Diagnosis Of Cryptococcosis Research Articles

Nodules multiples du visage révélant une cryptococcose disséminée chez un patient immunocompétent

Cryptococcosis is a potentially severe infection that usually occurs in a setting of immunosuppression. Its occurrence outside of this context is rare. We report a case of disseminated cryptococcosis revealed by a spectacular skin disease in an immunocompetent patient. A 40-year-old male patient had been presenting multiple nodules and tumors on his face for one month in a context of asthenia and intermittent fever. Histological examination of a skin biopsy revealed encapsulated yeasts strongly suggestive of Cryptococcus neoformans. Mycological examination of the skin biopsy and cerebrospinal fluid isolated Cryptococcus gattii. The blood cultures were positive. Brain MRI demonstrated cryptococcal parenchymal involvement. Screening for primary or secondary immunodeficiency was negative. The patient received amphotericin B 1mg/kg/day and fluconazole 600mg/day but died 2months after diagnosis. Cryptococcosis is a potentially severe infection caused by C.neoformans. This rare condition occurs most commonly in patients with profound deficiency in terms of cellular immunity. Although rare, the occurrence of cryptococcosis in immunocompetent patients is possible, and in this event the signs are highly polymorphic, which usually makes it very difficult to diagnose. The diagnosis of cryptococcosis is based on the identification by direct examination and after staining with India ink of encapsulated yeasts of the Cryptococcus genus. Culture on Sabouraud medium is essential for identification of the species. Treatment for disseminated cryptococcosis involves amphotericin B, often associated with flucytosine IV. In the event of meningitis infection in non-HIV patients, mortality continues to be around 15%, despite adequate medical treatment. Although rare, cryptococcosis can occur in immunocompetent subjects. The prognosis is severe even after treatment.

Performance of the Cryptococcal Antigen Lateral Flow Assay in Non-HIV-Related Cryptococcosis.

The cryptococcal antigen lateral flow assay (CrAg LFA) was evaluated for the diagnosis of cryptococcosis in HIV-negative patients. The sensitivity was excellent, suggesting that this assay can replace conventional testing based on latex agglutination (LA). CrAg LFA and LA titers were correlated but were not directly comparable, with implications for conversion between assays.

Validation and clinical application of a molecular method for the identification of Cryptococcus neoformans/Cryptococcus gattii complex DNA in human clinical specimens

The diagnosis of cryptococcosis is usually performed based on cultures of tissue or body fluids and isolation of the fungus, but this method may require several days. Direct microscopic examination, although rapid, is relatively insensitive. Biochemical and immunodiagnostic rapid tests are also used. However, all of these methods have limitations that may hinder final diagnosis. The increasing incidence of fungal infections has focused attention on tools for rapid and accurate diagnosis using molecular biological techniques. Currently, PCR-based methods, particularly nested, multiplex and real-time PCR, provide both high sensitivity and specificity.In the present study, we evaluated a nested PCR targeting the gene encoding the ITS-1 and ITS-2 regions of rDNA in samples from a cohort of patients diagnosed with cryptococcosis. The results showed that in our hands, this Cryptococcus nested PCR assay has 100% specificity and 100% sensitivity and was able to detect until 2 femtograms of Cryptococcus DNA.

Evaluation of a new cryptococcal antigen lateral flow immunoassay in serum, cerebrospinal fluid and urine for the diagnosis of cryptococcosis: a meta-analysis and systematic review.

