Cryptococcal antigen screening and early antifungal treatment to prevent cryptococcal meningitis: a review of the literature

Prevalence, treatment, and factors associated with cryptococcal meningitis post introduction of integrase inhibitors antiretroviral based regimens among People Living with HIV in Tanzania

OBJECTIVE

This study aimed to assess the prevalence of Cryptococcal Meningitis (CM), treatment practice, and the associated factors post-introduction of Tenofovir Lamivudine and Dolutegravir (TLD) regimen among People Living with HIV (PLHIV) in Tanzania.

METHODS

This was an analytical cross-sectional study, and the data was collected retrospectively in three public regional referral hospitals (RRHs) in Dar es Salaam, Tanzania. A total of 405 files of the PLHIV admitted in the medical wards on the TLD regimen from January 2019 to December 2022 were reviewed. The collected information includes the patient's demographic characteristics, Cryptococcal status, CD4 level at the time of CM diagnosis, status of using ART, CM treatment approach, and outcome. Data was analyzed using SPSS software version 23.

RESULTS

Out of 405 patients, the majority 267(65.9%) were female, 224(55.3%) were aged between 36-55 years, and 293(72.3%) were married. ART defaulters were found to be 37(9.1%). The prevalence of CM was found to be 48(11.9%), out of which 42(87.5%) received fluconazole alone. ART defaulter and marital status significantly (p-value < 0.05) were associated with those who tested CM positive.

CONCLUSION

The study found the prevalence of CM among PLHIV to be significantly high and the majority were treated with fluconazole alone. ART defaulters and marital status were significantly associated with one being CM positive. Responsible authorities and stakeholders should enforce guideline adherence and PLHIV should be encouraged on medication adherence.

Preemptive Therapy in Cryptococcosis Adjusted for Outcomes

Cryptococcosis is one of the most serious opportunistic diseases in patients living with HIV. For this reason, early diagnosis and appropriate treatment are important.

OBJECTIVES

The aim of the study was to understand the development of patients diagnosed with cryptococcosis by detection of Cryptococcus antigen in serum by lateral flow assay (CrAg LFA) without nervous system involvement and with treatment in accordance with the results.

MATERIALS AND METHODS

A retrospective, longitudinal, analytical study was performed. Seventy patients with cryptococcosis initially diagnosed by serum CrAg LFA without meningeal involvement between January 2019 and April 2022 were analyzed for medical records. The treatment regimen was adapted to the results of blood culture, respiratory material, and pulmonary tomography imaging.

RESULTS

Seventy patients were included, 13 had probable pulmonary cryptococcosis, 4 had proven pulmonary cryptococcosis, 3 had fungemia, and 50 had preemptive therapy without microbiological or imaging findings compatible with cryptococcosis. Among the 50 patients with preemptive therapy, none had meningeal involvement or cryptococcosis recurrences to date.

CONCLUSION

Preemptive therapy avoided progression to meningitis in CrAg LFA-positive patients. Preemptive therapy with dose adjustment of fluconazole in patients with the mentioned characteristics was useful despite the use of lower doses than recommended.

Challenges in Serologic Diagnostics of Neglected Human Systemic Mycoses: An Overview on Characterization of New Targets

Systemic mycoses have been viewed as neglected diseases and they are responsible for deaths and disabilities around the world. Rapid, low-cost, simple, highly-specific and sensitive diagnostic tests are critical components of patient care, disease control and active surveillance. However, the diagnosis of fungal infections represents a great challenge because of the decline in the expertise needed for identifying fungi, and a reduced number of instruments and assays specific to fungal identification. Unfortunately, time of diagnosis is one of the most important risk factors for mortality rates from many of the systemic mycoses. In addition, phenotypic and biochemical identification methods are often time-consuming, which has created an increasing demand for new methods of fungal identification. In this review, we discuss the current context of the diagnosis of the main systemic mycoses and propose alternative approaches for the identification of new targets for fungal pathogens, which can help in the development of new diagnostic tests.

Determinants of cryptococcal antigen (CrAg) screening uptake in Kampala, Uganda: An assessment of health center characteristics

Cryptococcal antigen (CrAg) screening and pre-emptive antifungal therapy for people with CD4 cell counts <100 cells/μl are recommended by the World Health Organization and several national HIV guidelines. We sought to evaluate CrAg screening program implementation across Uganda, in relation to health center level and distance from the capital. We conducted a cross-sectional study of 22 health centers across southern Uganda from April to June 2019. We reviewed laboratory records regarding number of CD4 cell count tests performed, proportion of outpatients with CD4 counts <200 cells/μl, and number of CrAg screening tests performed. We administered surveys to health center staff to understand barriers to advanced HIV care. We observed no significant difference in health center level and performance of CrAg screening; with each subsequent health center level, there was 1.17-fold (95% CI: 0.92-1.41) higher odds of CrAg screening performed per level. CrAg screening uptake was not associated with distance from the capital city (odds ratio = 0.96, 95% CI: 0.89-1.04). Qualitative data from surveys indicated that limitations to uptake of CrAg screening were secondary to dysfunctional CD4 machines, lack of provider awareness of CrAg screening guidelines, and inadequate/intermittent supply of CrAg tests. There were no significant associations between CrAg screening uptake and level of health center or distance of health center from the capital city. We identified systemic barriers to CrAg screening related to inadequate CD4 testing, insufficient knowledge regarding national screening guidelines, and irregular laboratory testing supplies.

