Summary Background Cryptococcus is the most common cause of meningitis in adults living with HIV in sub-Saharan Africa. Global burden estimates are crucial to guide prevention strategies and to ...determine treatment needs, and we aimed to provide an updated estimate of global incidence of HIV-associated cryptococcal disease. Methods We used 2014 Joint UN Programme on HIV and AIDS estimates of adults (aged >15 years) with HIV and antiretroviral therapy (ART) coverage. Estimates of CD4 less than 100 cells per μL, virological failure incidence, and loss to follow-up were from published multinational cohorts in low-income and middle-income countries. We calculated those at risk for cryptococcal infection, specifically those with CD4 less than 100 cells/μL not on ART, and those with CD4 less than 100 cells per μL on ART but lost to follow-up or with virological failure. Cryptococcal antigenaemia prevalence by country was derived from 46 studies globally. Based on cryptococcal antigenaemia prevalence in each country and region, we estimated the annual numbers of people who are developing and dying from cryptococcal meningitis. Findings We estimated an average global cryptococcal antigenaemia prevalence of 6·0% (95% CI 5·8–6·2) among people with a CD4 cell count of less than 100 cells per μL, with 278 000 (95% CI 195 500–340 600) people positive for cryptococcal antigen globally and 223 100 (95% CI 150 600–282 400) incident cases of cryptococcal meningitis globally in 2014. Sub-Saharan Africa accounted for 73% of the estimated cryptococcal meningitis cases in 2014 (162 500 cases 95% CI 113 600–193 900). Annual global deaths from cryptococcal meningitis were estimated at 181 100 (95% CI 119 400–234 300), with 135 900 (75%; 95% CI 93 900–163 900) deaths in sub-Saharan Africa. Globally, cryptococcal meningitis was responsible for 15% of AIDS-related deaths (95% CI 10–19). Interpretation Our analysis highlights the substantial ongoing burden of HIV-associated cryptococcal disease, primarily in sub-Saharan Africa. Cryptococcal meningitis is a metric of HIV treatment programme failure; timely HIV testing and rapid linkage to care remain an urgent priority. Funding None.
HIV-associated cryptococcal meningitis is by far the most common cause of adult meningitis in many areas of the world that have high HIV seroprevalence. In most areas in Sub-Saharan Africa, the ...incidence of cryptococcal meningitis is not decreasing despite availability of antiretroviral therapy, because of issues of adherence and retention in HIV care. In addition, cryptococcal meningitis in HIV-seronegative individuals is a substantial problem: the risk of cryptococcal infection is increased in transplant recipients and other individuals with defects in cell-mediated immunity, and cryptococcosis is also reported in the apparently immunocompetent. Despite therapy, mortality rates in these groups are high. Over the past 5 years, advances have been made in rapid point-of-care diagnosis and early detection of cryptococcal antigen in the blood. These advances have enabled development of screening and pre-emptive treatment strategies aimed at preventing the development of clinical infection in patients with late-stage HIV infection. Progress in optimizing antifungal combinations has been aided by evaluation of the clearance rate of infection by using serial quantitative cultures of cerebrospinal fluid (CSF). Measurement and management of raised CSF pressure, a common complication, is a vital component of care. In addition, we now better understand protective immune responses in HIV-associated cases, immunogenetic predisposition to infection, and the role of immune-mediated pathology in patients with non-HIV associated infection and in the context of HIV-associated immune reconstitution reactions.
Understanding the host immune response during cryptococcal meningitis (CM) is of critical importance for the development of immunomodulatory therapies. We profiled the cerebrospinal fluid (CSF) ...immune-response in ninety patients with HIV-associated CM, and examined associations between immune phenotype and clinical outcome. CSF cytokine, chemokine, and macrophage activation marker concentrations were assayed at disease presentation, and associations between these parameters and microbiological and clinical outcomes were examined using principal component analysis (PCA). PCA demonstrated a co-correlated CSF cytokine and chemokine response consisting primarily of Th1, Th2, and Th17-type cytokines. The presence of this CSF cytokine response was associated with evidence of increased macrophage activation, more rapid clearance of Cryptococci from CSF, and survival at 2 weeks. The key components of this protective immune-response were interleukin (IL)-6 and interferon-γ, IL-4, IL-10 and IL-17 levels also made a modest positive contribution to the PC1 score. A second component of co-correlated chemokines was identified by PCA, consisting primarily of monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α). High CSF chemokine concentrations were associated with low peripheral CD4 cell counts and CSF lymphocyte counts and were predictive of immune reconstitution inflammatory syndrome (IRIS). In conclusion CSF cytokine and chemokine profiles predict risk of early mortality and IRIS in HIV-associated CM. We speculate that the presence of even minimal Cryptococcus-specific Th1-type CD4+ T-cell responses lead to increased recruitment of circulating lymphocytes and monocytes into the central nervous system (CNS), more effective activation of CNS macrophages and microglial cells, and faster organism clearance; while high CNS chemokine levels may predispose to over recruitment or inappropriate recruitment of immune cells to the CNS and IRIS following peripheral immune reconstitution with ART. These results provide a rational basis for future studies of immune modulation in CM, and demonstrate the potential of baseline immune profiling to identify CM patients most at risk of mortality and subsequent IRIS.
