in the CrAgSQ 1+ category, 1:40 (IQR, 1:20 to 1:80) in the CrAgSQ 2+ category, 1:640 (IQR, 1:160 to 1:2,560) in the CrAgSQ 3+ category, and 1:5,120 (IQR, 1:2,560 to 1:30,720) in the CrAgSQ 4+ category. Increasing CrAgSQ scores were strongly associated with 10-week mortality. The IMMY CrAgSQ test had high sensitivity and specificity compared to the results for the IMMY CrAg LFA and provided CrAg scores that were associated with both conventional CrAg titers and clinical outcomes.

Prevalence of cryptococcal antigen (CrAg) among HIV-positive patients in Eswatini, 2014-2015

BACKGROUND

Cryptococcal meningitis is a leading cause of death amongst people living with HIV. However, routine cryptococcal antigen (CrAg) screening was not in the national guidelines in Eswatini.

OBJECTIVES

A cross-sectional study was conducted between August 2014 and March 2015 to examine CrAg prevalence at Mbabane Government Hospital in Eswatini.

METHODS

We collected urine and whole blood from antiretroviral-therapy-naïve patients with HIV and a cluster of differentiation 4 (CD4) counts < 200 cells/mm3 for plasma and urine CrAg lateral flow assay (LFA) screening at the national HIV reference laboratory. Two CD4 cut-off points were used to estimate CrAg prevalence: CD4 < 100 and < 200 cells/mm3. Sensitivity and specificity of urine CrAg LFA was compared to plasma CrAg LFA.

RESULTS

Plasma CrAg prevalence was 4% (8/182, 95% confidence interval [CI]: 2-8) amongst patients with CD4 counts of < 200 cells/mm3, and 8% (8/102, 95% CI: 3-15) amongst patients with CD4 counts of < 100 cells/mm3. Urine CrAg LFA had a sensitivity of 100% (95% CI: 59-100) and a specificity of 80% (95% CI: 72-86) compared with plasma CrAg LFA tests for patients with CD4 < 200 cells/mm3. Forty-three per cent of 99 patients with CD4 < 100 were at World Health Organization clinical stages I or II.

CONCLUSION

The prevalence of CrAg in Eswatini was higher than the current global estimate of 6% amongst HIV-positive people with CD4 < 100 cell/mm3, indicating the importance of initiating a national screening programme. Mechanisms for CrAg testing, training, reporting, and drug and commodity supply issues are important considerations before national implementation.

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.

Cryptococcal antigenemia and its predictors among HIV infected patients in resource limited settings: a systematic review

Background

Cryptococcosis is an opportunistic fungal infection that primarily affects people with advanced HIV/AIDS and is an important cause of morbidity and mortality around the globe. By far the most common presentation of the disease is cryptococcal meningitis (CM), which leads to an estimated 15–20% of all HIV related deaths worldwide, 75% of which are in sub-Saharan Africa. However, to the best of our knowledge there is quite limited reviewed data on the epidemiology of cryptococcal antigenemia in a large HIV-infected population in resource limited settings.

Methods

Articles published in English irrespective of the time of publication were systematically searched using comprehensive search strings from PubMed/Medline and SCOPUS. In addition, Google Scholar and Google databases were searched manually for grey literature. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. The pooled prevalence of cryptococcal antigenemia was determined with 95% confidence interval (CI).

Results

Among 2941 potential citations, we have included 22 studies with a total of 8338 HIV positive individuals. The studies were reported in ten different countries during the year (2007–2018). Most of the articles reported the mean CD4 count of the participants below 100 cells/μl. The pooled prevalence of cryptococcal antigenemia at different CD4 count and ART status was at 8% (95%CI: 6–10%) (ranged between 1.7 and 33%). Body mass index (BMI) < 18.5 kg/m², CD4 count < 100 cells, patients presenting with headache and male gender were reported by two or more articles as an important predictors of cryptococcal antigenemia.

Conclusions

Implementing a targeted screening of HIV patients with low BMI, CD4 count < 100 cells, having headache and males; and treatment for asymptomatic cryptococcal disease should be considered. Additional data is needed to better define the epidemiology of cryptococcal antigenemia and its predictors in resource limited settings in order to optimize the prevention, diagnosis, and treatment strategies.

Current burden of serious fungal infections in Republic of Congo

BACKGROUND

The Republic of Congo (RoC) is characterised by a high prevalence of tuberculosis and HIV/AIDS, which largely drive the epidemiology of serious fungal infections.

OBJECTIVE

We aimed to estimate the current burden of serious fungal infections in RoC.

MATERIAL AND METHODS

Using local, regional or global data and estimates of population and at-risk population groups, deterministic modelling was employed to estimate national incidence or prevalence of the most serious fungal infections.