LAY SUMMARY

The objective of this study was to evaluate cryptococcal antigen (CrAg) screening program implementation in Uganda, by type of healthcare center and by distance from the capital city. CrAg screening uptake was not associated with distance from the capital city, or the type of healthcare center.

Identification of Disease-Associated Cryptococcal Proteins Reactive With Serum IgG From Cryptococcal Meningitis Patients

Cryptococcus neoformans, an opportunistic fungal pathogen ubiquitously present in the environment, causes cryptococcal meningitis (CM) mainly in immunocompromised patients, such as AIDS patients. We aimed to identify disease-associated cryptococcal protein antigens targeted by the human humoral immune response. Therefore, we used sera from Colombian CM patients, with or without HIV infection, and from healthy individuals living in the same region. Serological analysis revealed increased titers of anti-cryptococcal IgG in HIV-negative CM patients, but not HIV-positive CM patients, compared to healthy controls. In contrast, titers of anti-cryptococcal IgM were not affected by CM. Furthermore, we detected pre-existing IgG and IgM antibodies even in sera from healthy individuals. The observed induction of anti-cryptococcal IgG but not IgM during CM was supported by analysis of sera from C. neoformans-infected mice. Stronger increase in IgG was found in wild type mice with high lung fungal burden compared to IL-4Rα-deficient mice showing low lung fungal burden. To identify the proteins targeted by human anti-cryptococcal IgG antibodies, we applied a quantitative 2D immunoproteome approach identifying cryptococcal protein spots preferentially recognized by sera from CM patients or healthy individuals followed by mass spectrometry analysis. Twenty-three cryptococcal proteins were recombinantly expressed and confirmed to be immunoreactive with human sera. Fourteen of them were newly described as immunoreactive proteins. Twelve proteins were classified as disease-associated antigens, based on significantly stronger immunoreactivity with sera from CM patients compared to healthy individuals. The proteins identified in our screen significantly expand the pool of cryptococcal proteins with potential for (i) development of novel anti-cryptococcal agents based on implications in cryptococcal virulence or survival, or (ii) development of an anti-cryptococcal vaccine, as several candidates lack homology to human proteins and are localized extracellularly. Furthermore, this study defines pre-existing anti-cryptococcal immunoreactivity in healthy individuals at a molecular level, identifying target antigens recognized by sera from healthy control persons.

Cryptococcosis

Cryptococcosis is an invasive fungal infection of global significance caused by yeasts of the genus Cryptococcus. The prevalence of HIV in certain areas of the world and the expanding population of immunocompromised patients contribute to the ongoing global disease burden. Point-of-care serologic testing has allowed for more rapid diagnosis and implementation of screening programs in resource-limited settings. Management involves therapy aimed at reduction in fungal burden, maintenance of intracranial pressure, and optimization of host immunity. Despite diagnostic and therapeutic advances, cryptococcosis continues to be a disease with unacceptably high incidence and mortality, particularly in resource-limited settings.

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.

Cryptococcus neoformans meningitis in kidney transplant recipients: A diagnostic and therapeutic challenge

Cryptococcosis is the third most common invasive fungal infection in solid organ transplant recipients. We describe three cases of neuro-meningeal cryptococcosis occurring among kidney transplant (KT) patients, and discuss the diagnostic and therapeutic challenges in this context. Median time from KT to infection was 6 months [range: 3-9]. The most common clinical manifestations at diagnosis were fever (2/3), headache (2/3), and confusion (2/3); none had extra-neurological involvement. CrAg was positive in all cases at diagnosis both in serum and cerebrospinal fluid (CSF). For two patients, analysis of previous samples showed that CrAg was detected in plasma up to 4 weeks before diagnosis. All patients received induction treatment with liposomal amphotericin-B (L-AmB) and flucytosine for a median duration of 10 days [range: 7-14], followed by fluconazole maintenance therapy. Acute kidney injury secondary to L-AmB therapy was observed in only one case, but all patients had a tacrolimus overdose following initiation of maintenance therapy due to drug-drug interactions between fluconazole and tacrolimus. Among KTR, early detection of Cryptococcus meningitis using serum CrAg is possible. Close monitoring of renal function during treatment is essential due to the nephrotoxicity of L-AmB, but also drug-drug interactions between fluconazole and calcineurin inhibitors.

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.

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.

Underlying Cryptococcal Diseases and the Correlation With Serum Cryptococcal Antigen Titers in Hospitalized HIV-Infected Patients Screened Positive for Cryptococcal Antigenemia

Background: The prevalence of different underlying cryptococcal diseases in human immunodeficiency virus (HIV)-infected patients screened positive for cryptococcal antigenemia and the association between cryptococcal diseases and serum cryptococcal antigen (CrAg) titers were understudied.

