Symptomatic Relapse of HIV‐Associated Cryptococcal Meningitis after Initial Fluconazole Monotherapy: The Role of Fluconazole Resistance and Immune Reconstitution

Challenges in diagnosis and management of Cryptococcal immune reconstitution inflammatory syndrome (IRIS) in resource limited settings

In many resource-limited settings, cryptococcal meningitis (CM) contributes up to 20% of all deaths with further complications due to Immune Reconstitution Inflammatory Syndrome (IRIS). We present a case report on a patient who developed CM-IRIS and then subsequent CM-relapse with a fluconazole-resistant organism and then later CM-IRIS once again, manifesting as cystic cryptococcomas, hydrocephalus, and sterile CSF. In this case we, demonstrate that CM-IRIS and persistent low level cryptococcal infection are not mutually exclusive phenomena. The management of IRIS with corticosteroids may increase the risk of culture positive CM-relapse which may further increase the risk of recurrent IRIS and resulting complications including death. We also highlight the role of imaging and fluconazole resistance testing in patients with recurrent meningitis and the importance of CSF cultures in guiding treatment decisions.

The antidepressant sertraline provides a promising therapeutic option for neurotropic cryptococcal infections

Therapeutic treatment for systemic mycoses is severely hampered by the extremely limited number of antifungals. The difficulty of treatment of fungal infections in the central nervous system is further compounded by the poor central nervous system (CNS) penetration of most antifungals due to the blood-brain barrier. Only a few fungistatic azole drugs, such as fluconazole, show reasonable CNS penetration. Here we demonstrate that sertraline (Zoloft), the most frequently prescribed antidepressant, displays potent antifungal activity against Cryptococcus neoformans, the major causative agent of fungal meningitis. In in vitro assays, this neurotropic drug is fungicidal to all natural Cryptococcus isolates tested at clinically relevant concentrations. Furthermore, sertraline interacts synergistically or additively with fluconazole against Cryptococcus. Importantly, consistent with our in vitro observations, sertraline used alone reduces the brain fungal burden at an efficacy comparable to that of fluconazole in a murine model of systemic cryptococcosis. It works synergistically with fluconazole in reducing the fungal burden in brain, kidney, and spleen. In contrast to its potency against Cryptococcus, sertraline is less effective against strains of Candida species and its interactions with fluconazole against Candida strains are often antagonistic. Therefore, our data suggest the unique application of sertraline against cryptococcosis. To understand the antifungal mechanisms of sertraline, we screened a whole-genome deletion collection of Saccharomyces cerevisiae for altered sertraline susceptibility. Gene ontology analyses of selected mutations suggest that sertraline perturbs translation. In vitro translation assays using fungal cell extracts show that sertraline inhibits protein synthesis. Taken together, our findings indicate the potential of adopting this antidepressant in treating cryptococcal meningitis.

Central nervous system immune reconstitution inflammatory syndrome in AIDS: experience of a Mexican neurological centre

BACKGROUND

Highly active antiretroviral therapy (HAART) restores the inflammatory immune response in AIDS patients and it may unmask previous subclinical infections or paradoxically exacerbate symptoms of opportunistic infections. Up to 25% of patients receiving HAART develop immune reconstitution inflammatory syndrome (IRIS). We describe six patients with IRIS central nervous system (CNSIRIS) manifestations emphasizing the relevance of CSF cultures and neuroimaging in early diagnosis and management.

METHODS

Patients with CNSIRIS were identified among hospitalized HIV-infected patients that started HAART from January 2002 through December 2007 at a referral neurological center in Mexico.

RESULTS

One-hundred and forty-two HIV-infected patients with neurological signs were hospitalized, 64 of which had received HAART, and six (9.3%) developed CNSIRIS. Five patients were male. Two cases of tuberculosis, two of cryptococcosis, one of brain toxoplasmosis, and one possible PML case were found. IRIS onset occurred within 12 weeks of HAART in five patients. Anti-infective therapy was continued. In one case, HAART was temporarily suspended. In long-term follow-up the clinical condition improved in all patients.

CONCLUSIONS

CNSIRIS associated to opportunistic infections appeared in 9% of patients receiving HAART. Interestingly, no cases of malignancy or neoplasm IRIS-related were found. Frequent clinical assessment and neuroimaging studies supported diagnosis and treatment. Risk factors were similar to those found in other series.

Antifungal drug resistance: mechanisms, epidemiology, and consequences for treatment

Antifungal resistance continues to grow and evolve and complicate patient management, despite the introduction of new antifungal agents. In vitro susceptibility testing is often used to select agents with likely activity for a given infection, but perhaps its most important use is in identifying agents that will not work, i.e., to detect resistance. Standardized methods for reliable in vitro antifungal susceptibility testing are now available from the Clinical and Laboratory Standards Institute (CLSI) in the United States and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in Europe. Data gathered by these standardized tests are useful (in conjunction with other forms of data) for calculating clinical breakpoints and epidemiologic cutoff values (ECVs). Clinical breakpoints should be selected to optimize detection of non-wild-type (WT) strains of pathogens, and they should be species-specific and not divide WT distributions of important target species. ECVs are the most sensitive means of identifying strains with acquired resistance mechanisms. Various mechanisms can lead to acquired resistance of Candida species to azole drugs, the most common being induction of the efflux pumps encoded by the MDR or CDR genes, and acquisition of point mutations in the gene encoding for the target enzyme (ERG11). Acquired resistance of Candida species to echinocandins is typically mediated via acquisition of point mutations in the FKS genes encoding the major subunit of its target enzyme. Antifungal resistance is associated with elevated minimum inhibitory concentrations, poorer clinical outcomes, and breakthrough infections during antifungal treatment and prophylaxis. Candidemia due to Candida glabrata is becoming increasingly common, and C glabrata isolates are increasingly resistant to both azole and echinocandin antifungal agents. This situation requires continuing attention. Rates of azole-resistant Aspergillus fumigatus are currently low, but there are reports of emerging resistance, including multi-azole resistant isolates in parts of Europe.

