Physiological Differences in Cryptococcus neoformans Strains In Vitro versus In Vivo and Their Effects on Antifungal Susceptibility.

Cryptococcus neoformans is an environmentally ubiquitous fungal pathogen that primarily causes disease in people with compromised immune systems, particularly those with advanced AIDS. There are estimated to be almost 1 million cases per year of cryptococcal meningitis in patients infected with human immunodeficiency virus, leading to over 600,000 annual deaths, with a particular burden in sub-Saharan Africa. Amphotericin B (AMB) and fluconazole (FLC) are key components of cryptococcal meningitis treatment: AMB is used for induction, and FLC is for consolidation, maintenance and, for occasional individuals, prophylaxis. However, the results of standard antifungal susceptibility testing (AFST) for AMB and FLC do not correlate well with therapeutic outcomes and, consequently, no clinical breakpoints have been established. While a number of explanations for this absence of correlation have been proffered, one potential reason that has not been adequately explored is the possibility that the physiological differences between the in vivo infection environment and the in vitro AFST environment lead to disparate drug susceptibilities. These susceptibility-influencing factors include melanization, which does not occur during AFST, the size of the polysaccharide capsule, which is larger in infecting cells than in those grown under normal laboratory conditions, and the presence of large polyploid "titan cells," which rarely occur under laboratory conditions. Understanding whether and how C. neoformans differentially expresses mechanisms of resistance to AMB and FLC in the AFST environment compared to the in vivo environment could enhance our ability to interpret AFST results and possibly lead to the development of more applicable testing methods.

Laboratory methods for diagnostics of HIV infection and HIV-associated neuroinfections.

HIV Infection resulting in AIDS remains serious global public health problem. In the fight with the global health problem plays a key role a simple, reliable and fast diagnostics. An important method in diagnostics is the identification and detection of viral capside p24 antigen levels. Fourth generation tests for the diagnostics of HIV infection simultaneously detect the presence of HIV antibodies and p24 antigen. Based on the monitoring of CD4 count, we can estimate the stage in which the infection is, and we can also suggest a therapeutic approach. Cerebral toxoplasmosis is the most common neurological opportunistic disease manifested in HIV infected patients. Cryptococcal meningitis is the second most common cause of the opportunistic neuroinfections. Despite of significant advances in the diagnostics and treatment of HIV infection, this disease is still unable to get completely under control. The future perspective in HIV diagnostics are biosensors.

The effect of therapeutic lumbar punctures on acute mortality from cryptococcal meningitis.

INTRODUCTION: Cryptococcal meningitis is the most common cause of adult meningitis in sub-Saharan Africa. Raised intracranial pressure (ICP) is common in cryptococcosis. Prior studies suggest elevated ICP is associated with mortality, and guidelines recommend frequent lumbar punctures (LPs) to control ICP. However, the magnitude of the impact of LPs on cryptococcal-related mortality is unknown. METHODS: In sum, 248 individuals with human immunodeficiency virus (HIV)-associated cryptococcal meningitis, screened for the Cryptococcal Optimal ART Timing (COAT) trial in Uganda and South Africa, were observed. Individuals received an LP to diagnose meningitis, and subsequent therapeutic LPs were recommended for elevated ICP (>250 mmH2O) or new symptoms. We compared survival, through 11 days, between individuals receiving at least 1 therapeutic LP with individuals not receiving therapeutic LPs. The COAT trial randomized subjects at 7-11 days; thus, follow-up stopped at time of death, randomization, or 11 days. RESULTS: Seventy-five (30%) individuals had at least 1 therapeutic LP. Individuals receiving therapeutic LPs had higher cerebrospinal fluid (CSF) opening pressures, higher CSF fungal burdens, and were more likely to have altered mental status at baseline than those with no therapeutic LPs. Thirty-one deaths (18%) occurred among 173 individuals without a therapeutic LP and 5 deaths (7%) among 75 with at least 1 therapeutic LP. The adjusted relative risk of mortality was 0.31 (95% confidence interval: .12-.82). The association was observed regardless of opening pressure at baseline. CONCLUSIONS: Therapeutic LPs were associated with a 69% relative improvement in survival, regardless of initial intracranial pressure. The role of therapeutic LPs should be reevaluated.

Cryptococcosis in Colombian children and literature review.