Methods: HIV-infected patients with CD4 < 200 cells/ul, admitted to the second hospital of Nanjing, Nanjing, China, from January 2016 to September 2019, were retrospectively analyzed. Integrated into routine HIV care, all these patients were screened for cryptococcal antigenemia with CrAg lateral flow assay. Positive patients received extensive laboratory and radiological studies to evaluate underlying cryptococcal diseases.

Results: A total of 872 HIV inpatients were screened for serum CrAg. The prevalence of cryptococcal antigenemia in the study population was 10.3% (95% CI, 8.3–12.3%), 87.6% of which with cryptococcal antigenemia had clinically cryptococcal diseases. The prevalence of cryptococcal meningitis (CM), cryptococcemia and pulmonary cryptococcosis (PC) in patients with cryptococcal antigenemia were 58.4% (95% CI, 48.0–68.9%), 50.7% (95% CI, 39.1–62.2%), and 68.5% (95% CI, 58.7–78.4%), respectively. The median (range) serum CrAg titers in severe cryptococcal diseases (CM or cryptococcemia), localized PC (without co-existing CM or cryptococcemia) and isolated cryptococcal antigenemia were 1:2560 (1:10–1:2560), 1:20 (1:2–1:320), and 1:5 (1:2–1:320), respectively. Serum CrAg titers ≥1:320 were independently associated with CM (adjusted OR 26.88; 95%CI, 8.36–86.42). Severe cryptococcal diseases were found in all patients with serum CrAg titers ≥1:640. None of the patients with serum CrAg titers ≤ 1:5 had CM.

Conclusion: The prevalence of cryptococcal antigenemia was high in HIV inpatients, supporting routine CrAg screening. Clinical cryptococcal diseases, most commonly the PC, existed in the majority of the patients with cryptococcal antigenemia. Since serum CrAg titer is correlated with cryptococcal disease severity, it may possibly guide anti-fungal treatment.

Diagnostic and management considerations in the modern patient with AIDS: a case of concurrent disseminated Kaposi sarcoma and colesional Cryptococcus neoformans

In the era of highly active antiretroviral therapy (HAART), disseminated Kaposi sarcoma (KS) has become much rarer in the USA. We report a case of a 34-year-old man with KS of the skin, oropharynx, lung and rectum. Within the same lung nodule, we discovered significant burden of colesional Cryptococcus neoformans, in the context of a positive asymptomatic cryptococcal antigenemia, which was a previously unreported occurrence. The gold standard of treatment for KS continues to be HAART. The role of chemotherapy is still controversial. In addition, a cryptococcal antigen screen-and-treat approach with fluconazole is still not routinely recommended in the USA to prevent serious meningeal disease despite recent studies showing efficacy and applicability. We discuss both issues here and the outcome of our patient. We also present the patient's own unique perspective in dealing with the ramifications of these diagnoses.

Unique subsite specificity and potential natural function of a chitosan deacetylase from the human pathogen Cryptococcus neoformans

Cryptococcus neoformans is an opportunistic fungal pathogen that infects ∼280,000 people every year, causing >180,000 deaths. The human immune system recognizes chitin as one of the major cell-wall components of invading fungi, but C. neoformans can circumvent this immunosurveillance mechanism by instead exposing chitosan, the partly or fully deacetylated form of chitin. The natural production of chitosans involves the sequential action of chitin synthases (CHSs) and chitin deacetylases (CDAs). C. neoformans expresses four putative CDAs, three of which have been confirmed as functional enzymes that act on chitin in the cell wall. The fourth (CnCda4/Fpd1) is a secreted enzyme with exceptional specificity for d-glucosamine at its -1 subsite, thus preferring chitosan over chitin as a substrate. We used site-specific mutagenesis to reduce the subsite specificity of CnCda4 by converting an atypical isoleucine residue in a flexible loop region to the bulkier or charged residues tyrosine, histidine, and glutamic acid. We also investigated the effect of CnCda4 deacetylation products on human peripheral blood-derived macrophages, leading to a model explaining the function of CnCda4 during infection. We propose that CnCda4 is used for the further deacetylation of chitosans already exposed on the C. neoformans cell wall (originally produced by CnChs3 and CnCda1 to 3) or released from the cell wall as elicitors by human chitinases, thus making the fungus less susceptible to host immunosurveillance. The absence of CnCda4 during infection could therefore promote the faster recognition and elimination of this pathogen.

Reduction of Human DNA Contamination in Clinical Cerebrospinal Fluid Specimens Improves the Sensitivity of Metagenomic Next-Generation Sequencing

Metagenomics next-generation sequencing (mNGS) is increasingly available for the detection of obscure infectious diseases of the central nervous system. However, human DNA contamination from elevated white cells, one of the characteristic cerebrospinal fluid (CSF) features in meningitis patients, greatly reduces the sensitivity of mNGS in the pathogen detection. Currently, effective approaches to selectively reduce host DNA contamination from clinical CSF samples are still lacking. In this study, a total of 20 meningitis patients were enrolled, including 10 definitively diagnosed tuberculous meningitis (TBM) and 10 definite cryptococcal meningitis (CM) cases. To evaluate the effect of reduced human DNA in the sensitivity of mNGS detection, three specimen-processing protocols were performed: (i) To remove human DNA, saponin, a nonionic surfactant, was used to selectively lyse white cells in CSF followed by DNase treatment prior to the extraction of DNA; (ii) to reduce host DNA, CSF was centrifuged to remove human cells, and the supernatant was collected for DNA extraction; and (iii) DNA extraction from the unprocessed specimens was set as the control. We found that saponin processing significantly elevated the NGS unique reads for Cryptococcus (P < 0.01) compared with the control but had no effects for Mycobacterium tuberculosis (P > 0.05). However, detection of centrifuged supernatants improved the NGS unique reads for both TBM and CM compared with controls (P < 0.01). Our results demonstrate that the use of mNGS of centrifuged supernatants from clinical CSF samples in patients with TBM and CM is a simple and effective method to improve the sensitivity of pathogen detection.