Identification of a Cryptococcus neoformans cytochrome P450 lanosterol 14α-demethylase (Erg11) residue critical for differential susceptibility between fluconazole/voriconazole and itraconazole/posaconazole

Cryptococcus neoformans strains resistant to azoles due to mutations causing alterations in the ERG11 gene, encoding lanosterol 14α-demethylase, have rarely been reported. In this study, we have characterized a C. neoformans serotype A strain that is resistant to high concentrations of fluconazole (FLC). This strain, which was isolated from an FLC-treated patient, contained five missense mutations in the ERG11 gene compared to the sequence of reference strain H99. Molecular manipulations of the ERG11 gene coupled with susceptibility to triazole revealed that a single missense mutation resulting in the replacement of tyrosine by phenylalanine at amino acid 145 was sufficient to cause the high FLC resistance of the strain. Importantly, this newly identified point mutation in the ERG11 gene of C. neoformans afforded resistance to voriconazole (VRC) but increased susceptibility to itraconazole (ITC) and posaconazole (PSC), which are structurally similar to each other but distinct from FLC/VRC. The in vitro susceptibility/resistance of the strains with or without the missense mutation was reflected in the therapeutic efficacy of FLC versus ITC in the animals infected with the strains. This study shows the importance of the Y145F alteration of Erg11 in C. neoformans for manifestation of differential susceptibility toward different triazoles. It underscores the necessity of in vitro susceptibility testing for each FLC-resistant C. neoformans clinical isolate against different groups of azoles in order to assist patient management.

Short course amphotericin B with high dose fluconazole for HIV-associated cryptococcal meningitis

OBJECTIVE

To define more rapidly effective initial antifungal regimens sustainable in resource-constrained settings.

METHODS

Cohort study in SW Uganda: Thirty HIV-seropositive, antiretroviral therapy-naïve, patients with first episode cryptococcal meningitis were treated with high dose fluconazole (1200 mg/d for 2 weeks, then 800 mg/d until ART started) plus amphotericin B (AmB, 1 mg/kg/d), with routine normal saline and potassium supplementation, for the initial 5 days. Outcome measures were early fungicidal activity (EFA), determined by serial quantitative CSF cultures, safety, and mortality.

RESULTS

EFA was -0.30 ± 0.11 log CFU/day calculated over the first 2 weeks of treatment, with no reduction in the rate of clearance between days 5 and 14. There was no grade IV hypokalemia or elevated creatinine, and no grade III or IV anemia or elevation of ALT. AmB or high dose fluconazole were not stopped early in any patient. Mortality was 23% at 2, and 28% at 10 weeks.

CONCLUSIONS

Short course AmB was associated with rapid clearance of infection and was well-tolerated, suggesting it could be used safely in many centres currently relying on fluconazole monotherapy. Phase III trials are needed in African centres to compare short course with the standard 2-week course of AmB.

Regulatory circuitry governing fungal development, drug resistance, and disease

Pathogenic fungi have become a leading cause of human mortality due to the increasing frequency of fungal infections in immunocompromised populations and the limited armamentarium of clinically useful antifungal drugs. Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the leading causes of opportunistic fungal infections. In these diverse pathogenic fungi, complex signal transduction cascades are critical for sensing environmental changes and mediating appropriate cellular responses. For C. albicans, several environmental cues regulate a morphogenetic switch from yeast to filamentous growth, a reversible transition important for virulence. Many of the signaling cascades regulating morphogenesis are also required for cells to adapt and survive the cellular stresses imposed by antifungal drugs. Many of these signaling networks are conserved in C. neoformans and A. fumigatus, which undergo distinct morphogenetic programs during specific phases of their life cycles. Furthermore, the key mechanisms of fungal drug resistance, including alterations of the drug target, overexpression of drug efflux transporters, and alteration of cellular stress responses, are conserved between these species. This review focuses on the circuitry regulating fungal morphogenesis and drug resistance and the impact of these pathways on virulence. Although the three human-pathogenic fungi highlighted in this review are those most frequently encountered in the clinic, they represent a minute fraction of fungal diversity. Exploration of the conservation and divergence of core signal transduction pathways across C. albicans, C. neoformans, and A. fumigatus provides a foundation for the study of a broader diversity of pathogenic fungi and a platform for the development of new therapeutic strategies for fungal disease.

Antifungal susceptibilities of Cryptococcus neoformans cerebrospinal fluid isolates from AIDS patients in Kenya

Poor susceptibility of Cryptococcus neoformans to fluconazole (FLC) is a matter of concern among clinicians in Africa. The emergence of resistance to FLC was recently reported in Kenya, but it is not known whether it is widespread. Thus, there is need for more antifungal drug susceptibility studies in Kenya. The aim of this study was to measure the in vitro antifungal drug susceptibilities of incident C. neoformans isolates from acquired immunodeficiency syndrome patients in Kenya. Antifungal susceptibility testing was performed in 67 C. neoformans isolates by broth microdilution method as outlined in the Clinical and Laboratory Standards Institute document M27-A3 using FLC, amphotericin B (AMB), voriconazole (VOR), ravuconazole (RAV) and flucytosine (5-FC). Isolates were grown on l-canavanine glycine bromothymol blue medium for serotype identification. Six per cent of the isolates were identified as C. neoformans var. gattii serotype B or C and 94% as C. neoformans var. neoformans. All isolates tested were susceptible to AMB, VOR and RAV (100%), and high susceptibilities were seen to FLC (97%), and 5-FC (90%). Only 3% and 10% of the isolates' susceptibility to FLC and 5-FC, respectively, was dose-dependent or intermediate. These results demonstrate high susceptibilities of incident C. neoformans isolates to FLC and AMB, antifungals used for treatment of cryptococcal meningitis in Kenya.

Trends in antifungal drug susceptibility of Cryptococcus neoformans isolates obtained through population-based surveillance in South Africa in 2002-2003 and 2007-2008

Cryptococcus neoformans is the most common cause of meningitis among adult South Africans with HIV infection/AIDS. Widespread use of fluconazole for treatment of cryptococcal meningitis and other HIV-associated opportunistic fungal infections in South Africa may lead to the emergence of isolates with reduced fluconazole susceptibility. MIC testing using a reference broth microdilution method was used to determine if isolates with reduced susceptibility to fluconazole or amphotericin B had emerged among cases of incident disease. Incident isolates were tested from two surveillance periods (2002-2003 and 2007-2008) when population-based surveillance was conducted in Gauteng Province, South Africa. These isolates were also tested for susceptibility to flucytosine, itraconazole, voriconazole, and posaconazole. Serially collected isolate pairs from cases at several large South African hospitals were also tested for susceptibility to fluconazole. Of the 487 incident isolates tested, only 3 (0.6%) demonstrated a fluconazole MIC of ≥ 16 μg/ml; all of these isolates were from 2002-2003. All incident isolates were inhibited by very low concentrations of amphotericin B and exhibited very low MICs to voriconazole and posaconazole. Of 67 cases with serially collected isolate pairs, only 1 case was detected where the isolate collected more than 30 days later had a fluconazole MIC value significantly higher than the MIC of the corresponding incident isolate. Although routine antifungal susceptibility testing of incident isolates is not currently recommended in clinical settings, it is still clearly important for public health to periodically monitor for the emergence of resistance.

