HIV-associated cryptococcal meningitis

Overexpression of beta-arrestin 2 in peripheral blood mononuclear cells of patients with cryptococcal meningitis

Cryptococcal meningitis is often associated with elevated IL-10 levels, which suggest a dysregulation in the antifungal immune response. beta-Arrestin 2 plays a major role in desensitization of G-protein-coupled receptors involved in the immune responses, provides a scaffolding platform for modification of many signal transduction proteins, and binds Src and MAP kinases family members. This study compared the levels of beta-arrestin 2 mRNA and protein in peripheral blood mononuclear cells (PBMC) of patients with cryptococcal meningitis detected. The interferon-gamma (IFN-gamma) serum concentration was determined with enzyme-linked immunosorbent assay (ELISA) to reveal its relationship with beta-arrestin 2. The effect of modulation of beta-arrestin 2 on cytotoxic activity against Cryptococcus was explored via transfection and interference of beta-arrestin 2. PBMCs of patients with cryptococcal meningitis exhibited significantly elevated levels of beta-arrestin 2 and a positive correlation between beta-arrestin 2 and IL-10 levels existed in patients' serum, but a negative correlation was found between beta-arrestin 2 and IFN-gamma expression. In conclusion, elevated expression of beta-arrestin 2 in PBMCs of patients with cryptococcal meningitis correlated with a reduced cytotoxic activity against Cryptococcus. This study suggests that reduced beta-arrestin 2 mRNA levels or inhibition of beta-arrestin 2 activity may augment INF-gamma production, and ultimately, the anti-Cryptococcus immune response of infected patients.

Cost-effectiveness of serum cryptococcal antigen screening to prevent deaths among HIV-infected persons with a CD4+ cell count < or = 100 cells/microL who start HIV therapy in resource-limited settings

BACKGROUND

Cryptococcal meningitis (CM) remains a common AIDS-defining illness in Africa and Asia. Subclinical cryptococcal antigenemia is frequently unmasked with antiretroviral therapy (ART). We sought to define the cost-effectiveness of serum cryptococcal antigen (CRAG) screening to identify persons with subclinical cryptococcosis and the efficacy of preemptive fluconazole therapy.

METHODS

There were 609 ART-naive adults with AIDS who started ART in Kampala, Uganda, and who had a serum CRAG prospectively measured during 2004-2006. The number needed to test and treat with a positive CRAG was assessed for > or = 30-month outcomes.

RESULTS

In the overall cohort, 50 persons (8.2%) were serum CRAG positive when starting ART. Of 295 people with a CD4(+) cell count < or = 100 cells/microL and without prior CM, 26 (8.8%; 95% confidence interval [CI], 5.8%-12.6%) were CRAG positive, of whom 21 were promptly treated with fluconazole (200-400 mg) for 2-4 weeks. Clinical CM developed in 3 fluconazole-treated persons, and 30-month survival was 71% (95% CI, 48%-89%). In the 5 CRAG-positive persons with a CD4(+) cell count < or = 100 cells/microL treated with ART but not fluconazole, all died within 2 months of ART initiation. The number needed to test and treat with CRAG screening and fluconazole to prevent 1 CM case is 11.3 (95% CI, 7.9-17.1) at costs of $190 (95% CI, $132-$287). The number needed to test and treat to save 1 life is 15.9 (95% CI, 11.1-24.0) at costs of $266 (95% CI, $185-$402). The cost per disability-adjusted life year saved is $21 (95% CI, $15-$32).

CONCLUSIONS

Integrating CRAG screening into HIV care, specifically targeting people with severe immunosuppression (CD4(+) cell count < or = 100 cells/microL) should be implemented in treatment programs in resource-limited settings. ART alone is insufficient treatment for CRAG-positive persons.

Utility of clinical assessment, imaging, and cryptococcal antigen titer to predict AIDS-related complicated forms of cryptococcal meningitis

BACKGROUND

This study aimed to evaluate the prevalence and predictors of AIDS-related complicated cryptococcal meningitis. The outcome was complicated cryptococcal meningitis: prolonged (>/= 14 days) altered mental status, persistent (>/= 14 days) focal neurologic findings, cerebrospinal fluid (CSF) shunt placement or death. Predictor variable operating characteristics were estimated using receiver operating characteristic curve (ROC) analysis. Multivariate analysis identified independent predictors of the outcome.

