Serious fungal infections in Thailand

The burden of serious fungal infection in Thailand is increasing but data regarding its incidence and prevalence are lacking. In this study we aimed to estimate the burden of serious fungal diseases in Thailand based on the size of the populations at risk and available epidemiological databases. Data derived from The Bureau of Epidemiology, Department of Disease Control, Thai Ministry of Public Health, World Health Organisation, international and local reports, and some unreported data were used. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology by LIFE. Recurrent vulvovaginal candidiasis (>4 episodes per year) is estimated to occur in 3,310 per 100,000 population. Using a previously described rate that 14/10,000 admissions are with fungaemia and 94% of those are Candida, we estimated 8,650 patients with candidaemia. The prevalence of chronic pulmonary aspergillosis is relatively high with a total of 19,044, approximately half subsequent to pulmonary tuberculosis. Invasive aspergillosis is estimated to affect 941 patients following leukaemia therapy, transplantations, and chronic obstructive pulmonary disease, approximately 1.4/100,000. In addition, allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation were estimated at approximately 58.4/100,000 and 77/100,000, respectively. Given approximately 8,134 new cases of AIDS annually, cryptococcal meningitis, Pneumocystis pneumonia, and Talaromyces marneffei infection are estimated at 1.9/100,000, 2.6/100,000, and 0.3/100,000, respectively. The present study indicates that about 1.93% (1,254,562) of the population is affected by serious fungal infections. Owing to the lack of data, reports, and statistics, the number of patients with mycoses in Thailand can only be estimated

A case of feline gastrointestinal eosinophilic sclerosing fibroplasia associated with phycomycetes

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) is a recently described inflammatory condition of domestic cats with unknown aetiology. A proportion of cases of FGESF are associated with bacteria, but antibiotic treatment is ineffective. It has been hypothesized that genetically predisposed cats may develop FGESF in response to the introduction of bacteria or other antigens into the intestinal wall. A 9- month-old male Persian cat presented with a history of marked acute haematemesis. A mass (10 cm diameter) was detected within the pylorus and proximal duodenum and this was not surgically accessible. On necropsy examination the duodenal wall was seen to be markedly thickened with extensive mucosal ulceration. Microscopically, there were haphazardly oriented trabecular bands of dense eosinophilic collagen,separated by wide, clear areas containing variable numbers of fibroblasts, eosinophils, mast cells, neutrophils,macrophages, lymphocytes and plasma cells. Numerous pleomorphic, non-parallel walled, sparsely septate hyphae, characteristic of phycomycetes, were present within the collagen matrix. Colonies of gram-positive and gram-negative rods were also present within the lesion. This is the first description of FGESF with intralesional fungi

Epidemiology of Cryptococcus gattii, British Columbia, Canada, 1999–2007

Incidence is high, but the predominant strain does not seem to cause greater illness or death than do other strains

Survey of laboratory practices for diagnosis of fungal infection in seven Asian countries: An Asia Fungal Working Group (AFWG) initiative

An online survey of mycology laboratories in seven Asian countries was conducted to assess the status, competence, and services available. Country representatives from the Asia Fungal Working Group (AFWG) contacted as many laboratories performing mycology diagnosis as possible in their respective countries, requesting that the laboratory heads complete the online survey. In total, 241 laboratories responded, including 71 in China, 104 in India, 11 in Indonesia, 26 in the Philippines, four in Singapore, 18 in Taiwan, and seven in Thailand. Overall, 129/241 (53.5%) surveyed mycology laboratories operate as separate designated mycology laboratories, 75/241 (31.1%) conduct regular formal staff training, 103/241 (42.7%) are accredited, and 88/157 (56.1%) participate in external quality assurance scheme (EQAS) programs. Microscopy and culture methods are available in nearly all laboratories, although few perform DNA sequencing (37/219; 16.9%) or use matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) (27/219; 12.3%) for isolate identification. Antifungal susceptibility testing is performed in 142/241 (58.9%) laboratories, mainly for yeasts. The most commonly performed nonculture diagnostic is cryptococcal antigen testing (66 laboratories), followed by galactomannan testing (55), polymerase chain reaction (PCR) diagnosis (37), and beta-D-glucan testing (24). Therapeutic drug monitoring is conducted in 21 laboratories. There is almost no access to advanced diagnostic tests, like galactomannan, β-D-glucan, and PCR, in the surveyed laboratories in Indonesia, the Philippines, and Thailand. These results highlight the need for development of quality laboratories, accreditation and training of manpower in existing laboratories, and access to advanced non–culture-based diagnostic tests to facilitate the diagnosis of fungal infections in Asia

Clinicians’ challenges in managing patients with invasive fungal diseases in seven Asian countries: An Asia Fungal Working Group(AFWG) Survey

Background: Invasive fungal diseases (IFD) are a serious threat, but physicians in Asia lack access to many advanced diagnostics in mycology. It is likely that they face other impediments in the management of IFD. A gap analysis was performed to understand the challenges Asian physicians faced in medical mycology. Methods: The Asia Fungal Working Group (AFWG) conducted a web-based survey on management practices for IFD among clinicians in China, India, Indonesia, Philippines, Singapore, Taiwan and Thailand. Findings: Among 292 respondents, 51.7% were infectious disease (ID) specialists. Only 37% of respondents had received formal training in medical mycology. They handled only around 2–4 proven cases of each fungal infection monthly, with invasive candidiasis the most common. For laboratory support, the majority had access to direct microscopy (96%) and histopathology (87%), but galactomannan and azole levels were available to 60% and 25% of respondents, respectively. The majority (84%) used clinical parameters for treatment response monitoring, and 77% followed the Infectious Diseases Society of America guidelines. The majority (84%) did not use the services of an ID physician. Where febrile neutropenia was concerned, 74% of respondents used the empirical approach. Only 30% had an antifungal stewardship program in their hospital. Eighty percent could not use preferred antifungals because of cost. Interpretation: The survey identified inadequacies in medical mycology training, non-culture diagnostics, access to antifungal drugs, and local guidelines as the major gaps in the management of IFDs in Asian countries. These gaps are targets for improvement

Genomic epidemiology of Cryptococcus yeasts identifies adaptation to environmental niches underpinning infection across an African HIV/AIDS cohort.