Cryptococcal immune reconstitution inflammatory syndrome in HIV-1-infected individuals: proposed clinical case definitions

Cryptococcal immune reconstitution inflammatory syndrome (IRIS) may present as a clinical worsening or new presentation of cryptococcal disease after initiation of antiretroviral therapy (ART), and is thought to be caused by recovery of cryptococcus-specific immune responses. We have reviewed reports of cryptococcal IRIS and have developed a consensus case definition specifically for paradoxical crytopcoccal IRIS in patients with HIV-1 and known cryptococcal disease before ART, and a separate definition for incident cryptococcosis developed during ART (termed ART-associated cryptococcosis), for which a proportion of cases are likely to be unmasking cryptococcal IRIS. These structured case definitions are intended to aid design of future clinical, epidemiological, and immunopathological studies of cryptococcal IRIS, to standardise diagnostic criteria, and to facilitate comparisons between studies. As for definitions of tuberculosis-associated IRIS, definitions for cryptococcal IRIS should be regarded as preliminary until further insights into the immunopathology of IRIS permit their refinement.

Cost-effectiveness of primary prophylaxis of AIDS associated cryptococcosis in Cambodia

Background

Cryptococcal infection is a frequent cause of mortality in Cambodian HIV-infected patients with CD4+ count ≤100 cells/µl. This study assessed the cost-effectiveness of three strategies for cryptococcosis prevention in HIV-infected patients.

Methods

A Markov decision tree was used to compare the following strategies at the time of HIV diagnosis: no intervention, one time systematic serum cryptococcal antigen (CRAG) screening and treatment of positive patients, and systematic primary prophylaxis with fluconazole. The trajectory of a hypothetical cohort of HIV-infected patients with CD4+ count ≤100 cells/µl initiating care was simulated over a 1-year period (cotrimoxazole initiation at enrollment; antiretroviral therapy within 3 months). Natural history and cost data (US$ 2009) were from Cambodia. Efficacy data were from international literature.

Results

In a population in which 81% of patients had a CD4+ count ≤50 cells/ µl and 19% a CD4+ count between 51–100 cells/µl, the proportion alive 1 year after enrolment was 61% (cost $ 472) with no intervention, 70% (cost $ 483) with screening, and 72% (cost $ 492) with prophylaxis. After one year of follow-up, the cost-effectiveness of screening vs. no intervention was US$ 180/life year gained (LYG). The cost-effectiveness of prophylaxis vs. screening was $ 511/LYG. The cost-effectiveness of prophylaxis vs. screening was estimated at $1538/LYG if the proportion of patients with CD4+ count ≤50 cells/µl decreased by 75%.

Conclusion

In a high endemic area of cryptococcosis and HIV infection, serum CRAG screening and prophylaxis are two cost effective strategies to prevent AIDS associated cryptococcosis in patients with CD4+ count ≤100 cells/µl, at a short-term horizon, screening being more cost-effective but less effective than prophylaxis. Systematic primary prophylaxis may be preferred in patients with CD4+ below 50 cells/µl while systematic serum CRAG screening for early targeted treatment may be preferred in patients with CD4+ between 51–100 cells/µl.

An update on Cryptococcus among HIV-infected patients

Cryptococcus remains an important opportunistic infection in HIV patients despite considerable declines in prevalence during the highly active antiretroviral therapy era. This is particularly apparent in sub-Saharan Africa, where Cryptococcus continues to cause significant mortality and morbidity. This review discusses the microbiology, epidemiology, pathogenesis and clinical presentation of cryptococcal infections in HIV patients. Additionally, a detailed approach to the management of cryptococcosis is provided.

Cryptococcal meningitis in non-HIV-infected patients in a Chinese tertiary care hospital, 1997-2007

Information remains sparse about non-HIV patients with cryptococcal meningitis in the era of triazole therapy. Particularly of interest are the clinical manifestations and prognosis of the infection in these previously healthy patients. We retrospectively reviewed 154 non-HIV-infected patients with cryptococcal meningitis who presented in our hospital from 1997 to 2007. We compared the clinical features and outcomes between predisposed and otherwise healthy hosts. The number of cases per year showed a steady increase over time. The majority of patients were otherwise apparently healthy (103 patients, 66.9%) and predisposing factors were identified in only 51 (33.1%) patients. Corticosteroid medication accounted for the most common underlying factor in these cases (n = 21). Morbidity was appallingly high, with seizures in 28.6%, cranial nerves palsies in 51.5% and cerebral herniation in 19.5%. Despite these complications, overall mortality during 1 year was 28.7% (41/143), close to that reported from other centers with non-HIV patients. Death attributed to cryptococcosis occurred in 19.6% (28/143) patients with most receiving amphotericin B as a component of their initial therapy. Among surviving patients who had lumbar punctures at weeks 2 and 10, those given amphotericin B for initial therapy achieved higher rates of overall response than those receiving initial fluconazole therapy at either week 2 (84.4% of 96 patients vs. 33.3% of 24 patients, P <0.001) or week 10 (85.0% of 93 patients vs. 66.7% of 24 patients, P = 0.041). In multivariate analysis, coma, cerebral herniation, and initial antifungal therapy without amphotericin B were independently correlated with both increased overall and attributable mortality, while advanced age (>/= 60 years) was correlated with increased overall mortality only. Patients with apparently normal immune status were overall younger than those who were immunocompromised. In addition, previously healthy patients for whom diagnosis was delayed had more severe disease, experiencing more brain herniation, coma, seizures, hydrocephalus and more surgical shunt procedures. On the other hand, immunocompromised patients were more commonly found to have high fever and brain parenchymal involvement. However, both groups had a similar treatment response and 1-year survival.