RESULTS

Our study revealed that about 5.4% of the Congolese population (283 450) suffer from serious fungal infections yearly. The incidence of cryptococcal meningitis, Pneumocystis jirovecii pneumonia and disseminated histoplasmosis in AIDS patients was estimated at 560, 830 and 120 cases per year. Oral and oesophageal candidiasis collectively affects 12 320 HIV-infected patients. Chronic pulmonary aspergillosis, 67% post-tuberculosis, probably has a prevalence of 3420. Fungal asthma (allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation) probably has a prevalence of 3640 and 4800, although some overlap due to disease definition is likely. The estimated prevalence of recurrent vulvovaginal candidiasis and tinea capitis is 85 440 and 178 400 respectively. Mostly related to agricultural activity, fungal keratitis affects an estimated 700 Congolese yearly.

CONCLUSION

These data underline the urgent need for an intensified awareness towards Congolese physicians to fungal infections and for increased efforts to improve diagnosis and management of fungal infections in the RoC.

Presentation and outcome of suspected sepsis in a high-HIV burden, high antiretroviral coverage setting

Objective:

To define sepsis syndromes in high-HIV burden settings in the antiretroviral therapy (ART) era. Methods: We characterized a prospective cohort of adults presenting to a tertiary emergency department in Harare, Zimbabwe with suspected community-acquired sepsis using blood and urine cultures, urine tuberculosis lipoarabinomannan (TB LAM), and serum cryptococcal antigen (CrAg) testing. The primary outcome was 30-day all-cause mortality.

Results:

Of 142 patients enrolled 68% (n = 96/142, 95% confidence interval (CI) [60–75%]) were HIV-positive, 41% (n = 39/96, 95% CI [31–50%]) of whom were ART-naïve. Among HIV-positive patients, both opportunistic pathogens (TB LAM-positivity, 36%, 95% CI [24–48%]; CrAg-positivity, 15%, 95% CI [7–23%]) and severe non-AIDS infections (S. pneumoniae urine antigen-positivity 12%, 95% CI [4–20%]; bacteraemia 17% (n = 16/96, 95% CI [9–24%]), of which 56% (n = 9/16, 95% CI [30–80%]) were gram-negative organisms) were common. Klebsiella pneumoniae recovered from blood and urine was uniformly resistant to ceftriaxone, as were most Escherichia coli isolates. Acknowledging the power limitations of our study, we conclude that relative to HIV-negative patients, HIV-positive patients had modestly higher 30-day mortality (adjusted hazard ratio (HR) 1.88, 95% CI [0.78–4.55]; p = 0.16, and 3.59, 95% CI [1.27–10.16], p = 0.02) among those with and without viral suppression, respectively.

Conclusion:

Rapid point-of-care assays provide substantial clinically actionable information in the setting of suspected sepsis, even in areas with high ART coverage. Antimicrobial resistance to first-line antibiotics in high burden settings is a growing 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).

Cost-effectiveness of reflex laboratory-based cryptococcal antigen screening for the prevention and treatment of cryptococcal meningitis in Botswana

Background: Cryptococcal antigen (CrAg) screening for antiretroviral therapy (ART)-naïve adults with advanced HIV/AIDS can reduce the incidence of cryptococcal meningitis (CM) and all-cause mortality. We modeled the cost-effectiveness of laboratory-based "reflex" CrAg screening for ART-naïve CrAg-positive patients with CD4<100 cells/µL (those currently targeted in guidelines) and ART-experienced CrAg-positive patients with CD4<100 cells/µL (who make up an increasingly large proportion of individuals with advanced HIV/AIDS). Methods: A decision analytic model was developed to evaluate CrAg screening and treatment based on local CD4 count and CrAg prevalence data, and realistic assumptions regarding programmatic implementation of the CrAg screening intervention. We modeled the number of CrAg tests performed, the number of CrAg positives stratified by prior ART experience, the proportion of patients started on pre-emptive antifungal treatment, and the number of incident CM cases and CM-related deaths. Screening and treatment costs were evaluated, and cost per death or disability-adjusted life year (DALY) averted estimated. Results: We estimated that of 650,000 samples undergoing CD4 testing annually in Botswana, 16,364 would have a CD4<100 cells/µL and receive a CrAg test, with 70% of patients ART-experienced at the time of screening. Under base model assumptions, CrAg screening and pre-emptive treatment restricted to ART-naïve patients with a CD4<100 cells/µL prevented 20% (39/196) of CM-related deaths in patients undergoing CD4 testing at a cost of US$2 per DALY averted. Expansion of preemptive treatment to include ART-experienced patients with a CD4<100 cells/µL resulted in 55 additional deaths averted (a total of 48% [94/196]) and was cost-saving compared to no screening. Findings were robust across a range of model assumptions. Conclusions: Reflex laboratory-based CrAg screening for patients with CD4<100 cells/µL is a cost-effective strategy in Botswana, even in the context of a relatively low proportion of advanced HIV/AIDS in the overall HIV-infected population, the majority of whom are ART-experienced.