Cryptococcosis is reported in adults and is often acquired immune deficiency syndrome (AIDS)-associated; however, its frequency in children is low. Based on the National Survey on Cryptococcosis conducted in Colombia, an epidemiological and clinical analysis was performed on cases of the disease observed in children less than 16 years old between 1993-2010. We found 41 affected children (2.6% prevalence) from the 1,578 surveys received. The country mean annual incidence rate was 0.017 cases/100,000 children under 16 years, while in Norte de Santander the incidence rate was 0.122 cases/100,000 (p < 0.0001). The average age of infected children was 8.4 and 58.5% were male. In 46.3% of cases, a risk factor was not identified, while 24.4% had AIDS. The most frequent clinical manifestations were headache (78.1%), fever (68.8%), nausea and vomiting (65.6%), confusion (50%) and meningeal signs (37.5%). Meningitis was the most frequent clinical presentation (87.8%). Amphotericin B was given to 93.5% of patients as an initial treatment. Positive microbiological identification was accomplished by India ink (94.7%), latex in cerebrospinal fluid (100%) and culture (89.5%). Out of 34 isolates studied, Cryptococcus neoformans var. grubii (VNI 85.3%, VNII 8.8%) was isolated in 94.1% of cases and Cryptococcus gattii (VGII) was isolated in 5.9% of cases. These data are complemented by a literature review, which overall suggests that cryptococcosis in children is an unusual event worldwide.

Quality of life of HIV-negative, previously healthy individuals following cryptococcal meningoencephalitis.

The morbidity and mortality of cryptococcal meningoencephalitis (CM) in previously healthy, HIV-negative individuals is increasingly recognized. We administered a healthcare associated quality of life (QOL) survey to the largest longitudinally followed cohort of these patients in the United States. We identified moderate or severe self-reported impairment in at least one QOL domain in 61% of subjects at least one year following diagnosis. Self-reported cognitive impairment was noted in 52% and sleep disturbance was noted in 55%. This is the first comprehensive study of cross-sectional long-term QOL in previously healthy patients following cryptococcal infection.

Differences in human immunodeficiency virus-1C viral load and drug resistance mutation between plasma and cerebrospinal fluid in patients with human immunodeficiency virus-associated cryptococcal meningitis in Botswana.

To determine effects of cryptococcal meningitis (CM) on human immunodeficiency virus (HIV)-1C cerebrospinal fluid (CSF) viral escape, CSF/plasma viral discordance, and drug resistance mutation (DRM) discordance between CSF and plasma compartments, we compared CSF and plasma viral load (VL) and DRMs in individuals with HIV-associated CM in Botswana.This cross-sectional study utilized 45 paired CSF/plasma samples from participants in a CM treatment trial (2014-2016). HIV-1 VL was determined and HIV-1 protease and reverse transcriptase genotyping performed. DRMs were determined using the Stanford HIV database. CSF viral escape was defined as HIV-1 ribonucleic acid ≥0.5 log10 higher in CSF than plasma and VL discordance as CSF VL > plasma VL.HIV-1 VL was successfully measured in 39/45 pairs, with insufficient sample volume in 6; 34/39 (87.2%) participants had detectable HIV-1 in plasma and CSF, median 5.1 (interquartile range: 4.7-5.7) and 4.6 (interquartile range:3.7-4.9) log10 copies/mL, respectively (P≤.001). CSF viral escape was present in 1/34 (2.9%) and VL discordance in 6/34 (17.6%). Discordance was not associated with CD4 count, antiretroviral status, fungal burden, CSF lymphocyte percentage nor mental status. Twenty-six of 45 (57.8%) CSF/plasma pairs were successfully sequenced. HIV-1 DRM discordance was found in 3/26 (11.5%); 1 had I84IT and another had M46MI in CSF only. The third had K101E in plasma and V106 M in CSF.Our findings suggest that HIV-1 escape and DRM discordance may occur at lower rates in participants with advanced HIV-disease and CM compared to those with HIV associated neurocognitive impairment.

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.

Lessons learned about opportunistic infections in southeast Asia.

Southeast Asia is a region where the number of people infected with HIV/AIDS is one of the fastest growing in the world. Tuberculosis (TB) has grown along with the HIV epidemic. TB is not only the most common AIDS-defining illness but is also the leading cause of morbidity and mortality in AIDS patients. Cryptococcosis (meningitis or disseminated) is one of the most common opportunistic infections in AIDS patients. Cryptococcal meningitis is the first in the differential diagnosis considered with meningeal irritation. Penicillosis, a unique systemic mycosis, is an important emerging public health problem and has been classified as an AIDS defining illness in endemic areas like Thailand. Pneumocystis carinii (jiroveci) pneumonia has been one of the most important opportunistic infections in AIDS patients. Among parasitic infections, cryptosporidiosis is the most common intestinal protozoan infection relating to diarrhea in AIDS patients and toxoplasmosis is the only parasitic infection of the nervous system with a substantial incidence, up to 14.8%. Cytomegalovirus (CMV) retinitis has a lower prevalence compared to other opportunistic infections. In the era of highly active antiretroviral therapy (HAART), the incidence of opportunistic infections has significantly reduced in the past few years. Subsequently, the phenomena of immune restoration inflammatory syndrome (IRIS) in AIDS patients has been reported in this region as a result of HAART.