Diagnosis of cryptococcal and tuberculous meningitis in a resource-limited African setting

OBJECTIVES

Cryptococcal meningitis (CM) and tuberculous meningitis (TBM) are common in HIV-infected adults in Africa and difficult to diagnose. Inaccurate diagnosis results in adverse outcomes. We describe patterns of meningitis in a Malawian hospital, focusing on features which differentiate CM and TBM with the aim to derive an algorithm using only clinical and basic laboratory data available in this resource-poor setting.

METHODS

Consecutive patients admitted with meningitis were prospectively recruited, clinical features were recorded and cerebrospinal fluid (CSF) was examined.

RESULTS

A total of 573 patients were recruited, and 263 (46%) had CSF consistent with meningitis. One hundred and twelve (43%) had CM and 46 (18%) had TBM. CM was associated with high CSF opening pressure and low CSF leukocyte count. Fever, neck stiffness and reduced conscious level were associated with TBM. A diagnostic index was constructed demonstrating sensitivity 83%and specificity 79% for the differentiation of CM and TBM. An algorithm was derived with 92% sensitivity for the diagnosis of CM, but only 58% specificity.

CONCLUSIONS

Although we demonstrate features associated with CM and TBM, a sufficiently sensitive and specific diagnostic algorithm could not be derived, suggesting that the diagnosis of CM and TBM in resource-limited settings still requires better access to laboratory tools.

Update on immune reconstitution inflammatory syndrome: progress and unanswered questions

The immune reconstitution inflammatory syndrome (IRIS) is characterized by clinical deterioration occurring after the initiation of effective antiretroviral therapy (ART) and results from a disordered and exuberant immune response. The syndrome may present as paradoxical IRIS or unmasking IRIS, depending on whether an opportunistic infection was recognized and treated before ART initiation. Numerous descriptions of IRIS caused by many pathogens were published in the years after the introduction of effective ART. In recent years, with enhanced rollout of ART in resource-limited settings, attention has again focused on IRIS because of the enormous burden of opportunistic infections. This review highlights recent findings elucidating risk factors for and the pathogenesis and treatment of IRIS.

Overexpression of TUF1 restores respiratory growth and fluconazole sensitivity to a Cryptococcus neoformans vad1Delta mutant

The yeast-like fungus Cryptococcus neoformans favours respiration as a mechanism of energy production, and thus depends heavily on mitochondrial function. Previous studies of a C. neoformansvad1Δ mutant revealed reduced expression of the mitochondrial elongation factor TUF1 and defects in glycerol utilization, consistent with mitochondrial dysfunction. In this study, we found that in trans expression of TUF1 in the vad1Δ mutant suppressed the mitochondrial defects, including growth on respiration-dependent carbon sources and fluconazole resistance, associated with VAD1 deletion. Tetracycline, an inhibitor of mitochondrial translation, was found to confer resistance to fluconazole in the wild-type and vad1Δ mutant, whereas the fluconazole susceptibility of the TUF1-overexpressing strain was unaffected by tetracycline treatment. In the presence of fluconazole, the vad1Δ mutant exhibited increased activation of the global transcriptional regulator Sre1. TUF1 overexpression failed to alter cleavage of Sre1 in response to fluconazole in the vad1Δ mutant, suggesting that TUF1 repression in the vad1Δ mutant is distal to Sre1, or that it occurs through an independent pathway.

Cryptococcus neoformans overcomes stress of azole drugs by formation of disomy in specific multiple chromosomes

Cryptococcus neoformans is a haploid environmental organism and the major cause of fungal meningoencephalitis in AIDS patients. Fluconazole (FLC), a triazole, is widely used for the maintenance therapy of cryptococcosis. Heteroresistance to FLC, an adaptive mode of azole resistance, was associated with FLC therapy failure cases but the mechanism underlying the resistance was unknown. We used comparative genome hybridization and quantitative real-time PCR in order to show that C. neoformans adapts to high concentrations of FLC by duplication of multiple chromosomes. Formation of disomic chromosomes in response to FLC stress was observed in both serotype A and D strains. Strains that adapted to FLC concentrations higher than their minimal inhibitory concentration (MIC) contained disomies of chromosome 1 and stepwise exposure to even higher drug concentrations induced additional duplications of several other specific chromosomes. The number of disomic chromosomes in each resistant strain directly correlated with the concentration of FLC tolerated by each strain. Upon removal of the drug pressure, strains that had adapted to high concentrations of FLC returned to their original level of susceptibility by initially losing the extra copy of chromosome 1 followed by loss of the extra copies of the remaining disomic chromosomes. The duplication of chromosome 1 was closely associated with two of its resident genes: ERG11, the target of FLC and AFR1, the major transporter of azoles in C. neoformans. This adaptive mechanism in C. neoformans may play an important role in FLC therapy failure of cryptococcosis leading to relapse during azole maintenance therapy.

Cryptococcus neoformans is an environmental fungus that causes life threatening brain disease, primarily in AIDS patients. The disease is estimated to claim 700,000 lives annually world-wide but most heavily in Africa. Fluconazole (FLC), a fungistatic antifungal drug, is commonly used to treat patients for long term maintenance therapy. Recurrence of cryptococcosis in AIDS patients undergoing FLC maintenance therapy has been increasingly reported. Heteroresistance, an adaptive azole resistance, was associated with FLC therapy failure cases but the mechanism underlying the resistance was unknown. We previously described that C. neoformans strains are innately heteroresistant to FLC; each strain producing a fraction of subpopulation that can tolerate a high concentration of the drug. These resistant subpopulations revert to original phenotype during maintenance in drug free media. Various methods including cDNA microarrays, comparative genome hybridization and quantitative PCR have been applied to uncover the mechanism involved in the adaptation of C. neoformans to high concentrations of FLC and subsequent loss of resistance upon the removal of drug pressure. We discovered that C. neoformans adapts to high concentration of FLC by formation of disomy in multiple chromosomes. The removal of drug pressure results in a sequential loss of the extra chromosomal copies. It is likely that this novel mechanism of adaptation contributes to the failure of FLC therapy for cryptococcosis.

Epidemiology of invasive mycoses in North America

The incidence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections may be broken into two broad categories: opportunistic and endemic. The most important agents of the opportunistic mycoses are Candida spp., Cryptococcus neoformans, Pneumocystis jirovecii, and Aspergillus spp. (although the list of potential pathogens is ever expanding); while the most commonly encountered endemic mycoses are due to Histoplasma capsulatum, Coccidioides immitis/posadasii, and Blastomyces dermatitidis. This review discusses the epidemiologic profiles of these invasive mycoses in North America, as well as risk factors for infection, and the pathogens' antifungal susceptibility.