Research into life-threatening illnesses which require emergency hospitalisation is essential. This group of patients is unique in that they are experiencing an unfolding emergency when they are ...approached, enrolled, and followed up in a research study. We aimed to synthesise qualitative data from trial participants and surrogate decision-makers to deepen our understanding and inform the design and conduct of future clinical trials for life-threatening illnesses.
We conducted a critical interpretive synthesis of qualitative data from trial participants and surrogate decision-makers related to the experience of participating in a clinical research study when suffering from a life-threatening illness. A scoping review informed a systematic review of published data. We searched research databases and reviewed papers for inclusion. Primary data and interpretations of data were extracted from each paper. Data were analysed using reciprocal translational analysis, refutational synthesis, and lines of argument synthesis to develop a synthetic construct.
Twenty-two papers were included. Most individuals had no previous knowledge or experience with clinical research. Individuals making decisions were directly experiencing or witness to an unfolding emergency which came with a myriad of physical and psychological symptoms. It was difficult to differentiate clinical research and routine care, and understanding of core concepts around research, particularly randomisation and equipoise, was limited. We found that this led to an underestimation of risk, an overestimation of benefit, and an expectation of being allocated to the intervention arm. The decision-making process was heavily influenced by trust in the research team. Individuals suggested that abbreviated information, presented in different ways and continuously throughout the research process, would have increased knowledge and satisfaction with the research process.
Individuals suffering from a life-threatening illness who are being invited to participate in clinical research need to be managed in a way that adapts to the severity of their illness and there is a need to tailor research processes, including informed consent, accordingly. We provide suggestions for further research and implementation work around research participation for individuals suffering from a life-threatening illness.
PROSPERO CRD42020207296.
Background. Cryptococcal meningitis is a leading cause of death in patients with acquired immunodeficiency syndrome and contributes substantially to the high early mortality in antiretroviral ...treatment (ART) programs in low-resource settings. Screening for cryptococcal antigen in patients who enroll in ART programs may identify those at risk of cryptococcal meningitis and permit targeted use of preemptive therapy. Methods. In this retrospective study, cryptococcal antigen was measured in stored plasma samples obtained from patients when they enrolled in a well-characterized ART cohort in South Africa. The predictive value of screening for cryptococcal antigen before initiation of ART for development of microbiologically confirmed cryptococcal meningitis or death during the first year of follow-up was determined. Results. Of 707 participants with a baseline median CD4 cell count of 97 cells/µL (interquartile range, 46–157 cells/µL), 46 (7%) were positive for cryptococcal antigen. Antigenemia was 100% sensitive for predicting development of cryptococcal meningitis during the first year of ART, and in multivariate analysis, it was an independent predictor of mortality (adjusted hazard ratio, 3.2; 95% confidence interval, 1.5–6.6). Most cases (92%) of cryptococcal meningitis developed in patients with a CD4 cell count ⩽100 cells/µL. In this subset of patients, a cryptococcal antigen titer ⩾1:8 was 100% sensitive and 96% specific for predicting incident cryptococcal meningitis during the first year of ART in those with no history of the disease. Conclusions. Cryptococcal antigen screening before initiation of ART in patients with a CD4 cell count ⩽100 cells/µL is highly effective for identifying those at risk of cryptococcal meningitis and death and might permit implementation of a targeted preemptive treatment strategy.
Cryptococcal meningitis (CM)-related mortality may be prevented by screening patients for sub-clinical cryptococcal antigenaemia (CRAG) at antiretroviral-therapy (ART) initiation and pre-emptively ...treating those testing positive. Prior to programmatic implementation in South Africa we performed a cost-effectiveness analysis of alternative preventive strategies for CM.
Cost-effectiveness analysis.