Cryptococcal meningitis in an immunocompetent patient with obstructive hydrocephalus: A case report.

BACKGROUND: Cryptococcal infections of the central nervous system are very rare in immunocompetent patients. They usually present as meningitis or as fungal cysts with or without hydrocephalus. Rapid diagnosis and treatment is crucial to the prognosis. CASE REPORT: We report the case of an immunocompetent 40-year-old male patient with no medical or surgical history and no recent travel, who was hospitalized in our neurosurgery department because of a rapidly worsening headache. The neurological examination revealed no focal deficit but worrying signs of increased intracranial pressure. Magnetic resonance imaging (MRI) with contrast showed thick and large-scale cortico-pial cerebellar enhancements, associated with severe obstructive hydrocephalus. This required emergency endoscopic ventriculocisternostomy during which we observed cottony tissues along the ventricular walls. Biopsied tissues and cerebrospinal fluid samples (CSF) were not contributive. A CT scan of the chest and abdomen and blood markers of common primary tumors were all negative. No evidence of HIV infection or any cause of immunosuppression was identified. Symptoms and a second MRI slightly improved with intravenous corticosteroid therapy. The hypothesis of a lymphoma or granulomatous disease was made initially for which direct surgical biopsies were scheduled. The diagnosis of cryptococcal meningitis was obtained later on by simultaneous plasma and CSF Cryptococcus antigen detection. Cryptococcus neoformans (formerly C. neoformans var. grubii [serotype A]) was then identified by PCR. Clinical improvement was obtained with antifungal therapy. CONCLUSION: Cryptococcal meningitis is a well-known condition in immunocompromised patients, often causing hydrocephalus requiring neurosurgical management. The diagnosis is more difficult in patients with no history of HIV or organ transplant. Neurologists and neurosurgeons must consider this possibility in case of diffuse, thick leptomeningeal enhancement on MRI.

Factors influencing cerebrospinal fluid and plasma HIV-1 RNA detection rate in patients with and without opportunistic neurological disease during the HAART era.

BACKGROUND: In the central nervous system, HIV replication can occur relatively independent of systemic infection, and intrathecal replication of HIV-1 has been observed in patients with HIV-related and opportunistic neurological diseases. The clinical usefulness of HIV-1 RNA detection in the cerebrospinal fluid (CSF) of patients with opportunistic neurological diseases, or the effect of opportunistic diseases on CSF HIV levels in patients under HAART has not been well defined. We quantified CSF and plasma viral load in HIV-infected patients with and without different active opportunistic neurological diseases, determined the characteristics that led to a higher detection rate of HIV RNA in CSF, and compared these two compartments. METHODS: A prospective study was conducted on 90 HIV-infected patients submitted to lumbar puncture as part of a work-up for suspected neurological disease. Seventy-one patients had active neurological diseases while the remaining 19 did not. RESULTS: HIV-1 RNA was quantified in 90 CSF and 70 plasma samples. The HIV-1 RNA detection rate in CSF was higher in patients with neurological diseases, in those with a CD4 count lower than 200 cells/mm3, and in those not receiving antiretroviral therapy, as well as in patients with detectable plasma HIV-1 RNA. Median viral load was lower in CSF than in plasma in the total population, in patients without neurological diseases, and in patients with toxoplasmic encephalitis, while no significant difference between the two compartments was observed for patients with cryptococcal meningitis and HIV-associated dementia. CSF viral load was lower in patients with cryptococcal meningitis and neurotoxoplasmosis under HAART than in those not receiving HAART. CONCLUSION: Detection of HIV-1 RNA in CSF was more frequent in patients with neurological disease, a CD4 count lower than 200 cells/mm3 and detectable plasma HIV-1. Median HIV-1 RNA levels were generally lower in CSF than in plasma but some patients showed higher CSF levels, and no difference between these two compartments was observed in patients with cryptococcal meningitis and HIV-associated dementia, suggesting the presence of intrathecal viral replication in these patients. HAART played a role in the control of CSF HIV levels even in patients with cryptococcal meningitis and neurotoxoplasmosis in whom viral replication is potentially higher.