RESULTS

From 1990-2009, 82 patients with first episode of cryptococcal meningitis were identified. Of these, 14 (17%) met criteria for complicated forms of cryptococcal meningitis (prolonged altered mental status 6, persistent focal neurologic findings 7, CSF surgical shunt placement 8, and death 5). Patients with complicated cryptococcal meningitis had higher frequency of baseline focal neurological findings, head computed tomography (CT) abnormalities, mean CSF opening pressure, and cryptococcal antigen (CRAG) titers in serum and CSF. ROC area of log2 serum and CSF CRAG titers to predict complicated forms of cryptococcal meningitis were comparable, 0.78 (95%CI: 0.66 to 0.90) vs. 0.78 (95% CI: 0.67 to 0.89), respectively (chi2, p = 0.95). The ROC areas to predict the outcomes were similar for CSF pressure and CSF CRAG titers. In a multiple logistic regression model, the following were significant predictors of the outcome: baseline focal neurologic findings, head CT abnormalities and log2 CSF CRAG titer.

CONCLUSIONS

During initial clinical evaluation, a focal neurologic exam, abnormal head CT and large cryptococcal burden measured by CRAG titer are associated with the outcome of complicated cryptococcal meningitis following 2 weeks from antifungal therapy initiation.

Immune reconstitution inflammatory syndrome (IRIS) associated with Cryptococcus neoformans infection in AIDS patients

Cryptococcosis is frequently associated to the immune reconstitution inflammatory syndrome (IRIS) in AIDS patients on highly active antiretroviral therapy (HAART). This study aimed to evaluate clinical and evolutive features of IRIS associated cryptococcosis patients in Uberaba, Brazil.

PATIENTS

Eighty-one AIDS individuals admitted at the teaching hospital with cryptococcal meningitis were evaluated and from these, 40 were prospectively followed. Of 40 patients with cryptococcosis, nine (22.5%) presented clinical and laboratory features of IRIS. Six (66.6%) were male, with a mean age of 37.2. Five (55.5%) presented cryptococcosis as first AIDS defining condition. In seven (77.9%) IRIS was characterised as a relapse of meningeal symptoms after 10 weeks, mean time of 72 days, of starting HAART whereas, two asymptomatic patients developed the syndrome as an unmasked cryptococcosis after 10 and 12 weeks on HAART. Lymphadenitis as isolated finding associated with IRIS was evidenced in three cases. All patients presented low CD4(+) and high RNA viral load baseline values. Cultures of cerebrospinal fluid and lymph-node fragments tissues of these cases were negative. Six of nine individuals developed high intracranial pressure requiring a daily relief lumbar puncture. No deaths occurred during the evolution of these patients. The incidence and clinical evolutive profile observed in this case series are in accordance with other reports elsewhere.

Small animal zoonoses and immuncompromised pet owners

This review is a general discussion of common zoonotic infections of companion animals in the United States. Microbes, routes of transmission, and risks to immunocompromised persons are discussed. The primary focus of this article is dogs and cats, although zoonoses of avian, rodent, and rabbit companion animals are discussed in brief. An awareness of zoonoses will allow veterinarians and physicians to collaboratively prevent transmission and treat clinical disease in both human and veterinary patients.

Is HIV-associated tuberculosis a risk factor for the development of cryptococcal disease?

Cryptococcal meningitis and tuberculosis are leading causes of mortality in patients initiating antiretroviral therapy in Africa. We hypothesized that a history of tuberculosis may predispose to the development of cryptococcal meningitis and examined the association using multivariate logistic regression in a cohort of patients initiating antiretroviral therapy. History of pulmonary tuberculosis was independently associated with the development of cryptococcal meningitis (odds ratio = 6.6; 95% confidence interval = 1.3-32.7) after adjustment for covariates, including CD4 cell counts. A number of potential mechanisms may underlie this association.

Neurologic presentations of AIDS

The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurred an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome).

Treatment of cryptococcal meningitis in KwaZulu-Natal, South Africa

Background

Cryptococcal meningitis (CM) remains a leading cause of death for HIV-infected individuals in sub-Saharan Africa. Improved treatment strategies are needed if individuals are to benefit from the increasing availability of antiretroviral therapy. We investigated the factors associated with mortality in routine care in KwaZulu-Natal, South Africa.