BackgroundA new lateral flow immunoassay (LFA) for the detection of cryptococcal antigen was developed.ObjectiveWe aimed to systematically review all relevant studies to evaluate the diagnostic accuracy of the cryptococcal antigen LFA on serum, CSF and urine specimens.MethodsWe searched public databases including PubMed, Web of Science, Elsevier Science Direct and Cochrane Library for the English-language literature published up to September 2014. We conducted meta-analyses of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratios (DOR) and SROC of LFA in serum and CSF, respectively. The sensitivity of LFA in urine was also analyzed. Subgroup analyses were carried out to analyze the potential heterogeneity.Results12 studies were included in this study. The pooled sensitivity and specificity values of LFA in serum were 97.6% (95% CI, 95.6% to 98.9%) and 98.1% (95% CI, 97.4% to 98.6%), respectively. The average PLR of LFA in serum was 43.787 (95% CI, 22.60–84.81) and the NLR was 0.03 (95% CI, 0.01–0.09). The pooled DOR was 2180.30 (95% CI, 868.92–5471.00) and the AUC was 0.9968. The pooled sensitivity and specificity values of LFA in CSF were 98.9% (95% CI, 97.9% to 99.5%) and 98.9% (95% CI, 98.0% to 99.5%), respectively. The average PLR of LFA in serum was 48.83 (95% CI, 21.59–110.40) and the NLR was 0.02 (95% CI, 0.01–0.04). The pooled DOR was 2931.10 (95% CI, 1149.20–7475.90) and the AUC was 0.9974. The pooled sensitivity value of LFA in urine was 85.0% (95% CI, 78.7% to 90.1%)ConclusionsThe study demonstrates a very high accuracy of LFA in serum and CSF for the diagnosis of cryptococcosis in patients at risk. LFA in urine can be a promising sample screening tool for early diagnosis of cryptococcosis.

Large-scale clinical validation of a lateral flow immunoassay for detection of cryptococcal antigen in serum and cerebrospinal fluid specimens

We compared a lateral flow immunoassay (LFA) to a currently used enzyme immunoassay for detection of cryptococcal antigen in 396 sera and 651 cerebrospinal fluid specimens. We found 97% concordance between the 2 assays. The LFA detected an additional 22 positives. Overall, the LFA had sensitivity of 100% and specificity of 99.6% for the diagnosis of cryptococcosis. The LFA is rapid, accurate, and easy to perform, and it is suitable for routine patient care testing.

Rapid diagnosis of cryptococcosis using an antigen detection immunochromatographic test

Current methods for cryptococcal antigen detection have some limitations. This study aimed at evaluating a lateral flow assay (LFA) for the diagnosis of cryptococcosis in a French University medical center. A retrospective study was performed on samples collected from patients with a definitive diagnosis of cryptococcosis (group I 66 samples; 28 patients) or with non-Cryptococcus invasive fungal infection (group II 18 samples; 17 patients). In addition, 274 samples from 205 consecutive patients, either suspected of cryptococcal infection or routinely screened during their follow-up, were prospectively tested (group III). Cryptococcal antigen was assayed using LFA and an EIA. A latex-based test was used for confirmation. Sensitivity calculated on group I and specificity on group II, were respectively at 100% and 90.0%. Two false positives were related to Trichosporon fungemia. Per-sample analysis on group III revealed sensitivity, specificity, positive and negative predictive values all at 100% for CSF, and at 100%, 98.9%, 75% and 100%, respectively for serum samples. LFA enabled the diagnosis of two cases of asymptomatic cryptococcosis. The excellent diagnostic value and practicality (visual reading results in 15min) of LFA make it fully appropriate for the diagnosis of cryptococcosis in this particular setting.

Cryptococcosis diagnosis and treatment: What do we know now

Cryptococcosis has evolved into a major invasive fungal disease over the last century. Its primary epidemiology has been focused on three major outbreaks of disease that reflects both changing environmental exposures and growth of host risk factors. The molecular understandings of yeast pathobiology have been bolstered by identification of the yeast’s dynamic genomic structures and functions. It is during these new insights into epidemiology and pathobiology that we have also improved our diagnosis of this infection with a new point-of-care, simple, cheap test which utilizes a lateral flow assay for antigen detection. With methods for effective identification of Cryptococcus in the host, the principles for management of this deadly infection include both use of old drugs and new insights into treatment strategies to improve outcome. In this review there are a series of recent insights, opinions, and facts which attempt to summarize our present knowledge base for this deadly fungal central nervous system infection with a particular emphasis on its diagnosis and management.

Methods of rapid diagnosis for the etiology of meningitis in adults.

