Editorial
Volume 2 Issue 3 - 2018
Cryptococcal Meningitis: A Lethal Fungal Infection
Neelabh* and Karuna Singh
Department of Zoology, Banaras Hindu University, Varanasi-221005
*Corresponding Author: Neelabh, Department of Zoology, Banaras Hindu University, Varanasi-221005.
Received: May 22, 2018; Published: May 31, 2018
Introduction
Cryptococcosis is an important fungal disease having a global impact and being caused by the species Cryptococcous. Cryptococcusspp. are attributed to be the only prominent human fungal pathogens from the large group of basidiomycete fungi that are a growing threat not only to human health, but also to animal and plant health. These fungi have many properties to their advantage such as high virulence, generalism, long-lived environmental stages, and the potential for wide dispersal and rapid evolutionary change (Fisher., et al. 2012).
There are twospecies associated with Cryptococcus that can cause disease 1) Cryptococcus neoformans 2) Cryptococcus gattii(Byrnes III., et al. 2011). In general C. neoformans is associated with causing disease in the immune compromised patients whereas C. gattiican cause infections in healthy individuals as well (University of Maryland Medical Center, 2010). Cryptococcal infections can broadly be categorized into 3 types based on the location of their incidence:
  1. Cutaneous cryptococcosis
  2. Pulmonary cryptococcosis
  3. Cryptococcal meningitis
Amongst all the three types of cryptococcal infections mentioned here cryptococcal meningitis is the most serious and life threatening. It is a subacute meningoencephalitis in which the meninges of the brain get infected which is probably an outcome of the dissemination of a previous pulmonary infection (Park., et al. 2009). It targets mainly the people having compromised immune system due to HIV infection, immunosuppressive drugs, undergoing chemo or radiotherapy, organ transplant, etc (Durski., et al. 2013; Zhu.,  et al. 2010). Amongst these, the people infected with HIV are most susceptible to cryptococcal meningitis accounting for 95% of cases in middle- and low-income countries (MLICs) and 80% of cases in high-income countries (HICs) (Pyrgos., et al. 2013). Additionally, the data at hand related to the fatality rate portrays 9% in high-income regions, 55% in low/middle-income regions, and a whopping 70% in sub-Saharan Africa showing the seriousness of this infection. Furthermore, in 2009, 958,000 cases of the said infection 625,000 deaths associated with this infection were registered (Park., et al. 2009).
Symptoms, Diagnosis and Therapy
Symptoms of this infectious disease are diverse, involving fever, blurred vision, fatigue, dry cough, headache and confusion (Barron and Medinger, 2008). These symptoms are progressive and gradually increase as the time elapses.
The confirmation of the presence of cryptococcal antigen in the body can be made by testing the cerebrospinal fluid, urine and sputum. The most definitive method to identify the meningitis infection is the culture of CSF and checking on the parameters such as elevated white cell counts, with a high proportion of lymphocytes, elevated CSF proteins and low CSF glucose. Traditional method utilized India ink which was low in sensitivity. It was replaced by new techniques such as latex agglutination test, lateral flow immune chromatographic assay (LFA), enzyme immune assay etc (Williamson., et al. 2017).
The treatment of cryptococcal meningitis involves three phases: an initial 2-week induction therapy dependent on fungicidal amphotericin B-based regimen, followed by 8-week consolidation therapy and subsequently maintenance therapy with fluconazole, continued for 6-12 months and/or until restoration of host immunity.
Induction Antifungal Therapy
Induction antifungal therapy comprises of a combinatorial treatment of amphotericin B (0.7-1.0 mg/kg per day) and flucytosine 100mg/kg/day for a period of two weeks. (Abbasi., et al. 2015; Perfect., et al. 2010). This combination therapy has been seen to result in around 40% reduced mortality rates in the initial 10 weeks. Combination therapy with amphotericin B and flucytosine was associated with a ~40% lower hazard of mortality at 10 weeks. Additionally, this therapy had a sustained effect for around 6 months and also it was responsible for the augmented rate of fungal clearance on comparison with amphotericin B monotherapy. Apart from this, on unavailability of flucytosine a treatment regimen utilizing amphotericin B and fluconazole or voriconazole has also been recommended (Perfect., et al. 2008; Loyse., et al. 2011).
Consolidation and Maintenance Therapy
The consolidation therapy is generally individualized, in other words, varying from individual to individual and depending upon the effect of the induction therapy on an individual. According to the current guidelines, consolidation phase therapy should commence after 2 weeks of induction therapy and involve the administration of fluconazole (400–800 mg/day) for at least 8 weeks (Perfect., et al. 2008). Further, maintenance therapy is initiated after successful completion of the induction and consolidation therapy, in which fluconazole is administered at a dosage of 200 mg/day.
Conclusion
Cryptococcal meningitis is one of the lethal fungal infections especially in case of immunosuppressed patients. Therefore, new techniques for the diagnosis and novel therapeutic approaches are required for the better management of this disease.
References
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Citation: Neelabh and Karuna Singh. “Cryptococcal Meningitis: A Lethal Fungal Infection”. Clinical Biotechnology and Microbiology 2.3 (2018): 371-373.
Copyright: © 2018 Neelabh and Karuna Singh. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.