Methodology/Principal Findings

A prospective year long, single-center, consecutive case series of individuals diagnosed with cryptococcal meningitis 190 patients were diagnosed with culture positive cryptococcal meningitis, of whom 186 were included in the study. 52/186 (28.0%) patients died within 14 days of diagnosis and 60/186 (32.3%) had died by day 28. In multivariable cox regression analysis, focal neurology (aHR 11 95%C.I. 3.08–39.3, P<0.001), diastolic blood pressure <60 mmHg (aHR 2.37 95%C.I. 1.11–5.04, P = 0.025), concurrent treatment for tuberculosis (aHR 2.11 95%C.I. 1.02–4.35, P = 0.044) and use of fluconazole monotherapy (aHR 3.69 95% C.I. 1.74–7.85, P<0.001) were associated with increased mortality at 14 and 28 days.

Conclusions

Even in a setting where amphotericin B is available, mortality from cryptococcal meningitis in this setting is high, particularly in the immediate period after diagnosis. This highlights the still unmet need not only for earlier diagnosis of HIV and timely access to treatment of opportunistic infections, but for better treatment strategies of cryptococcal meningitis.

Monitoring and impact of fluconazole serum and cerebrospinal fluid concentration in HIV-associated cryptococcal meningitis-infected patients

OBJECTIVES

The aim of the present study was to assess fluconazole pharmacokinetic measures in serum and cerebrospinal fluid (CSF); and the correlation of these measures with clinical outcomes of invasive fungal infections.

METHODS

A randomized trial was conducted in HIV-infected patients receiving three different regimens of fluconazole plus amphotericin B (AmB) for the treatment of cryptococcal meningitis. Regimens included fluconazole 400 mg/day+AmB (AmB+Fluc400) or fluconazole 800 mg/day+AmB (AmB+Fluc800) (14 days followed by fluconazole alone at the randomized dose for 56 days); or AmB alone for 14 days followed by fluconazole 400 mg/day for 56 days. Serum (at 24 h after dosing) and CSF samples were taken at baseline and days 14 and 70 (serum only) for fluconazole measurement, using gas-liquid chromatography.

RESULTS

Sixty-four treated patients had fluconazole measurements: 11 in the AmB group, 12 in the AmB+Fluc400 group and 41 in the AmB+Fluc800 group. Day 14 serum concentration geometric means were 24.7 mg/L for AmB+Fluc400 and 37.0 mg/L for AmB+Fluc800. Correspondingly, CSF concentration geometric means were 25.1 mg/L and 32.7 mg/L. Day 14 Serum and CSF concentrations were highly correlated with AmB+Fluc800 (P<0.001, r=0.873) and AmB+Fluc400 (P=0.005, r=0.943). Increased serum area under the curve (AUC) appears to be associated with decreased mortality at day 70 (P=0.061, odds ratio=2.19) as well as with increased study composite endpoint success at days 42 and 70 (P=0.081, odds ratio=2.25 and 0.058, 2.89, respectively).

CONCLUSION

High fluconazole dosage (800 mg/day) for the treatment of HIV-associated cryptococcal meningitis was associated with high serum and CSF fluconazole concentration. Overall, high serum and CSF concentration appear to be associated with increased survival and primary composite endpoint success.

Micoses sistêmicas: fatores associados ao óbito em pacientes com infecção pelo vírus da imunodeficiência humana, Cuiabá, Estado de Mato Grosso, 2005-2008

A prevalência de micose sistêmica entre 1.300 pacientes portadores de HIV/Aids de Cuiabá, Mato Grosso foi de 4,6%, no período de 2005-2008. As espécies de fungos isoladas foram o Cryptococcus neoformans (50%), Cryptococcus gattii (1,6%), Cryptococcus spp (6,6%), Histoplasma capsulatum (38,3%) e Paracoccidioides brasiliensis (3,3%). Óbito foi registrado em 32 (53,3%) pacientes, sendo a criptococose a principal causa. A contagem de linfócitos T CD4+ foi baixa e semelhante entre os pacientes que sobreviveram ou faleceram por micose sistêmica. O etilismo (OR:8,2; IC95%: 1,4-62,1; p=0,005) e o nível médio de desidrogenase lática [758 (182) U/L vs 416 (268) U/L; p<0,001] foram as características independentemente associadas ao óbito dos pacientes do estudo. Os resultados mostram alta letalidade por micoses sistêmicas em pacientes portadores de HIV/Aids de Cuiabá e sugerem que características clínico-laboratoriais tais como o etilismo e a elevação precoce da desidrogenase lática podem ser fatores relacionados ao pior prognóstico nessas condições.