Infectious meningitis may be due to bacterial, mycobacterial, fungal or viral agents. Diagnosis of meningitis must take into account numerous items of patient history and symptomatology along with regional epidemiology and basic cerebrospinal fluid testing (protein, etc.) to allow the clinician to stratify the likelihood of etiology possibilities and rationally select additional diagnostic tests. Culture is the mainstay for diagnosis in many cases, but technology is evolving to provide more rapid, reliable diagnosis. The cryptococcal antigen lateral flow assay (Immuno-Mycologics) has revolutionized diagnosis of cryptococcosis and automated nucleic acid amplification assays hold promise for improving diagnosis of bacterial and mycobacterial meningitis. This review will focus on a holistic approach to diagnosis of meningitis as well as recent technological advances.

Cryptococcosis: An Enigmatic Mycosis of Humans and Animals

Zoonoses with multiple etiologies affecting immunocompromised hosts have become a matter of concern presently, among the physicians and veterinarians. Among the zoonoses, cryptococcosis is considered a common and important mycozoonosis of global significance mainly affecting HIV/ AIDS patients. Cryptococcosis is primarily caused by Cryptococcus neoformans and Cryptococcus gattii, which are found in the soil contaminated with avian droppings or eucalyptus trees and decaying woods. Cryptococcus neoformans can survive in the saprobic environment for about 20 years. The respiratory tract is recognized as the principal mode of entry of the pathogen, and the source of infection is exogenous. It is believed that humans and animals acquire cryptococcal infection from saprobic reservoirs. Cryptococcosis occurs in sporadic and epidemic form resulting in high morbidity and mortality in the susceptible hosts. The disease is most often found in cats but has also been reported in cattle, dogs, horses, sheep, goat and other animals. Cryptococcosis is the first manifestation of HIV infection in 26 to 45% of patients, and recent data indicate that C. neoformans appears to potentiate HIV infection. Cryptococcal meningitis alone kills approximately 624,000 people in the world annually. The direct demonstration of the pathogen in the clinical specimens and its isolation in pure and luxuriant form remains the “gold standard” to the diagnosis of cryptococcosis. The routine application of Pal’s sunflower seed medium and Narayan stain in public health and microbiology laboratories will certainly help in the study of this enigmatic mycosis in humans as well as in animals.

Cryptococcal meningitis with secondary cutaneous involvement in an immunocompetent host

Cryptococcosis is a potentially fatal fungal disease caused by variants of Cryptococcus neoformans species. The respiratory tract is the usual portal of entry, with a peculiar predilection to invade the central nervous system. The skin can be secondarily involved in disseminated infection or be exceptionally involved as primary cutaneous infection by inoculation. The disease is mostly seen in immunodeficiency states. The diagnosis is frequently unsuspected in immunocompetent patients. We report a case of disseminated cryptococcal meningitis in an immunocompetent young adult. The cutaneous eruption prompted the accurate diagnosis. The patient, a 20-year-old female, had fever, cough, headache and intractable vomiting for the past two months and was being managed as a case of tuberculous meningitis. Two weeks after starting antituberculous treatment she developed umbilicated papules on the head and neck region. Necessary laboratory workup identified C. neoformans in cerebrospinal fluid (CSF) and skin specimens. The titers of cryptococcal antigen were measured in CSF and serum for diagnostic and prognostic purposes. Anti-fungal treatment resulted in regression of the cutaneous lesions and resolution of systemic complaints. The case highlights the need for high degree of suspicion, especially in healthy young adults, in the diagnosis of cryptococcosis. The cutaneous eruptions can be the first manifestation or a diagnostic clue of enormous significance.

Correlation Of Cryptococcal Antigen Assay With C-reactive Protein As Serum And Urine Biomarker In Cryptococcal Meningitis: Experience In A Tertiary Hospital

Correlation Of Cryptococcal Antigen Assay With C-reactive Protein As Serum And Urine Biomarker In Cryptococcal Meningitis: Experience In A Tertiary Hospital

Cryptococcosis in cats: ABCD guidelines on prevention and management.