Emerging infections caused by fungi have become a widely recognized global phenomenon and are causing an increasing burden of disease. Genomic techniques are providing new insights into the structure of fungal populations, revealing hitherto undescribed fine-scale adaptations to environments and hosts that govern their emergence as infections. Cryptococcal meningitis is a neglected tropical disease that is responsible for a large proportion of AIDS-related deaths across Africa; however, the ecological determinants that underlie a patient's risk of infection remain largely unexplored. Here, we use genome sequencing and ecological genomics to decipher the evolutionary ecology of the aetiological agents of cryptococcal meningitis, Cryptococcus neoformans and Cryptococcus gattii, across the central African country of Zambia. We show that the occurrence of these two pathogens is differentially associated with biotic (macroecological) and abiotic (physical) factors across two key African ecoregions, Central Miombo woodlands and Zambezi Mopane woodlands. We show that speciation of Cryptococcus has resulted in adaptation to occupy different ecological niches, with C. neoformans found to occupy Zambezi Mopane woodlands and C. gattii primarily recovered from Central Miombo woodlands. Genome sequencing shows that C. neoformans causes 95% of human infections in this region, of which over three-quarters belonged to the globalized lineage VNI. We show that VNI infections are largely associated with urbanized populations in Zambia. Conversely, the majority of C. neoformans isolates recovered in the environment belong to the genetically diverse African-endemic lineage VNB, and we show hitherto unmapped levels of genomic diversity within this lineage. Our results reveal the complex evolutionary ecology that underpins the reservoirs of infection for this, and likely other, deadly pathogenic fungi

Cryptococcus neoformans Requires a Functional Glycolytic Pathway for Disease but Not Persistence in the Host

Cryptococcus neoformans is an important fungal pathogen of immunocompromised individuals, with a close relative, Cryptococcus gattii, emerging as a serious threat for the immunocompetent. During initial infection, C. neoformans colonizes the airspaces of the lungs, resulting in pneumonia, and subsequently migrates to the central nervous system (CNS). We sought to understand fungal carbon utilization during colonization of these fundamentally different niches within the host, in particular the roles of gluconeogenesis and glycolysis. We created mutants at key points in the gluconeogenesis/glycolysis metabolic pathways that are restricted for growth on lactate and glucose, respectively. A phosphoenolpyruvate carboxykinase mutant (the pck1∆ mutant), blocked for entry of 2- and 3-carbon substrates into gluconeogenesis and attenuated for virulence in a murine inhalation model, showed wild-type (WT) persistence in a rabbit cerebrospinal fluid (CSF) model of cryptococcosis. Conversely, both the pyruvate kinase (pyk1∆) and the hexose kinase I and II (hxk1∆/hxk2∆) mutants, which show impaired glucose utilization, exhibited severely attenuated virulence in the murine inhalation model of cryptococcosis and decreased persistence in the CNS in both the rabbit CSF and the murine inhalation models while displaying adequate persistence in the lungs of mice. These data suggest that glucose utilization is critical for virulence of C. neoformans and persistence of the yeast in the CNS

Surface Localization of Glucosylceramide during Cryptococcus neoformans Infection Allows Targeting as a Potential Antifungal

Cryptococcus neoformans (Cn) is a significant human pathogen that, despite current treatments, continues to have a high morbidity rate especially in sub-Saharan Africa. The need for more tolerable and specific therapies has been clearly shown. In the search for novel drug targets, the gene for glucosylceramide synthase (GCS1) was deleted in Cn, resulting in a strain (Δgcs1) that does not produce glucosylceramide (GlcCer) and is avirulent in mouse models of infection. To understand the biology behind the connection between virulence and GlcCer, the production and localization of GlcCer must be characterized in conditions that are prohibitive to the growth of Δgcs1 (neutral pH and high CO2). These prohibitive conditions are physiologically similar to those found in the extracellular spaces of the lung during infection. Here, using immunofluorescence, we have shown that GlcCer localization to the cell surface is significantly increased during growth in these conditions and during infection. We further seek to exploit this localization by treatment with Cerezyme (Cz), a recombinant enzyme that metabolizes GlcCer, as a potential treatment for Cn. Cz treatment was found to reduce the amount of GlcCer in vitro, in cultures, and in Cn cells inhabiting the mouse lung. Treatment with Cz induced a membrane integrity defect in wild type Cn cells similar to Δgcs1. Cz treatment also reduced the in vitro growth of Cn in a dose and condition dependent manner. Finally, Cz treatment was shown to have a protective effect on survival in mice infected with Cn. Taken together, these studies have established the legitimacy of targeting the GlcCer and other related sphingolipid systems in the development of novel therapeutics