Polymyxin B, in combination with fluconazole, exerts a potent fungicidal effect

OBJECTIVES

The objective of this study was to identify existing clinical compounds that either possess a fungicidal activity alone or can act synergistically with fungistatic antifungals.

METHODS

We screened a clinical compound library for drugs that exhibited anti-Aspergillus activity. Among selected compounds, the cationic peptide antibiotic polymyxin B was chosen for further characterization because it can be used parenterally and topically. The fungicidal effect of polymyxin B and its synergistic interactions with azole antifungals were tested against a variety of fungal species. The toxicity of the drug combination of polymyxin B and fluconazole was compared with that of each drug alone in mammalian cell cultures.

RESULTS

We found that polymyxin B possesses a broad-spectrum antifungal activity at relatively high concentrations. However, because of its synergistic interactions with azole antifungals, polymyxin B at much lower concentrations exerts a potent fungicidal effect against Cryptococcus neoformans, Candida albicans and non-albicans Candida species and moulds when combined with azoles. The combination of polymyxin B and fluconazole at concentrations within susceptible breakpoints is particularly potent against C. neoformans isolates, including fluconazole-resistant strains. The drug combination displayed no additional toxicity compared with polymyxin B alone when tested in cell culture.

CONCLUSIONS

The combination of polymyxin B and fluconazole has the potential to be used in the clinic to treat systemic cryptococcosis. Our findings suggest that combining cationic peptide antibiotics with azole antifungals could provide a new direction for developing novel antifungal therapies.

Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the infectious diseases society of america

Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. These guidelines for its management have been built on the previous Infectious Diseases Society of America guidelines from 2000 and include new sections. There is a discussion of the management of cryptococcal meningoencephalitis in 3 risk groups: (1) human immunodeficiency virus (HIV)-infected individuals, (2) organ transplant recipients, and (3) non-HIV-infected and nontransplant hosts. There are specific recommendations for other unique risk populations, such as children, pregnant women, persons in resource-limited environments, and those with Cryptococcus gattii infection. Recommendations for management also include other sites of infection, including strategies for pulmonary cryptococcosis. Emphasis has been placed on potential complications in management of cryptococcal infection, including increased intracranial pressure, immune reconstitution inflammatory syndrome (IRIS), drug resistance, and cryptococcomas. Three key management principles have been articulated: (1) induction therapy for meningoencephalitis using fungicidal regimens, such as a polyene and flucytosine, followed by suppressive regimens using fluconazole; (2) importance of early recognition and treatment of increased intracranial pressure and/or IRIS; and (3) the use of lipid formulations of amphotericin B regimens in patients with renal impairment. Cryptococcosis remains a challenging management issue, with little new drug development or recent definitive studies. However, if the diagnosis is made early, if clinicians adhere to the basic principles of these guidelines, and if the underlying disease is controlled, then cryptococcosis can be managed successfully in the vast majority of patients.

Clinical pharmacokinetics of oral controlled-release 5-fluorocytosine

5-Fluorocytosine (5FC) is an oral antifungal that is currently used in combination with amphotericin B to treat Cryptococcus neoformans meningoencephalitis. The oral dosing of 5FC could be optimized by the use of a controlled-release (CR) formulation. The objective of the current study was to develop two prototype 5FC-CR formulations and evaluate the single-dose (1,500-mg) serum pharmacokinetic profiles of those formulations relative to the profile of the commercially available, immediate-release 5FC product (Ancobon) by the use of a phase 1, open-label, randomized, three-phase, crossover pharmacokinetic study design. Hydroxypropyl methylcellulose was utilized as the rate-controlling matrix to compound the 5FC-CR tablets. The two prototype 5FC-CR formulations demonstrated 80% release at 13.0 and 18.4 h, respectively, whereas the immediate-release product demonstrated 80% release at 0.28 h, as determined in vitro by the United States Pharmacopeia apparatus 2 dissolution method. Five subjects completed all three phases of the study without any adverse events. The mean maximum concentration, the area under the curve from time zero to 24 h, and the area under the curve from time zero to infinity were approximately 50% lower (P < 0.01) with the 5FC-CR formulations than with the immediate-release 5FC product. However, no statistically significant differences in the minimum concentrations at 24 h were noted between the formulations. The gastric absorption profile of 5FC-CR was well predicted by in vitro dissolution. Future exploration of a gastroretentive 5FC-CR formulation could overcome the marked lack of bioequivalence observed in the present study.

Immune reconstitution disease: recent developments and implications for antiretroviral treatment in resource-limited settings

PURPOSE OF REVIEW

We review literature published over the past 2 years regarding the immunopathogenesis, epidemiology, clinical spectrum and outcomes of immune reconstitution disease in patients receiving antiretroviral treatment. Particular attention is drawn to data relevant to resource-limited settings.

RECENT FINDINGS

In high-income countries, immune reconstitution disease occurs in association with a largely predictable spectrum of pathogens, including the herpesviruses, Mycobacterium tuberculosis and Mycobacterium avium complex, Cryptococcus neoformans and hepatitis viruses. Dermatological manifestations are most frequent. In resource-limited settings, patients accessing antiretroviral treatment programmes typically have advanced immunodeficiency, which increases risk of immune reconstitution disease. M. tuberculosis and C. neoformans have emerged as the key causes of morbidity and mortality associated with immune reconstitution disease. An increasing number of 'tropical' infections, including leprosy, schistosomiasis, strongyloidiasis, leishmaniasis, histoplasmosis and many nontuberculous mycobacteria, are also now recognised to provoke immune reconstitution disease but the overall spectrum and relative importance of these organisms remain to be defined. Better characterisation of immune reconstitution disease in these settings is needed to enable development of guidelines regarding prevention, diagnosis and management.

SUMMARY

While immune reconstitution disease in high-income countries has been clinically and epidemiologically well described, much remains to be learned in resource-limited settings in which immune reconstitution disease is emerging as a significant cause of morbidity and mortality.

Pharmacotherapy of cryptococcosis

Cryptococcus neoformans is an opportunistic fungal pathogen that causes central nervous system and pulmonary disease among immunocompromised patients. Recent studies highlight the high incidence of cryptococcosis among patients in certain resource-poor areas, where there is also a high incidence of AIDS. Despite the availability of antifungal agents with anticryptococcal activity, the mortality and treatment-failure rates associated with cryptococcosis remain unacceptably high. This article reviews current treatment strategies and the basis for these strategies, as well as prospects for future approaches to the treatment of cryptococcosis.