Cryptococcal Antigen Testing in an Integrated Medical System: Eastern Wisconsin

Cryptococcosis is a serious environmentally acquired endemic fungal infection commonly associated with immunocompromised hosts. Little is known regarding frequency or distribution in Wisconsin. We explored the geodemographic and clinical features of patients tested with cryptococcal antigen tests (CrAg) - previously shown to be >90% sensitive and >90% specific - within a large health care system located in eastern Wisconsin. To examine this, we retrospectively analyzed 1465 CrAg tests on 1211 unique patients (female: 50.2%; white race: 73.9%; mean age: 53.7 ± 16.5 years). At least one CrAg result was positive in 23 of 1211 patients (1.9%). From these, 21 of 23 were immunocompromised. Positive patients were disproportionately male (82.6%) and nonwhite (3.8% of those tested vs 1.2% of whites tested); P<0.01 for both. These associations remained in multivariable models. Positive patients were not significantly older (59.1 vs 53.6 years; P=0.07). Overall, 17 separate zip codes had at least one positive case. Positive patients were more prevalent in the zip codes that included the city of Milwaukee (11 of 377 [2.9% of those tested] vs 12 of 834 [1.4% of all those tested in the remaining area of the state]), but this difference was not statistically significant. No other case clustering or close proximity to waterways was observed (41% were <162 m from green space, similar to historical controls). Overall, male sex, nonwhite race/ethnicity, and immunocompromised status, not zip code, were statistically associated with positive CrAg.

Prospective cohort of AIDS patients screened for cryptococcal antigenaemia, pre-emptively treated and followed in Brazil

Background

Cryptococcal meningitis has a high morbidity and mortality among AIDS population. Cryptococcal antigen (CrAg) detection is considered an independent predictor for meningitis and death. Since 2011, the World Health Organization recommends CrAg screening for people living with HIV/AIDS (PLHAs) with CD4 counts <100–200 cells/μl. Its implementation is still limited in low-middle-income countries. We aimed to estimate the prevalence and predictors of CrAg positivity in PLHAs. We also evaluated outcomes among those who were CrAg-positive.

Methods

Prospective cohort conducted at an infectious diseases hospital, in Brazil. Adults with CD4 <200 cells/μl, without previous cryptococcal disease and regardless of symptoms, were enrolled from 2015 to 2018. CrAg tests were performed by LFA. Lumbar puncture was done in CrAg+ individuals and pre-emptive therapy was offered for those without meningitis.

Results

Of 214 individuals recruited, 88% were antiretroviral experienced, of which only 11.6% with viral suppression. Overall, CrAg prevalence was 7.9% (95% CI, 4.7–12.4). In CD4 ≤100 cells/μl group it was 7.5% (95% CI, 4.1–12.6) and 9.1% (95% CI, 3.4–19.0) in the group with CD4 101 to 199 cells/μl (p = 0.17). Prevalence in asymptomatic subjects was 5.3% (95% CI, 1.4–13.1). One among 17 CrAg+ participants had documented meningoencephalitis and no subclinical meningitis was detected. Adherence to pre-emptive treatment was 68.7% (11/16). There were no statistically significant differences in sociodemographic, clinical or laboratory characteristics to predict CrAg positivity. No case of cryptococcal disease was diagnosed among CrAg + subjects, followed by a median of 12 months.

Conclusions

CrAg screening for severely immunosuppressed PLHAs in Brazil yielded a prevalence of 7.9%. No difference was found in the prevalence of CrAg stratified by CD4 values (CD4 <100 versus CD4 101–199 cells/μl). No clinical nor laboratory factors predicted CrAg positivity, corroborating the need for the implementation of universal CrAg screening for PLHAs with CD4 <200 cells/μl in similar settings.

Lessons learned: Retrospective assessment of outcomes and management of patients with advanced HIV disease in a semi-urban polyclinic in Epworth, Zimbabwe

INTRODUCTION

HIV continues to be one of the leading causes of infectious death worldwide and presentation with advanced HIV disease is associated with increased morbidity and mortality. Recommendations for the management of advanced HIV disease include prompt screening and treatment of opportunistic infections, rapid initiation of ART and intensified adherence support. We present treatment outcomes of a cohort of patients presenting with advanced HIV disease in a semi-urban Zimbabwean polyclinic.