Cryptococcosis is worldwide the most common systemic fungal disease in cats; it is caused by the Cryptococcus neoformans- Cryptococcus gattii species complex, which includes eight genotypes and some subtypes (strains) with varying geographical distribution, pathogenicity and antimicrobial susceptibility. Cats acquire the infection from a contaminated environment. The prognosis is favourable in most cases, provided a diagnosis is obtained sufficiently early and prolonged treatment is maintained. Basidiospores are the infectious propagules of Cryptococcus species as they penetrate the respiratory system and induce primary infection. Asymptomatic colonisation of the respiratory tract is more common than clinical disease. Avian guanos, particularly pigeon droppings, offer favourable conditions for the reproduction of C neoformans. Both Cryptococcus species are associated with decaying vegetation. Cryptococcosis caused by C neoformans or C gattii is indistinguishable clinically. The disease can present in nasal, central nervous system (which can derive from the nasal form or occur independently), cutaneous and systemic forms. An easy and reliable test for cryptococcosis diagnosis is antigen detection in body fluids. Only isolation and polymerase chain reaction allow identification of the species genotype. Amphotericin B, ketoconazole, fluconazole and itraconazole have all been used to treat cats. Surgical excision of any nodules in the skin, nasal or oral mucosa assists recovery. Continued treatment is recommended until the antigen test is negative. Efficient preventive measures have not been demonstrated. Vaccines are not available.

Evaluation of a rapid lateral flow immunoassay for the detection of cryptococcal antigen for the early diagnosis of cryptococcosis in HIV patients in Colombia

A previous study carried out in a tertiary care hospital in Colombia demonstrated the usefulness of the Cryptococcus capsular antigen detection by latex (CrAg Latex) in the early diagnosis of cryptococcosis in HIV-infected patients with low CD4 + levels. The aim of this study was to establish the performance of a new rapid lateral flow assay (CrAg LFA) in preserved sera of those HIV-infected patients collected between 2001 and 2006. A total of 421 sera from 297 patients with a confirmed diagnosis of HIV were tested with CrAg LFA and results compared with those obtained with CrAg Latex. All patients provided informed consent for specimen collection. A concordance of 100% was found between positive results obtained by both methods. However, 13 sera that were negative by CrAg Latex, were positive by CrAg LFA (3.1%). In these positive patients, median of CD4 + levels was 67 cells/μl (8-608 cells/μl), while median of viral load was 118,965 copies/ml (50-500,000 copies/ml). Patients who were negative for cryptococcosis had a median of 177 cells/μl in CD4 + levels (4-2516 cells/μl) and a median of 62,318 copies/ml in viral loads (25-50,000 copies/ml). A significant statistical difference was found when comparing CD4 + levels and viral load in patients positive for cryptococcosis and those that were proven to be negative (P < 0.0001). The use of Point-of-Care Tests (POCT) like CrAg LFA play an important role in the diagnosis of infectious diseases, especially in resource limited settings, where it will be a useful means to diagnose cryptococcosis early in HIV patients.

Cryptococcose neuroméningée chez un patient porteur d’une valve de dérivation ventriculo-péritonéale suivi pour sarcoïdose pulmonaire

The fungus Cryptococcus neoformans can cause common opportunistic infection in acquired immune deficiency syndrome (AIDS) patients. But other conditions can be associated with sarcoidosis. Meningoencephalitis is the most common manifestation of this disease. One of the most important neurological complications is the development of intracranial hypertension (ICH), which may result in high morbidity and mortality. We report the case of a patient harboring a ventriculoperitoneal shunt, and having contracted a cryptococcal meningitis as a risk factor for pulmonary sarcoidosis. Brain MRI showed arachnoiditis, with a mass in contact with the right frontal horn. Indian ink staining of the cerebrospinal fluid (CSF) showed positivity that was confirmed by the identification of Cryptococcus neoformans after culture. The evolution was favorable under medical treatment with removal of material. The relationship between sarcoidosis and cryptococcosis, described in the literature is not coincidental but is a rare complication of sarcoidosis of potential severity (40 % of mortality). Sarcoidosis is a common systemic disease that may increase host susceptibility to CNS cryptococcal infection without any other signs or symptoms of host immunosuppression. The diagnosis of cryptococcosis should be evoked as a differential diagnosis of neuro-sarcoidosis.