Outcome of AIDS-associated cryptococcal meningitis initially treated with 200 mg/day or 400 mg/day of fluconazole.

BACKGROUND: AIDS-associated cryptococcal meningitis has a high mortality. Fluconazole was the only systemic antifungal therapy available in our centre. From 1999-2001 we used low-dose fluconazole (200 mg daily initially), and did not offer therapy to patients perceived to have poor prognoses. In 2001 donated fluconazole became available, allowing us to use standard doses (400 mg daily initially). Antiretroviral therapy was not available during the study period. METHODS: Retrospective chart review of adult patients before and after the fluconazole donation. RESULTS: 205 patients fulfilled the inclusion criteria, 77 before and 128 after the donation. Following the donation fewer patients received no antifungal treatment (5% vs 19%, p = 0.002), and more patients received standard-dose fluconazole (90% vs 6%, p < 0.001). In-hospital mortality was 25%. Impaired consciousness, no antifungal treatment received and cerebrospinal fluid antigen titre > 1,000 were independent predictors of in-hospital mortality. Concomitant rifampicin did not affect in-hospital survival. Thirteen patients were referred to the tertiary referral hospital and received initial treatment with amphotericin B for a mean of 6 days - their in-hospital survival was not different from patients who received only fluconazole (p = 0.9). Kaplan-Meier analysis showed no differences in length of survival by initial treatment with standard or low doses of fluconazole (p = 0.27 log rank test); median survival was 76 and 82 days respectively. CONCLUSION: Outcome of AIDS-associated cryptococcal meningitis is similar with low or standard doses of fluconazole. The early mortality is high. Initial therapy with amphotericin B and other measures may be needed to improve outcome.

Primary and opportunistic pathogens associated with meningitis in adults in Bangui, Central African Republic, in relation to human immunodeficiency virus serostatus.

OBJECTIVE: To determine the causative organisms and characteristics of patients presenting with meningitis in Bangui in order to provide guidance to physicians for case management. METHODS: Adults with proven or suspected meningitis were enrolled in this prospective study. LABORATORY TESTS: Full blood count, blood chemistry, and HIV tests were performed. Cerebrospinal fluid (CSF) was submitted for routine microbiology, chemistry (glucose, protein), and hematology testing. When classical microbiology analyses were negative, a broad-range bacterial polymerase chain reaction (BRBPCR) was used. RESULTS AND CONCLUSIONS: Of the 276 patients enrolled, 215 (77.9%) were HIV positive. In HIV-positive patients cryptococcal meningitis (CM) was the most common cause of meningitis (39.1%) followed by pyogenic meningitis (PM) (30.7%), mononuclear meningitis (MM) (28.8%), and tuberculous meningitis (TM) (1.4%). In HIV-negative patients, PM was the most common cause (60.7%) followed by MM (37.7%) and CM (1.6%, one case). In-hospital mortality was higher in HIV-positive patients (73/128 = 57%) compared to those HIV negative (3/18 = 16.7%) (p = 0.001). Streptococcus pneumoniae (n = 26) was the most common bacterial diagnosis, mainly in HIV-positive patients (n = 22, 10.2%). Meningococcal meningitis (14 Neisseria meningitidis of group A and one W135) was diagnosed in nine (4.2%) HIV-positive and six (9.8%) HIV-negative patients. Gram-negative rods were isolated from five HIV-positive and two HIV-negative patients, respectively. The bacteria and fungi involved in meningitis did not display high levels of in vitro resistance. Conventional microbiology techniques failed to detect the causative agent in 55 (53.4%) PM cases. Broad-range bacterial PCR detected DNA from S. pneumoniae in three samples, N. meningitidis in two, Escherichia coli in one, Listeria monocytogenes in two and Staphylococcus aureus in one sample. In the CSF of five (three HIV negative and two HIV positive), PCR products were not identified with the oligonucleotide probes specific for the usual species of bacteria found in CSF, or genera commonly considered potential contaminants of clinical samples. Among the MM cases, 77 (90.5%) probable viral meningitis (54 HIV positive and 23 HIV negative) and eight TM (HIV positive) were suspected.

Update and New Directions in Therapeutics for Neurological Complications of HIV Infections.