METHODS

Retrospective cohort analysis of adult patients enrolled for care at Epworth polyclinic, Zimbabwe between 2007 and end June 2016. Treatment outcomes at 6 and 12 months were recorded. Multivariate logistical regression analysis was undertaken to identify risk factors for presentation with advanced HIV Disease (CD4 count less than 200 cells/mm3 or WHO stage 3 or 4) and risks for attrition at 12 months.

RESULTS

16,007 anti-retroviral therapy naive adult patients were included in the final analysis, 47.4% of whom presented with advanced HIV disease. Patients presenting with advanced HIV disease had a higher mortality rate at 12 months following enrollment compared to early stage patients (5.11% vs 0.45%). Introduction of a package of differentiated care for patients with a CD4 count of less than 100 cells/mm3 resulted in diagnosis of cryptococcal antigenaemia in 7% of patients and a significant increase in the diagnosis of TB, although there was no significant difference in attrition at 6 or 12 months for these patients compared to those enrolled prior to the introduction of the differentiated care.

CONCLUSIONS

The burden of advanced HIV disease remained high over the study period in this semi-urban polyclinic in Zimbabwe. Introduction of a package of differentiated care for those with advanced HIV disease increased the diagnosis of opportunistic infections and represents a model of care which can be replicated in other polyclinics in the resource constrained Zimbabwean context.

Prevalence, predictors, and management of advanced HIV disease among individuals initiating ART in Senegal, West Africa

BACKGROUND

The WHO guidelines for the management of advanced HIV disease recommend a package of care consisting of rapid initiation of antiretroviral therapy (ART), enhanced screening and diagnosis of tuberculosis (TB) and cryptococcal meningitis, co-trimoxazole prophylaxis, isoniazid preventive therapy (IPT), fluconazole pre-emptive therapy, and adherence support. The goals of this study were to determine the prevalence of advanced HIV disease among individuals initiating ART in Senegal, to identify predictors of advanced disease, and to evaluate adherence to the WHO guidelines.

METHODS

This study was conducted among HIV-positive individuals initiating ART in Dakar and Ziguinchor, Senegal. Clinical evaluations, laboratory analyses, questionnaires and chart review were conducted. Logistic regression was used to identify predictors of advanced disease.

RESULTS

A total of 198 subjects were enrolled; 70% were female. The majority of subjects (71%) had advanced HIV disease, defined by the WHO as a CD4 count < 200 cells/mm³ or clinical stage 3 or 4. The median CD4 count was 185 cells/mm³. The strongest predictors of advanced disease were age ≥ 35 (OR 5.80, 95%CI 2.35-14.30) and having sought care from a traditional healer (OR 3.86, 95%CI 1.17-12.78). Approximately one third of subjects initiated ART within 7 days of diagnosis. Co-trimoxazole prophylaxis was provided to 65% of subjects with CD4 counts ≤350 cells/mm³ or stage 3 or 4 disease. TB symptom screening was available for 166 subjects; 54% reported TB symptoms. Among those with TB symptoms, 39% underwent diagnostic evaluation. Among those eligible for IPT, one subject received isoniazid. No subjects underwent CrAg screening or received fluconazole to prevent cryptococcal meningitis.

CONCLUSIONS

This is the first study to report an association between seeking care from a traditional healer and presentation with WHO defined advanced disease in sub-Saharan Africa. Given the widespread use of traditional healers in sub-Saharan Africa, future studies to further explore this finding are indicated. Although the majority of individuals in this study presented with advanced disease and warranted management according to WHO guidelines, there were numerous missed opportunities to prevent HIV-associated morbidity and mortality. Programmatic evaluation is needed to identify barriers to implementation of the WHO guidelines and enhanced funding for operational research is indicated.

Cryptococcal antigenemia and associated risk factors among ART-naïve and ART-experienced HIV-infected peoples at selected health institutions of Mekelle, Northern Ethiopia

Cryptococcal infection is a major cause of opportunistic infection in HIV/AID‐infected peoples. We determined cryptococcal antigenemia and cryptococcal meningitis among antiretroviral therapy (ART) initiated and ART‐naive HIV‐infected peoples. A cross‐sectional study was conducted at selected health facilities in Mekelle, Ethiopia. Blood was collected to determine CD4 and plasma cryptococcal antigen (CrAg). CSF CrAg and CSF culture and urease tests were also done. Socio‐demographic and clinical data were collected using a structured questionnaire and clinical chart review. From the enrolled study participants, 267 study participants had complete data, of which, 137 (51%) were females. From the study participants, 140 (52%) and 127 (48%) were ART experienced and ART naïve, respectively. The prevalence of cryptococcal antigenemia was 9 (3.4%). All the study participants, except one (CD4 = 120 cells/mm³), had CD4 count less than 100 cells/mm³. From CrAg‐positive peoples, 6 (4.7%) were ART naïve. Five CrAg‐positive peoples had cryptococcal meningitis. Being male, rural residence, and being hospitalized were associated with cryptococcal antigenemia. Cryptococcal infection poses a substantial risk of HIV‐positive peoples. This study provides relevant data for CrAg screening interventions in patients with low CD4 cell counts.