Treatment of cryptococcal meningitis in resource limited settings

PURPOSE OF REVIEW

Cryptococcal meningitis most commonly occurs in advanced HIV. Although diminishing in the developed world with antiretroviral therapy (ART), it remains a major problem in resource-limited settings. ART rollout will improve long-term HIV survival if opportunistic infections are effectively treated. Considering cryptococcal meningitis in that context, this review addresses excess morbidity and mortality in developing countries, treatment in areas of limited drug availability and challenges posed by combined anticryptococcal and HIV therapy.

RECENT FINDINGS

From Early Fungicidal Activity (EFA) studies, amphotericin B-flucytosine is best induction therapy but often unavailable; high dose amphotericin B monotherapy may be feasible in some settings. Where fluconazole is the only option, higher doses are more fungicidal. Serum cryptococcal antigen testing may identify patients at highest disease risk and primary prophylaxis is effective; the clinical role of such interventions needs to be established. Timing of ART introduction remains controversial; early initiation risks Immune Reconstitution Disease (IRD) delays may increase mortality.

SUMMARY

Amphotericin B based treatment is appropriate where possible. More studies are needed to optimize fluconazole monotherapy doses. Other research priorities include management of raised intracranial pressure, appropriate ART initiation and IRD treatment. Studies should focus on developing countries where problems are greatest.

Management of patients with the immune reconstitution inflammatory syndrome

A significant proportion of patients present with the immune reconstitution inflammatory syndrome (IRIS) after commencing antiretroviral therapy (ART). This syndrome is most frequently associated with infective causes. The lack of evidence-based treatment guidelines poses challenges in the management of these patients. Alternative causes for deterioration should be excluded, and optimization of treatment for the underlying opportunistic infection is essential. In addition, anti-inflammatory or immunomodulatory therapy may be considered, particularly in severe cases. Corticosteroids, the only treatment for which clinical trial data exist (for treating paradoxical tuberculosis-associated IRIS), are the treatment most frequently used in IRIS. Limited anecdotal reports of benefit exist for other agents, including NSAIDs, pentoxifylline, montelukast, thalidomide, and hydroxychloroquine. Therapeutic procedures (eg, aspiration of pus collections) play an important role in some patients. Interruption of ART may be considered in life-threatening forms of IRIS.

[Human immunodeficiency virus and AIDS-associated immune reconstitution syndrome. State of the art]

Since the arrival of highly active antiretroviral therapy (HAART), immune reconstitution syndrome (IRS) has become an increasingly more frequent complication in patients with human immunodeficiency virus (HIV) infection. This article presents a review of the available evidence on this subject, indexed in MEDLINE-PUBMED, BVS-BIREME, and BioMed Central. The review covers the definition, epidemiology, classification, and diagnostic criteria related to IRS. In addition, the clinical particularities of the most frequent etiologies are described, and a proposal for a therapeutic approach is formulated. The prognosis and future implications of this syndrome in the epidemiology of some infectious illnesses in the HIV-positive population are included. Several unresolved aspects are mentioned, such as those related to the pathophysiology of the condition, use of biomarkers for the diagnosis, and the need for evidence-based therapeutic algorithms to enable standardization of treatment for these patients.

Heteroresistance to fluconazole in Cryptococcus neoformans is intrinsic and associated with virulence

In 1999, heteroresistance to triazoles was reported in Cryptococcus neoformans strains isolated from an azole therapy failure case of cryptococcosis in an AIDS patient and in a diagnostic strain from a non-AIDS patient. In this study, we analyzed 130 strains of C. neoformans isolated from clinical and environmental sources before 1979, prior to the advent of triazoles, and 16 fluconazole (FLC)-resistant strains isolated from AIDS patients undergoing FLC maintenance therapy during 1990 to 2000. All strains isolated prior to 1979 manifested heteroresistance (subset of a population that grows in the presence of FLC) at concentrations between 4 and 64 microg/ml, and all 16 FLC-resistant AIDS isolates manifested heteroresistance at concentrations between 16 and 128 microg/ml. Upon exposure to stepwise increases in the concentration of FLC, subpopulations that could grow at higher concentrations emerged. Repeated transfer on drug-free media caused the highly resistant subpopulations to revert to the original level of heteroresistance. The reversion pattern fell into four categories based on the number of transfers required. The strains heteroresistant at > or =32 microg/ml were significantly more resistant to other xenobiotics and were also more virulent in mice than were those heteroresistant at < or =8 microg/ml. During FLC treatment of mice infected by strains with low levels of heteroresistance, subpopulations exhibiting higher levels of heteroresistance emerged after a certain period of time. The ABC transporter AFR1, known to efflux FLC, was unrelated to the heteroresistance mechanism. Our study showed that heteroresistance to azole is universal and suggests that heteroresistance contributes to relapse of cryptococcosis during azole maintenance therapy.

Novel relationship between tuberculosis immune reconstitution inflammatory syndrome and antitubercular drug resistance

BACKGROUND

Tuberculosis (TB) immune reconstitution inflammatory syndrome (IRIS) is emerging as an important early complication of combination antiretroviral therapy in patients with TB in developing countries. The differential diagnosis of TB IRIS includes deterioration caused by other human immunodeficiency virus-related morbidities and drug-resistant TB.

METHODS

We prospectively evaluated consecutive patients with suspected TB IRIS from February 2005 through July 2006 at a community-based secondary hospital in Cape Town, South Africa, by means of clinical case definitions for TB IRIS. Specimens were sent for TB culture and susceptibility testing, and a rapid test (FASTplaque-Response) was performed to expedite determination of rifampin susceptibility.

RESULTS

One hundred patients with suspected TB IRIS were evaluated, 26 of whom were being retreated for TB. IRIS symptoms developed a median of 14 days (interquartile range, 7-25 days) after the initiation of combination antiretroviral therapy. In 7 patients, an alternative opportunistic disease was diagnosed. Rifampin-resistant TB was present in 13 patients, 9 of whom received a diagnosis after study entry (7 of 9 had multidrug-resistant TB). Undiagnosed rifampin-resistant TB was thus present in 10.1% of patients (95% confidence interval, 3.9%-16.4%) who presented with TB IRIS, once those with alternative diagnoses and TB with known rifampin resistance were excluded. In the remaining 80 patients, TB IRIS without rifampin resistance was the final diagnosis.