The pace of therapeutic developments in HIV presents unique challenges to the neurologist caring for patients. Combination antiretroviral therapy (cART) is remarkably effective in suppressing viral replication, preventing, and often even reversing disease progression. Still, not every patient benefits from cART for a variety of reasons, ranging from the cost of therapy and the burden of lifelong daily treatment to side effects and inadequate access to medical care. Treatment failure inevitably leads to disease progression and opportunistic complications. Many of these complications, even those that are treatable, produce permanent neurological disability. With ART, immune recovery itself may paradoxically lead to severe neurological disease; strategies for managing so-called immune reconstitution inflammatory syndrome are beginning to show benefits. Effective cART may nevertheless leave in its wake persistent neurocognitive impairment. Treatments for persistent impairment despite virologic suppression and good immune recovery are being tested but are not yet proven. As we shall see, these treatments target several proposed mechanisms including cerebral small vessel disease, which is highly prevalent in HIV. Most recently, an ambitious initiative has been undertaken to develop interventions to eradicate HIV. This will require elimination of all infectious forms of viral nucleic acid throughout the body. The influence of these interventions on the brain remains to be characterized. Meanwhile, clinical investigators continue to develop antiretroviral treatments that optimize effectiveness, convenience, and tolerability, while minimizing long-term toxicities.

Dual infective pathology in patients with cryptococcal meningitis.

Coinfection of the nervous system by two distinct nonviral organisms is uncommon and often undiagnosed. Medical teaching emphasizes that a single pathologic process should be sought; however, in the presence of severe immunocompromise this approach may not hold true. We describe seven HIV-1 seropositive patients with cryptococcal meningitis, three of whom had a proven nervous system infection with a second organism: concurrent tuberculous meningitis, a tuberculoma, and the first documented case of cryptococcal meningitis and neurosyphilis.

Cryptococcus neoformans meningoencephalitis in African children with acquired immunodeficiency syndrome.

BACKGROUND: The number of children with AIDS in Africa is high. Such children may be at risk for cryptococcal meningoencephalitis, but data are scarce regarding this disease in our population. METHODS: We examined records of HIV-infected children (< or =16 years) diagnosed with cryptococcal meningoencephalitis in Harare, Zimbabwe, between 1995 and 2000. To elucidate features unique to pediatric disease, the children were compared with adult patients with HIV-associated cryptococcal meningoencephalitis. RESULTS: Thirteen children presented to our institution with headache (85%), nuchal rigidity (69%), vomiting (46%), impaired mental status (38%), convulsions (38%) and focal neurologic signs (23%). The mean duration of symptoms before diagnosis was 9 days. Cerebrospinal fluid examination revealed normal white blood cell counts in 64%, protein value in 67% and glucose concentration in 57% of patients. Children were more likely than adults to have seizures (38% vs. 11%, P = 0.02) and normal cerebrospinal fluid protein (67% vs. 10%, P < 0.01). The in-hospital mortality was 43%. Convulsions (P = 0.05) and impaired mental status (P < 0.01) were associated with increased mortality CONCLUSIONS: Cryptococcal meningoencephalitis in African children presents acutely or subacutely, can have a fulminant picture and is consistent with progressive meningoencephalitis.

Latex agglutination test negative cryptococcal meningitis in an immuno-competent individual: a case report.

We report a case with progressive mental deterioration and persistent low grade fever, who was diagnosed to have cryptococcal meningitis. This case is unique in that the cryptococcal latex agglutination antigen test was consecutively negative. The diagnosis was made by sequential CSF culture.

[Cryptococosis and HIV/AIDS: a review of 21 cases reported in the Tropical Diseases Centre, Ho Chi Minh City (Vietnam)]. / Méningite à Cryptococcus neoformans chez les patients infectés par le VIH/sida dans le contexte du Centre des maladies tropicales, Ho Chi Minh-ville (Vietnam).

Cryptococcus neoformans affections during HIV-infection are frequent and serious. The aim of this study was to analyse the epidemiological, clinical, biological and therapeutic characteristics of cryptococcal meningitis in HIV-positive patients, admitted into the Center for Tropical Diseases Ho Chi Minh City (Vietnam), during a 5-month period (May-September 2001). Twenty-one patients (20 men and one woman) were included (identification of C. neoformans from the cerebrospinal fluid). The mean age was 28 years. The majority of patients had been living in Ho Chi Minh City (48%). The use of drugs and unprotected sexual relations were the principal risk factors of HIV-infection. The paucity and the confusion of clinical signs and symptoms, along with a high frequency of meningitis have been analysed. Clinical presentation features included: headache (95%), emaciation (90%), oro-pharyngeal candidiasis (90%), stiff neck (80%), nausea/vomiting (70%), fever (67%), coughing (38%), diarrhoea (33%), skin lesions (5%), convulsion (5%), photophobia (5%), and hemiparesis (5%). The severity of the prognosis was mainly linked to the delay before hospitalization, to the possible association with other opportunistic infections, and to the availability of appropriate treatment.