Using South African data we modelled the cost-effectiveness of four strategies for patients with CD4 cell-counts <100 cells/µl starting ART 1) no screening or prophylaxis (standard of care), 2) universal primary fluconazole prophylaxis, 3) CRAG screening with fluconazole treatment if antigen-positive, 4) CRAG screening with lumbar puncture if antigen-positive and either amphotericin-B for those with CNS disease or fluconazole for those without. Analysis was limited to the first year of ART.
The least costly strategy was CRAG screening followed by high-dose fluconazole treatment of all CRAG-positive individuals. This strategy dominated the standard of care at CRAG prevalence ≥0.6%. Although CRAG screening followed by lumbar puncture in all antigen-positive individuals was the most effective strategy clinically, the incremental benefit of LPs and amphotericin therapy for those with CNS disease was small and additional costs were large (US$158 versus US$51 per person year; incremental cost effectiveness ratio(ICER) US$889,267 per life year gained). Both CRAG screening strategies are less costly and more clinically effective than current practice. Primary prophylaxis is more effective than current practice, but relatively cost-ineffective (ICER US$20,495).
CRAG screening would be a cost-effective strategy to prevent CM-related mortality among patients initiating ART in South Africa. These findings provide further justification for programmatic implementation of CRAG screening.
The presentation and causes of adult meningitis in South Africa have changed substantially as a result of HIV. Knowledge of aetiology and laboratory findings in patients presenting with meningitis ...are important in guiding management. We performed a retrospective study to determine these findings in a setting of high HIV and TB prevalence in Cape Town.
Patients undergoing lumbar punctures between 1st January 2006 and 31st December 2008 at a public sector referral hospital were studied. Cases were classified by microbiological diagnosis, or in the absence of definitive microbiology as 1) normal CSF (neutrophils < or = 1 x 10(6)/L, lymphocytes < or = 5 x 10(6)/L, protein < or = 0.5 g/dL, glucose > or =1.5 mmol/L), 2) minor abnormalities (neutrophils 2-5, lymphocytes 6-20, protein 0.51-1.0, glucose 1.0-1.49) or 3) markedly abnormal (neutrophils>5, lymphocytes>20, protein>1.0, glucose<1.0).
5578 LPs were performed on 4549 patients, representing 4961 clinical episodes. Of these, 2293 had normal CSF and 931 had minor abnormalities and no aetiology identified. Of the remaining 1737, microbiological diagnoses were obtained in 820 (47%). Cryptococcus accounted for 63% (514) of microbiological diagnoses, TB for 28% (227), bacterial meningitis for 8% (68). Of the remaining 917 who had marked abnormalities, the majority (59%) had a sterile lymphocytic CSF. Of note 16% (81) patients with confirmed Cryptococcus, 5% (12) with TB and 4% (3) with bacterial meningitis had normal CSF cell-counts and biochemistry.
Cryptococcal and tuberculous meningitis are now the commonest causes of adult meningitis in this setting. TB meningitis is probably underdiagnosed by laboratory investigation, as evidence by the large numbers presenting with sterile lymphocytic markedly abnormal CSFs.
Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who ...could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts.
We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models.
Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval CI, 5.7%-7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%-2.7%; 21 studies) among patients with CD4 count 101-200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%-22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101-200 cells/µL. CrAg prevalence was higher among inpatients (9.8% 95% CI, 4.0%-15.5%) compared with outpatients (6.3% 95% CI, 5.3%-7.4%).
The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL.
HIV infection profoundly impairs the immune mechanisms needed to control and clear Leishmania infection, and outcomes in patients with HIV-associated visceral leishmaniasis are poor. This review ...summarizes recent work describing the epidemiology, presentation and outcomes of HIV-associated visceral leishmaniasis and discusses advances in diagnosis and management.
Studies have shown that serological tests can effectively diagnose HIV-associated visceral leishmaniasis, with a sensitivity of 98% if direct agglutination test and rK39 assays are used in combination. Few data exist to guide treatment recommendations. Observational data show high rates of toxicity and treatment failure with pentavalent antimonials, and their use is no longer recommended. Liposomal amphotericin B (L-AmB) is better tolerated, but outcomes are suboptimal, with mortality rates of 7-12%, and parasitological failure rates of up to 32%. Initial reports suggest that L-AmB and miltefosine in combination may be effective in HIV-associated visceral leishmaniasis; however, clinical trial data are lacking. Secondary prophylaxis reduces the rate of relapse, but optimal regimens have not been defined, and optimal timing of antiretroviral therapy initiation in patients with visceral leishmaniasis is unknown.
Recent studies have demonstrated the inadequacy of current treatments for HIV-associated visceral leishmaniasis. Clinical trials are needed to improve early diagnosis, develop combination therapies and define effective secondary prophylaxis regimens.
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