CONCLUSIONS

TB IRIS that is clinically indistinguishable from TB IRIS that occurs in the context of drug-susceptible disease may occur in patients with undiagnosed multidrug-resistant TB. Antitubercular drug resistance should be excluded in all cases of suspected TB IRIS, and corticosteroids should be used with caution for patients with presumed TB IRIS until the result of drug-susceptibility testing is known.

Pharmacotherapy of yeast infections

The rise of immunocompromised individuals in our society has provoked a significant emergence in the number of patients affected by opportunistic pathogenic yeast. The microorganisms with a major clinical incidence are species from the genera Candida (especially Candida albicans) and Cryptococcus (particularly Cryptococcus neoformans), although there has been a significant increase in other pathogenic yeasts, such as Trichosporon spp. and Rhodotorula spp. In addition, there are an increasing number of patients infected by yeasts that were not previously considered as pathogenic, such as Saccharomyces cerevisiae. The management of these infections is complicated and is highly dependent on the susceptibility profile not only of the species but also of the strain. The available antifungal compounds belong mainly to the polyene, azole and candin families, which show a distinct spectrum of activity. This review summarizes the current knowledge about the use of the main antifungals for treating infections caused by the yeast species with the most significant clinical relevance, including the susceptibility profiles exhibited by these species in vitro.

Dose response effect of high-dose fluconazole for HIV-associated cryptococcal meningitis in southwestern Uganda

BACKGROUND

Therapy for human immunodeficiency virus (HIV)-associated cryptococcal meningitis in many centers in Africa is fluconazole administered at a dosage of 400-800 mg per day. However, higher dosages of fluconazole have been used to treat patients without resulting in serious toxicity. Pharmacokinetic and pharmacodynamic considerations suggest that higher dosages might be associated with greater efficacy.

METHODS

Sixty HIV-seropositive, antiretroviral therapy-naive patients with first-episode cryptococcal meningitis in Mbarara, Uganda, were treated with fluconazole: the first 30 patients received 800 mg per day, and the second 30 patients received 1200 mg per day. After 2 weeks, the dosage was reduced to 400 mg per day for an additional 8 weeks. The primary outcome measure was rate of clearance of infection, or early fungicidal activity, as determined by serial quantitative cerebrospinal fluid cryptococcal cultures during the first 2 weeks. Secondary outcome measures were safety and mortality through 10 weeks.

RESULTS

Forty-seven percent of patients had a reduced level of consciousness at presentation. Early fungicidal activity was significantly greater for patients receiving fluconazole at a dosage of 1200 mg per day than it was for patients receiving 800 mg per day (early fungicidal activity +/- standard deviation, -0.18+/-0.11 vs. -0.07+/-0.17 log colony-forming units/mL per day; P=.007). Fluconazole administered at a dosage of 1200 mg per day appeared to be well tolerated, and no liver function disturbance was observed. Two-week and 10-week mortality were 30% and 54%, respectively, with no statistically significant difference between the groups.

CONCLUSIONS

Fluconazole is more rapidly fungicidal when administered at a dosage of 1200 mg per day than when administered at a dosage of 800 mg per day. In resource-limited settings, additional studies are needed to test the addition of flucytosine or short-duration amphotericin B to high-dose fluconazole and to test strategies to facilitate earlier presentation, diagnosis, and treatment of patients with cryptococcal meningitis.

Managing cryptococcosis in the immunocompromised host

PURPOSE OF REVIEW

Expanding access to antiretroviral treatment has dramatically improved the long-term prognosis of patients with HIV-associated cryptococcal disease who survive the acute infection. However, the incidence and acute mortality of HIV-associated cryptococcal meningitis remain high. In this context, this review summarizes urgently needed recent work aimed at improving the acute management of cryptococcal infection in immunocompromised hosts.

RECENT FINDINGS

Studies have started to optimize antifungal regimens and address the complications of raised cerebrospinal fluid pressure and cryptococcal immune reconstitution syndrome. Amphotericin B at 1 mg/kg per day has been shown to be more rapidly fungicidal than the standard dose of 0.7 mg/kg per day, and new data support the importance of combination therapy with flucytosine. Amphotericin B and fluconazole at 800 mg is an alternative combination that appears superior to amphotericin B alone. At a dosage of 400 mg per day, fluconazole alone is much less rapidly fungicidal than amphotericin B and is associated with the development of secondary resistance.

SUMMARY

Recent findings support the use of rapidly fungicidal initial antifungal therapy with amphotericin B-based combination treatment. Where amphotericin B treatment is not yet feasible, studies are needed to optimize oral regimens. Based on accumulating data on rate of clearance of infection, the most promising new regimens in terms of fungicidal activity and safety could be selected for clinical endpoint trials.

Results from the ARTEMIS DISK Global Antifungal Surveillance Study, 1997 to 2007: 10.5-year analysis of susceptibilities of noncandidal yeast species to fluconazole and voriconazole determined by CLSI standardized disk diffusion testing

Fluconazole in vitro susceptibility test results determined by the CLSI M44-A disk diffusion method for 11,240 isolates of noncandidal yeasts were collected from 134 study sites in 40 countries from June 1997 through December 2007. Data were collected for 8,717 yeast isolates tested with voriconazole from 2001 through 2007. A total of 22 different species/organism groups were isolated, of which Cryptococcus neoformans was the most common (31.2% of all isolates). Overall, Cryptococcus (32.9%), Saccharomyces (11.7%), Trichosporon (10.6%), and Rhodotorula (4.1%) were the most commonly identified genera. The overall percentages of isolates in each category (susceptible, susceptible dose dependent, and resistant) were 78.0%, 9.5%, and 12.5% and 92.7%, 2.3%, and 5.0% for fluconazole and voriconazole, respectively. Less than 30% of fluconazole-resistant isolates of Cryptococcus spp., Cryptococcus albidus, Cryptococcus laurentii, Trichosporon beigelii/Trichosporon cutaneum, Rhodotorula spp., Rhodotorula rubra/Rhodotorula mucilaginosa, and Rhodotorula glutinis remained susceptible to voriconazole. Emerging resistance to fluconazole was documented among isolates of C. neoformans from the Asia-Pacific, Africa/Middle East, and Latin American regions but not among isolates from Europe or North America. This survey documents the continuing broad spectrum of activity of voriconazole against opportunistic yeast pathogens but identifies several of the less common species with decreased azole susceptibility. These organisms may pose a future threat to optimal antifungal therapy and emphasize the importance of prompt and accurate species identification.