The cryptococcal antigen lateral flow assay for diagnosis of cryptococcosis

Cryptococcosis is a life-threatening fungal infection causing meningitis worldwide, principally in immune-compromised individuals. This disease is caused by two main species, <i>Cryptococcus neoformans</i> and <i>Cryptococcus gattii</i>. Diagnosis has traditionally relied upon laboratory tests such as serology (latex agglutination or enzyme immunoassay) or culture. In 2011, the US Food and Drug Administration (FDA) approved a dipstick-test lateral flow assay (Immuno-Mycologics, USA) for semi-quantitative detection of cryptococcal antigen. Potential advantages of this assay over traditional methods include stability of reagents at room temperature, ease of use and rapid turn-around time. The World Health Organization has recommended that this assay may be used to screen patients with HIV infection for cryptococcal antigen. This presentation will discuss utility of the cryptococcal antigen lateral flow assay in the diagnostic laboratory and review current evidence, areas which remain to be explored and potential future developments in the diagnosis of cryptococcosis.

Diagnosis of Cryptococcosis and Prevention of Cryptococcal Meningitis Using a Novel Point-of-Care Lateral Flow Assay.

Despite access to antiretroviral therapy, mortality from cryptococcal meningitis (CM) is high among persons with advanced HIV infection in sub-Saharan Africa. Cryptococcal antigen (CrAg) is present several weeks to months before the onset of symptoms of meningitis and can be screened to prevent life threatening meningitis. Recently, the World Health Organisation recommended that a new rapid CrAg lateral flow ‘‘dipstick” assay (LFA) is to be used to screen HIV-infected persons with CD4 counts of less than 100 cells/µL. In this paper, we describe two cases of cryptococcosis with differing outcomes. In the first case, the new CrAg LFA was used as part of a screen and preemptive treatment strategy to prevent CM. In the second case, our patient had no access to the CrAg LFA and subsequently developed life threatening meningitis. To the best of our knowledge, this is the first case report of cryptococcosis diagnosed using this novel assay.

Pulmonary cryptococcosis in an immunocompetent patient—A case report

Cryptococcosis is an infection caused by fungi that belong to the genus Cryptococcus. There are several species of Cryptococcus, but two species—Cryptococcus neoformans and Cryptococcus gattii—cause nearly all cryptococcal infections in humans. Cryptococcosis is one of the most common fungal infections in Brazil and becomes even more important after the onset of the AIDS epidemic. The lung is the main gateway, and also is the most common site, with diverse clinical manifestations ranging from an asymptomatic to severe pneumonia. When symptommatic, most patients present with fever and cough with expectoration or hemoptysis. The most common radiological findings in immunocompetent patients are located images of masses and nodules, while immunosuppression shows interstitial infiltrates and diffuses interstitial opacity. This is a case report of a patient in the third decade of life with breathing-dependent pain at the base of the left hemithorax, who has radiological examination of a mass in the left lung base in contact with the pleura mimicking malignant lung. Lobectomy was performed, as well as the pathological diagnosis of cryptococcosis.

A comparison of cases of paediatric-onset and adult-onset cryptococcosis detected through population-based surveillance, 2005–2007