BLyS and APRIL expression in peripheral blood mononuclear cells of cryptococcal meningitis patients and their clinical significance

OBJECTIVE

To investigate the levels of APRIL, BlyS and receptors as TACI, BCMA and BAFF-R in peripheral blood mononuclear cells (PBMC) of cryptococcal meningitis (CM) patients and its clinical significance.

METHODS

PBMC from 30 CM patients and 32 healthy controls were isolated. The mRNA levels of APRIL, BLyS and BLyS receptors were detected by fluorescent quantitation PCR. The effect of PBMC from CM patients on in vitro growth of Cryptococcus neoformans was compared in presence and absence of BLyS.

RESULTS

PBMC of CM patients exhibited significantly lower BLyS, TACI and BCMA mRNA levels but significantly higher BAFF-R mRNA levels than controls. Growth of C. neoformans was significantly slower in presence of BLyS than its absence.

CONCLUSION

Levels of BlyS and its receptors correlated with cryptococcal meningitis progression, and provide new clues for monitoring CM conditions and its effective therapy.

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.

Colitis as a manifestation of infliximab-associated disseminated cryptococcosis

The ability of tumor necrosis factor (TNF)-alpha inhibitors to impair pivotal pro-inflammatory host defenses may facilitate the development of disseminated cryptococcosis. Gastrointestinal (GI) tract disease is an unusual presentation of this yeast infection. We describe a unique case of disseminated cryptococcosis presenting as colitis that mimicked an exacerbation of Crohn's disease in a TNF-alpha inhibitor recipient. Review of existing literature shows that in immunocompromised patients, GI cryptococcosis invariably coexists with disseminated cryptococcosis, often lacks prominent GI symptomatology, and is primarily diagnosed postmortem. In cases with opportunistic infections, discontinuation of TNF-alpha inhibitors is a common practice, however rapid rebound of inflammatory responses may incur the risk of immune reconstitution syndrome.

Long-Term Efficacy and Safety of TDM-Assisted Combination of Voriconazole plus Efavirenz in an AIDS Patient with Cryptococcosis and Liver Cirrhosis

Objective

To report the efficacy, tolerability, and pharmacokinetic effects of combined voriconazole and efavirenz treatment administered at therapeutic drug monitoring (TDM)–based adjusted doses to a patient with AIDS, cryptococcosis, and mild liver cirrhosis.

Case Summary

A 40-year-old man with AIDS (hemophiliac, antiretroviral-naïve, plasma HIV-RNA = 290,000 copies/mL, CD4+ lymphocytes = 0), hepatitis C virus–related liver cirrhosis (Child-Pugh class A), and cryptococcal meningitis was failing standard antifungal therapies. He received an antifungal–antiretroviral combination treatment based on the association of voriconazole plus efavirenz. Doses of both drugs were serially adjusted based on their plasma concentrations, which were evaluated at steady-state of each dose combination at least once (week 3.1 or later) as full concentration–time profile (samples collected at 0, 1, 2, 3, 4, 6, 8, 12 h postdose). Adequate concentrations of voriconazole in both plasma and cerebrospinal fluid were obtained and target plasma concentrations of efavirenz were achieved at the final dose adjustment (voriconazole 200 mg twice daily plus efavirenz 300 mg once daily, both administered orally). The patient showed prompt and stable suppression of cryptococcosis and plasma viremia of HIV at long-term follow-up (66 wk), with no significant adverse events.

Discussion

Standard therapies for cryptococcosis in patients with AIDS are often not effective. Voriconazole, despite its promising anticryptococcal efficacy, is currently not approved for cryptococcosis therapy in the US and Europe, nor is it recommended for combination with efavirenz due to the significant pharmacokinetic interactions between the 2 compounds. Thus far, published studies regarding the effects of voriconazole in human cryptococcosis are scarce and none has described the clinical and pharmacokinetic outcomes of a voriconazole/efavirenz combination in patients with AIDS, either with or without liver cirrhosis.