Detrimental Outcomes of Unmasking Cryptococcal Meningitis With Recent ART Initiation

BACKGROUND

Increased antiretroviral therapy (ART) availability has been associated with more patients developing cryptococcosis after ART initiation. Despite this changing epidemiology, data regarding cryptococcal meningitis in those already receiving ART are limited. We compared clinical presentations and outcomes among ART-naïve and ART-experienced Ugandans.

METHODS

We prospectively enrolled 605 HIV-infected persons with first-episode cryptococcal meningitis from August 2013 to May 2017 who received amphotericin-based combination therapy. We classified participants by ART status and ART duration and compared groups for 2-week survival.

RESULTS

Overall, 46% (281/605) of participants were receiving ART at presentation. Compared with those not receiving ART, those receiving ART had higher CD4 counts (P < .001) and lower cerebrospinal fluid fungal burdens (P < .001). Of those receiving ART, 56% (156/281) initiated ART within 6 months, and 18% (51/281) initiated ART within 14 days. Two-week mortality did not differ by ART status (27% in both ART-naïve and ART-experienced%; P > .99). However, 47% (24/51) of those receiving ART for ≤14 days died within 2 weeks, compared with 19% (20/105) of those receiving ART for 15-182 days and 26% (32/125) of those receiving ART for >6 months (P < .001). Among persons receiving ART for >6 months, 87% had HIV viral loads >1000 copies/mL.

CONCLUSIONS

Cryptococcosis after ART initiation is common in Africa. Patients initiating ART who unmask cryptococcal meningitis are at a high risk of death. Immune recovery in the setting of central nervous system infection is detrimental, and management of this population requires further study. Implementing pre-ART cryptococcal antigen screening is urgently needed to prevent cryptococcal meningitis after ART initiation.

The war on cryptococcosis: A Review of the antifungal arsenal

Cryptococcal meningitis is the most common central nervous system infection in the world today. It occurs primarily, but not exclusively, in immunocompromised individuals and despite substantial improvement in management of clinical events like AIDS, the numbers of cases of cryptococcosis remain very high. Unfortunately, despite several antifungal agents available for treatment, morbidity and mortality rates remain high with this fungal infection. In this Review, we will describe the treatments and strategies for success, identify the failures, and provide insights into the future developments / improvements for management. This sugar-coated yeast can play havoc within the human brain. Our goals must be to either prevent or diagnose disease early and treat aggressively with all our clinical tools when disease is detected.

Increased mortality among HIV infected patients with cryptococcal antigenemia in Guinea-Bissau

Cryptococcal antigenemia may precede development of cryptococcal meningitis and death among patients with advanced HIV infection. Among 200 retrospectively and randomly selected ART-naïve patients with CD4 counts < 100 cells/μl from Guinea-Bissau, 20 (10%) had a positive cryptococcal antigen test. Self-reported headache and fever were predictors of a positive test, while cryptococcal antigenemia was a strong predictor of death within the first year of follow-up, MRR 2.22 (95% CI: 1.15-4.30). Screening for cryptococcal antigenemia should be implemented for patients with advanced HIV in Guinea-Bissau. Pre-emptive anti-fungal therapy should be initiated prior to ART-initiation if the screening is positive.

Cryptococcal meningitis in AIDS

Cryptococcal meningitis remains a significant cause of morbidity and mortality amongst patients living with human immunodeficiency virus (HIV). The prevalence in the developed world has decreased as HIV is being diagnosed earlier, but is still significant, and the prevalence in resource-limited settings is exceedingly high. The presenting symptoms usually include a headache, fever, and, less often, cranial nerve abnormalities. Space-occupying lesions do occur, but are rare. Once diagnosed, patients should be treated with a combination of amphotericin and flucytosine, with step-down therapy to fluconazole for a minimum of a year, or until the CD4 count is above 100 cells/μL, whichever is longer. In the acute phase of treatment increased opening pressure is common, which should be managed aggressively with frequent lumbar punctures, or through neurosurgical interventions (lumbar drains, ventriculoperitoneal shunts) if those fail. Antiretrovirals should be delayed at least 2 weeks, but maybe as many as 10 weeks, after initiation of antifungal therapy in order to prevent clinical or subclinical immune reconstitution inflammatory syndrome (IRIS), which may lead to increased mortality. However, if IRIS does develop, there is no role for antiretroviral interruption, and the condition should be managed supportively by use of anti-inflammatories and aggressive management of elevated opening pressure, if present. Steroids should be administered for specific indications only (IRIS or cryptococcoma with cerebral edema and risk of herniation) as routine use of steroids increases mortality in cryptococcal meningitis.

Evaluation of a Cryptococcal antigen Lateral Flow Assay in serum and cerebrospinal fluid for rapid diagnosis of cryptococcosis in Colombia

A Lateral Flow Assay to detect cryptococcal antigen (CrAg^® LFA) in serum and cerebrospinal fluid for the rapid diagnosis of cryptococcosis was evaluated. A retrospective validation was performed. Sensitivity and specificity of the CrAg^® LFA was 100%. High concordance (kappa index=1.0) between Cryptococcal Antigen Latex Agglutination System (CALAS^®) and CrAg^® LFA was observed. CrAg^® LFA showed higher analytical sensitivity for detecting low concentrations of cryptococcal antigen.