Evaluation of low cryptococcal antigen titer as determined by the lateral flow assay in serum and cerebrospinal fluid among HIV-negative patients: a retrospective diagnostic accuracy study

Cryptococcosis is one of the most common opportunistic infections in both immunocompetent and immunocompromised hosts. Although the cryptococcal antigen (CrAg) lateral flow assay (LFA) has been widely used in clinical settings due to its high sensitivity and specificity, the diagnostic value of a low CrAg LFA titers remains unclear. In this study, we performed a retrospective analysis of 149 HIV-negative patients with low CrAg LFA titers (≤1:10) in a Chinese tertiary hospital from January 2013 to December 2017, to evaluate the diagnostic value of low CrAg LFA titers in serum and cerebrospinal fluid (CSF) at different thresholds. Sensitivity and specificity of low CrAg LFA titers in patients with definitive diagnoses of cryptococcosis were 39.6% (95% CI, 29.7–50.1%) and 100% (95% CI, 69.2–100%), respectively, at a threshold of 1:10 in serum. A sensitivity of 72.9% (95% CI, 62.9–81.5%) and a decreased specificity of 70.0% (95% CI, 34.8–93.3%) were observed at a threshold of 1:5 in serum. No false-positive cases were identified in patients with low CrAg titers in CSF and all positive predictive values (PPVs) were 100%. Among the cases with low serum CrAg titers, lumbar puncture was performed in 97 patients and positive CSF CrAg titers were reported in 6 patients. In conclusion, the results of this study imply that low CrAg LFA titer, either in serum or CSF, is crucial for early diagnosis of cryptococcosis in HIV-negative patients, and lumbar puncture is recommended to be performed routinely for CSF testing when a positive low serum titer is reported. Cryptococcal meningitis should be considered seriously when the CSF CrAg titer is positive.

Serum Cryptococcal Antigen Testing in Immunosuppressed HIV-positive Children and Adolescents

OBJECTIVES

Describe the epidemiology of immunocompromised HIV-infected pediatric (children and adolescents ≤ 19 years) and adults (> 19 years) with positive serum cryptococcal antigen lateral flow assay (CrAg-LFA) in KwaZulu-Natal.

DESIGN

Retrospective review of laboratory-based database and clinical charts.

METHODS

A review of the National Health Laboratory Services database of all serum CrAg-LFA performed in KwaZulu-Natal between June 2015 and December 2016 and comparison of the epidemiology of pediatric and adult patients was conducted. A reflex serum CrAg-LFA (IMMY CrAg-LFA) was performed on samples with CD4 counts < 100 cells/μL. Charts of all pediatric patients with a positive CrAg-LFA at Prince Mshiyeni Memorial Hospital were reviewed and 1-year outcome assessed.

RESULTS

A total of 22,741 laboratory records were retrieved, and 1140 records were removed because of duplicate entries (1074) and insufficient data (64). There was a statistically significant difference in the incidence of positive CrAg-LFA in pediatrics and adults, respectively [40 (3.5%) versus 1194 (5.8%), P = 0.001]. The incidence of positive CrAg-LFA in Ethekwini district was 59 and 56 cases per 100,000 persons in adolescents 10-14 years and 15-19 years, respectively. Six of the 8 patients with available treatment history were on antiretroviral treatment (ART) with immune failure at the time of CrAg-LFA testing.

CONCLUSIONS

Severe immune suppression in adolescents on ART is a risk factor for cryptococcal antigenemia. A concerted effort to timeously manage ART failure in adolescents with appropriate changing of ART regimens is urgently warranted.

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.

Clinical Significance of Low Serum Cryptococcal Antigen Titers by Lateral Flow Assay in Immunocompromised Patients: a Retrospective Case-Control Study

Cryptococcus species are associated with invasive fungal infections in immunosuppressed individuals. The clinical significance of low-titer cryptococcal antigen (CrAg) by lateral flow assay is frequently uncertain. We investigated the correlation of low CrAg titers with disease in an immunocompromised patient population. Patients with first-time positive CrAg results with low serum titers (≤1:10) at two medical centers (Los Angeles, CA) from April 2014 to July 2018 were included. Age-matched controls with high (≥1:20) and negative titers were selected. We extracted medical records for pertinent clinical, radiologic, and laboratory data for cryptococcal disease. From 2,196 serum samples submitted for CrAg testing, 96 cases were included (32 each in low-titer, high-titer, and negative-titer groups). One or more immunocompromising condition was identified in 95% of patients, including HIV infection (45%), solid organ transplant (26%), and cirrhosis (22%). Pulmonary cryptococcosis was diagnosed in 9 (28%) low-titer and 8 (25%) high-titer patients (P = 1.00). Disseminated cryptococcosis occurred in 7 (22%) low-titer and 15 (47%) high-titers cases (P = 0.064). Titers ≤1:10 more frequently represented isolated antigenemia in HIV-positive than non-HIV, immunocompromised patients (P < 0.001). Follow-up testing in patients with ≤1:5 titers (n = 21) showed persistently low titers in 6 of 12 instances and increased titers in 2 cases. Twenty-seven patients with low CrAg titers were treated with antifungal therapy and 22 (81%) responded well clinically. Low-serum CrAg titers (≤1:10) correlated with cryptococcal disease in a substantial proportion of non-HIV immunocompromised patients and should prompt careful clinical workup for cryptococcal infection.