Conlusions

The combination of voriconazole and efavirenz at TDM-assisted doses may represent a valuable therapeutic option in AIDS patients with cryptococcosis and mild liver cirrhosis.

Risk factors for mortality from primary cryptococcosis in patients with HIV

Cryptococcosis continues to have a high mortality rate in human immunodeficiency virus (HIV)-positive patients despite advances made in antifungal treatment, intracranial pressure management, and antiretroviral therapy. This retrospective chart review was conducted at the University of Maryland Medical Center and Baltimore VA Medical Center from 1993 to 2004. We reviewed all inpatient cases of cryptococcal infections to assess predictors of inpatient mortality among HIV-positive patients. Data collected included patient demographics, presenting symptoms and CD4 counts, lumbar puncture (LP) results including opening pressure (OP), cryptococcal antigen (CAg) levels, sites of infection, and drug therapy. Multivariate and survival analyses were performed. We identified 202 patients with primary cryptococcosis. The main sites of infection included blood (72%), central nervous system (85%), and lower respiratory tract (34%). Overall 30-day mortality was 14%. Predictors of mortality included syncope (P = 0.039; OR, 4.5), concomitant pneumonia (P = 0.001; OR, 3.5), respiratory failure (P < 0.001; OR, 10.5), and admission into the intensive care unit (P < 0.001; OR, 8). Amphotericin dose, OP > or = 250 mm H2O, and number of LPs were not found to be predictive of mortality. Mortality attributable to cryptococcosis remains high. Our study findings suggest that syncope, respiratory failure, pneumonia, and admission to the intensive care unit are independently associated with an increased risk of death within 30 days after cryptococcosis diagnosis.

[Infections of the central nervous system in the immuno-compromised]

Infections of the central nervous system (CNS) can be caused by a variety of pathogens, depending on whether the number and function of T-cells or monocytes are impaired (as in HIV patients) or whether the number and function of polymorphonuclear granulocytes are reduced or impaired, as typically seen in patients on immunosuppressive therapy, post transplantation, etc.. The first part of the chapter deals with CNS infections associated with reduced or abnormal T-cell (or monocytic) function and number, mainly seen in HIV patients, such as cerebral toxoplasmosis, CNS cryptococcosis, cytomegalovirus encephalitis, and progressive multifocal leukoencephalopathy. The clinical presentation, diagnostic procedures, as well as therapeutic and prophylactic management of these diseases are described in detail. The second part of the chapter deals with diseases usually seen in patients with impaired or reduced number and function of polymorphonuclear granulocytes. Such CNS infections are frequently caused by viral, bacterial, or fungal pathogens and are described in their clinical presentation, their diagnostic procedures and the best possible therapeutic and prophylactic management.

Virulence in Cryptococcus species

Cryptococcus neoformans and Cryptococcus gattii are the cause of life-threatening meningoencephalitis in immunocompromised and immunocompetent individuals respectively. The increasing incidence of cryptococcal infection as a result of the AIDS epidemic, the recent emergence of a hypervirulent cryptococcal strain in Canada and the fact that mortality from cryptococcal disease remains high have stimulated intensive research into this organism. Here we outline recent advances in our understanding of C. neoformans and C. gattii, including intraspecific complexity, virulence factors, and key signaling pathways. We discuss the molecular basis of cryptococcal virulence and the interaction between these pathogens and the host immune system. Finally, we discuss future challenges in the study and treatment of cryptococcosis.

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.

Epidemiology, etiology, pathogenesis, and diagnosis of recurrent bacterial meningitis

Recurrent bacterial meningitis is a rare phenomenon and generally poses a considerable diagnostic challenge to the clinician. Ultimately, a structured approach and early diagnosis of any underlying pathology are crucial to prevent further episodes and improve the overall outcome for the affected individual. In this article, we are reviewing the existing literature on this topic over the last two decades, encompassing 363 cases of recurrent bacterial meningitis described in 144 publications. Of these cases, 214 (59%) were related to anatomical problems, 132 (36%) were related to immunodeficiencies, and 17 (5%) were related to parameningeal infections. The review includes a detailed discussion of the underlying pathologies and microbiological aspects as well as recommendations for appropriate diagnostic pathways for investigating this unusual entity.

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.