Cryptococcal antigen screening by lay cadres using a rapid test at the point of care: A feasibility study in rural Lesotho

INTRODUCTION

Cryptococcal meningitis is one of the leading causes of death among people with HIV in Africa, primarily due to delayed presentation, poor availability and high cost of treatment. Routine cryptococcal antigen (CrAg) screening of patients with a CD4 count less than 100 cells/mm3, followed by pre-emptive therapy if positive, might reduce mortality in high prevalence settings. Using the cryptococcal antigen (CrAg) lateral flow assay (LFA), screening is possible at the point of care (POC). However, critical shortages of health staff may limit adoption. This study investigates the feasibility of lay counsellors conducting CrAg LFA screening in rural primary care clinics in Lesotho.

METHODS

From May 2014 to June 2015, individuals who tested positive for HIV were tested for CD4 count and those with CD4 <100 cells/mm3 were screened with CrAg LFA. All tests were performed by lay counsellors. CrAg-positive asymptomatic patients received fluconazole, while symptomatic patients were referred to hospital. Lay counsellors were trained and supervised by a laboratory technician and counsellor activity supervisor. Additionally, nurses and doctors were trained on CrAg screening and appropriate treatment.

RESULTS

During the study period, 1,388 people were newly diagnosed with HIV, of whom 129 (9%) presented with a CD4 count <100 cells/mm3. Of these, 128 (99%) were screened with CrAg LFA and 14/128 (11%) tested positive. Twelve of the 14 (86%) were asymptomatic, and received outpatient fluconazole. All commenced ART with a median time to initiation of 15.5 days [IQR: 14-22]. Of the asymptomatic patients, nine (75%) remained asymptomatic after a median time of 5 months [IQR; 3-6] of follow up. One (8%) became co-infected with tuberculosis and died and two were transferred out. The two patients with symptomatic cryptococcal meningitis (CM) were referred to hospital, where they later died.

CONCLUSIONS

CrAg LFA screening by lay counsellors followed by pre-emptive fluconazole treatment for asymptomatic cases, or referral to hospital for symptomatic cases, proved feasible. However, regular follow-up to ensure proper management of cryptococcal disease was needed. These early results support the wider use of CrAg LFA screening in remote primary care settings where upper cadres of healthcare staff may be in short supply.

Recent advances in AIDS-related cryptococcal meningitis treatment with an emphasis on resource limited settings

INTRODUCTION

Recent advances in the treatment and prevention of cryptococcal meningitis have the potential to decrease AIDS-related deaths. Areas covered: Targeted screening for asymptomatic cryptococcal antigenemia in persons with AIDS is a cost effective method for reducing early mortality in patients on antiretroviral therapy. For persons with symptomatic cryptococcal meningitis, optimal initial management with amphotericin and flucytosine improves survival compared to alternative therapies; however, amphotsericin is difficult to administer and flucytosine has not been available in middle or low income countries, where cryptococcal meningitis is most prevalent. Expert commentary: Improved care for cryptococcal meningitis patients in resource-limited settings is possible, and new treatment possibilities are emerging.

Cryptococcosis

Cryptococcosis is an invasive mycosis caused by pathogenic encapsulated yeasts in the genus Cryptococcus. Cryptococcus gained prominence as a pathogen capable of widespread disease outbreaks in vulnerable populations. We have gained insight into the pathobiology of Cryptococcus, including the yeast' s capacity to adapt to environmental pressures, exploit new geographic environments, and cause disease in both immunocompromised and apparently immunocompetent hosts. Inexpensive, point-of-care testing makes diagnosis more feasible than ever. The associated worldwide burden and mortality remains unacceptably high. Novel screening strategies and preemptive therapy offer promise at making a sustained and much needed impact on this sugar-coated opportunistic mycosis.

Asymptomatic cryptococcal antigen prevalence detected by lateral flow assay in hospitalised HIV-infected patients in São Paulo, Brazil

OBJECTIVE

To determine the prevalence of asymptomatic cryptococcal antigen (CRAG) using lateral flow assay (LFA) in hospitalised HIV-infected patients with CD4 counts <200 cells/μl.

METHODS

Hospitalised HIV-infected patients were prospectively recruited at Instituto de Infectologia Emilio Ribas, a tertiary referral hospital to HIV-infected patients serving the São Paulo State, Brazil. All patients were >18 years old without prior cryptococcal meningitis, without clinical suspicion of cryptococcal meningitis, regardless of antiretroviral (ART) status, and with CD4 counts <200 cells/μl. Serum CRAG was tested by LFA in all patients, and whole blood CRAG was tested by LFA in positive cases.

RESULTS

We enrolled 163 participants of whom 61% were men. The duration of HIV diagnosis was a median of 8 (range, 1-29) years. 26% were antiretroviral (ART)-naïve, and 74% were ART-experienced. The median CD4 cell count was 25 (range, 1-192) cells/μl. Five patients (3.1%; 95%CI, 1.0-7.0%) were asymptomatic CRAG-positive. Positive results cases were cross-verified by performing LFA in whole blood.