We compared the epidemiology of laboratory-confirmed paediatric cryptococcal disease with adult-onset disease in the South African population. The study was an active, prospective, population-based, laboratory-based surveillance in South Africa. We compared cases of paediatric cryptococcosis (<15 years) with cases of adult-onset cryptococcosis that were reported to the surveillance programme between 1 January 2005 and 31 December 2007. The case definition was based on a positive India ink test, cryptococcal antigen test or cryptococcal culture. Clinical case data were obtained at enhanced surveillance sites. Of 16,192 incident episodes of cryptococcosis in South Africa, 361 (2%) episodes occurred among children. In 2007, incidence was one and 19 cases per 100,000 persons in the general paediatric and adult populations and was 47 and 120 cases per 100,000 persons for HIV-infected children and adults, respectively. Among children, a bimodal peak in incidence was evident in the less than 1-year age group and in the 5 age group. Most children (64%) and adults (63%) were severely immunocompromised (CD4 T-lymphocyte cell count < 50 cells/μl) at the time of diagnosis. On multivariable analysis, children were significantly more likely than adults to be male, diagnosed on blood culture, infected with Cryptococcus gattii, treated with amphotericin B and admitted for a longer stay in hospital. This series of 361 cases of paediatric cryptococcosis is by far the largest described to date. The diagnosis of cryptococcosis should be considered in the paediatric HIV-infected population, especially among those who are severely immunocompromised.

CrAg lateral flow assay for cryptococcosis

Importance of field: Cryptococcal meningitis is a leading cause of death globally among people with AIDS. In sub-Saharan Africa, cryptococcosis is estimated to kill more people than tuberculosis. Cryptococcosis is also an important infectious disease among immunosuppressed patients in countries with advanced medical care. Early diagnosis is the key to effective treatment, particularly in patients in resource-limited settings. A new lateral flow immunoassay (LFA) for cryptococcal antigen (CrAg) allows for rapid and inexpensive diagnosis of cryptococcosis at or near the point of patient contact. This article reviews the need for improved diagnostics for cryptococcal meningitis and describes the features of an ideal diagnostic. The design of a new LFA for CrAg is described as well as the results of initial clinical evaluation of the CrAg LFA. The CrAg LFA is recommended for use with serum, plasma or CSF for diagnosis of cryptococcal meningitis or non-meningeal cryptococcal disease in symptomatic patients. There is a need for further evaluation of LFA for screening of asymptomatic patients. However, the LFA is emerging as a valuable tool for screening of serum or plasma in ART-naive adults with CD4 counts less than 100 cells/mm(3) in geographic regions with a high prevalence of cryptococcal antigenemia. CrAg screening has the potential to identify patients with asymptomatic cryptococcal infection who should receive preemptive antifungal therapy.

Evaluation of the detection of melanin by the Fontana-Masson silver stain in tissue with a wide range of organisms including Cryptococcus

It is not uncommon for surgical pathologists to encounter yeast and yeast-like organisms in tissue sections, and correct identification is imperative for guiding therapy. The Fontana-Masson silver stain for detecting melanin has been accepted as a relatively specific stain for diagnosing cryptococcosis in tissue based on few studies with limited numbers of organisms. This study was designed to test the value of the Fontana-Masson silver by investigating a large collection of tissues with infections that may mimic cryptococcosis. Cases of cryptococcosis and other infections that can morphologically mimic it were identified in the pathology archives of The Johns Hopkins Hospital and The Armed Forces Institute of Pathology. Overall, Fontana-Masson silver was positive in 25 (56%) of 45 cases, including infections caused by Cryptococcus neoformans (9/9), Coccidioides immitis (7/7), Blastomyces dermatitidis (4/10), Paracoccidioides brasiliensis (2/2), Lacazia loboi (1/1), and Rhinosporidium seeberi (1/1). The percentage of organisms staining varied widely, from less than 1% to 100%. Fontana-Masson silver was negative in all infections caused by Histoplasma capsulatum (n = 10), Histoplasma duboisii (n = 1), Sporothrix schenckii (n = 1), and the alga genus Prototheca (n = 2). Fontana-Masson silver was 100% sensitive for cryptococcosis. The specificity was low, however, with 5 of 9 noncryptococcal species being positive in some cases. These results need to be confirmed and extended to other isolates and species but it is clear that many organisms in the morphological differential diagnosis of cryptococcosis can be Fontana-Masson silver stain positive. Accordingly, results of the Fontana-Masson silver stain, especially a positive, should be interpreted cautiously and only in the context of the organism's morphological features and host factors.