Early mortality among adults accessing antiretroviral treatment programmes in sub-Saharan Africa

Two-thirds of the world's HIV-infected people live in sub-Saharan Africa, and more than 1.5 million of them die annually. As access to antiretroviral treatment has expanded within the region; early pessimism concerning the delivery of antiretroviral treatment using a large-scale public health approach has, at least in the short term, proved to be broadly unfounded. Immunological and virological responses to ART are similar to responses in patients treated in high-income countries. Despite this, however, early mortality rates in sub-Saharan Africa are very high; between 8 and 26% of patients die in the first year of antiretroviral treatment, with most deaths occurring in the first few months. Patients typically access antiretroviral treatment with advanced symptomatic disease, and mortality is strongly associated with baseline CD4 cell count less than 50 cells/mul and WHO stage 4 disease (AIDS). Although data are limited, leading causes of death appear to be tuberculosis, acute sepsis, cryptococcal meningitis, malignancy and wasting syndrome. Mortality rates are likely to depend not only on the care delivered by antiretroviral treatment programmes, but more fundamentally on how advanced disease is at programme enrollment and the quality of preceding healthcare. In addition to improving delivery of antiretroviral treatment and providing it free of charge to the patient, strategies to reduce mortality must include earlier diagnosis of HIV infection, strengthening of longitudinal HIV care and timely initiation of antiretroviral treatment. Health systems delays in antiretroviral treatment initiation must be minimized, especially in patients who present with advanced immunodeficiency.

Biomarkers of HIV Immune Reconstitution Inflammatory Syndrome

Dysregulation of the immune system drives HIV pathogenesis. As we develop new ways to treat HIV and AIDS, we encounter new clinical ramifications of our treatment on regulatory components of the immune system. HIV-associated Immune Reconstitution Inflammatory Syndrome (IRIS) occurs after initiation of anti-retroviral therapy (ART) with inappropriate and dysbalanced restoration of the immune system resulting in pathologic inflammatory reactions with significant morbidity. IRIS is most commonly associated with latent, occult, or past infections, including tuberculosis, Cryptococcus neoformans, and Mycobacterium avium-complex. We discuss common clinical presentations, new diagnostic modalities, current hypotheses of IRIS pathogenesis, and future directions of IRIS-related research, focusing on the identification of biomarkers that can be used to predict and diagnose IRIS.

Fungal brain infections

PURPOSE OF REVIEW

Fungal infections of the central nervous system, once a relatively rare occurrence, are increasingly common due to the expansion of immunocompromised populations at risk, and therefore are important to recognize early and manage appropriately.

RECENT FINDINGS

The specific infectious risk posed by novel immune-modifying therapies can, in most cases, be predicted on the basis of the immune target and medication timing. In addition, major advances in noninvasive diagnostic tests (e.g. serum beta glucan and galactomannan assays), and the recent introduction of more effective antifungal therapies, have led to a dramatic improvement in clinical outcomes.

SUMMARY

The current review provides approaches to patients with suspected central nervous system fungal infections based on host-risk factors, clinical syndromes and specific pathogens.

Capsule enlargement in Cryptococcus neoformans confers resistance to oxidative stress suggesting a mechanism for intracellular survival

Cryptococcus neoformans is a facultative intracellular pathogen. The most distinctive feature of C. neoformans is a polysaccharide capsule that enlarges depending on environmental stimuli. The mechanism by which C. neoformans avoids killing during phagocytosis is unknown. We hypothesized that capsule growth conferred resistance to microbicidal molecules produced by the host during infection, particularly during phagocytosis. We observed that capsule enlargement conferred resistance to reactive oxygen species produced by H(2)O(2) that was not associated with a higher catalase activity, suggesting a new function for the capsule as a scavenger of reactive oxidative intermediates. Soluble capsular polysaccharide protected C. neoformans and Saccharomyces cerevisiae from killing by H(2)O(2). Acapsular mutants had higher susceptibility to free radicals. Capsular polysaccharide acted as an antioxidant in the nitroblue tetrazolium (NBT) reduction coupled to beta-nicotinamide adenine dinucleotide (NADH)/phenazine methosulfate (PMS) assay. Capsule enlargement conferred resistance to antimicrobial peptides and the antifungal drug Amphotericin B. Interestingly, the capsule had no effect on susceptibility to azoles and increased susceptibility to fluconazole. Capsule enlargement reduced phagocytosis by environmental predators, although we also noticed that in this system, starvation of C. neoformans cells produced resistance to phagocytosis. Our results suggest that capsular enlargement is a mechanism that enhances C. neoformans survival when ingested by phagocytic cells.

Immune reconstitution inflammatory syndrome in HIV-infected patients receiving antiretroviral therapy : pathogenesis, clinical manifestations and management

The use of antiretroviral therapy (ART) to treat HIV infection, by restoring CD4+ cell count and immune function, is associated with significant reductions in morbidity and mortality. Soon after ART initiation, there is a rapid phase of restoration of pathogen-specific immunity. In certain patients, this results in inflammatory responses that may result in clinical deterioration known as 'the immune reconstitution inflammatory syndrome' (IRIS). IRIS may be targeted at viable infective antigens, dead or dying infective antigens, host antigens, tumour antigens and other antigens, giving rise to a heterogeneous range of clinical manifestations. The commonest forms of IRIS are associated with mycobacterial infections, fungi and herpes viruses. In most patients, ART should be continued and treatment for the associated condition optimized, and there is anecdotal evidence for the use of corticosteroids in patients who are severely affected. In this review, we discuss research relating to pathogenesis, the range of clinical manifestations, treatment options and prevention issues.

Cryptococcal meningitis manifesting as a large abdominal cyst in a HIV-infected patient with a CD4 count greater than 400 cells/mm(3)

Cryptococcal meningitis usually occurs among HIV-positive patients with CD4 counts less than 100 cells/mm(3) and manifests as headaches, fevers, and mental status changes. We present an unusual case of cryptococcal meningitis in a 34-year-old HIV-positive man presenting as a large abdominal cyst at the ventriculoperitoneal shunt site despite receiving highly active antiretroviral therapy (HAART) for more than 5 years and having a CD4 count more than 400 cells/mm(3).