CONCLUSIONS

3.1% of HIV-infected inpatients with CD4 <200 cells/μl without symptomatic meningitis had cryptococcal antigenemia in São Paulo, suggesting that routine CRAG screening may be beneficial in similar settings in South America. Our study reveals another targeted population for CRAG screening: hospitalised HIV-infected patients with CD4 <200 cells/μl, regardless of ART status. Whole blood CRAG LFA screening seems to be a simple strategy to prevention of symptomatic meningitis.

Laboratory Diagnosis of Central Nervous System Infection

Central nervous system (CNS) infections are potentially life threatening if not diagnosed and treated early. The initial clinical presentations of many CNS infections are non-specific, making a definitive etiologic diagnosis challenging. Nucleic acid in vitro amplification-based molecular methods are increasingly being applied for routine microbial detection. These methods are a vast improvement over conventional techniques with the advantage of rapid turnaround and higher sensitivity and specificity. Additionally, molecular methods performed on cerebrospinal fluid samples are considered the new gold standard for diagnosis of CNS infection caused by pathogens, which are otherwise difficult to detect. Commercial diagnostic platforms offer various monoplex and multiplex PCR assays for convenient testing of targets that cause similar clinical illness. Pan-omic molecular platforms possess potential for use in this area. Although molecular methods are predicted to be widely used in diagnosing and monitoring CNS infections, results generated by these methods need to be carefully interpreted in combination with clinical findings. This review summarizes the currently available armamentarium of molecular assays for diagnosis of central nervous system infections, their application, and future approaches.

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.

Performance Evaluation of the Becton Dickinson FACSPresto™ Near-Patient CD4 Instrument in a Laboratory and Typical Field Clinic Setting in South Africa

Background

The BD-FACSPresto^™ CD4 is a new, point-of-care (POC) instrument utilising finger-stick capillary blood sampling. This study evaluated its performance against predicate CD4 testing in South Africa.

Methods

Phase-I testing: HIV+ patient samples (n = 214) were analysed on the Presto^™ under ideal laboratory conditions using venous blood. During Phase-II, 135 patients were capillary-bled for CD4 testing on FACSPresto^™, performed according to manufacturer instruction. Comparative statistical analyses against predicate PLG/CD4 method and industry standards were done using GraphPad Prism 6. It included Bland-Altman with 95% limits of agreement (LOA) and percentage similarity with coefficient of variation (%CV) analyses for absolute CD4 count (cells/μl) and CD4 percentage of lymphocytes (CD4%).

Results

In Phase-I, 179/217 samples yielded reportable results with Presto^™ using venous blood filled cartridges. Compared to predicate, a mean bias of 40.4±45.8 (LOA of -49.2 to 130.2) and %similarity (%CV) of 106.1%±7.75 (7.3%) was noted for CD4 absolute counts. In Phase-2 field study, 118/135 capillary-bled Presto^™ samples resulted CD4 parameters. Compared to predicate, a mean bias of 50.2±92.8 (LOA of -131.7 to 232) with %similarity (%CV) 105%±10.8 (10.3%), and 2.87±2.7 (LOA of -8.2 to 2.5) with similarity of 94.7±6.5% (6.83%) noted for absolute CD4 and CD4% respectively. No significant clinical differences were indicated for either parameter using two sampling methods.

Conclusion

The Presto^™ produced remarkable precision to predicate methods, irrespective of venous or capillary blood sampling. A consistent, clinically insignificant over-estimation (5–7%) of counts against PLG/CD4 and equivalency to FACSCount^™ was noted. Further field studies are awaited to confirm longer-term use.

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.

Cryptococcus neoformans infection in malignancy

Cryptococcosis is an opportunistic invasive fungal infection that is well described and easily recognised when it occurs as meningitis in HIV-infected persons. Malignancy and its treatment may also confer a higher risk of infection with Cryptococcus neoformans, but this association has not been as well described. A case of cryptococcosis in a cancer patient is presented, and all cases of coincident C. neoformans infection and malignancy in adults published in the literature in English between 1970 and 2014 are reviewed. Data from these cases were aggregated in order to describe the demographics, type of malignancy, site of infection, clinical manifestations, treatment and outcomes of cryptococcosis in patients with cancer. Haematologic malignancies accounted for 82% of cases, with lymphomas over-represented compared to US population data (66% vs. 53% respectively). Cryptococcosis was reported rarely in patients with solid tumours. Haematologic malignancy patients were more likely to have central nervous system (P < 0.001) or disseminated disease (P < 0.001), receive Amphotericin B as part of initial therapy (P = 0.023), and had higher reported mortality rates than those with solid tumours (P = 0.222). Providers should have heightened awareness of the possibility of cryptococcosis in patients with haematologic malignancy presenting with infection.

Application of Culture-Independent Rapid Diagnostic Tests in the Management of Invasive Candidiasis and Cryptococcosis

The diagnosis of invasive candidiasis (IC) and cryptococcosis is often complicated by slow and insensitive culture-based methods. Such delay results in poor outcomes due to the lack of timely therapeutic interventions. Advances in serological, biochemical, molecular and proteomic approaches have made a favorable impact on this process, improving the timeliness and accuracy of diagnosis with resultant improvements in outcome. This paper will serve as an overview of recent developments in the diagnostic approaches to infections due to these important yeast-fungi.