Medical Mycology: Open Access

Short Communication

Mycology is a science that is open to developments and innovations in the medicine and scientific areas. Fungi have taken place much more than bacteria in the Medicine with increasing the number of immunocompromised patients who are treated due to onco-hematological diseases and autoimmune diseases. However, fungi do not commonly come to all physicians’ mind as a disease cause. This situation leads to delays in the diagnosis and treatment of fungal infections. It is becoming apparent on the agenda that fungi other than Candida species cause infections with serious morbidity and mortality. Therefore, when, what, who, and why questions in terms of fungal infections need to remind to physicians to ask.

Who are at Risk for Invasive Fungal Infections?

If a patient who has one those factors, including central venous catheter, urinary catheter, comorbid conditions, total parenteral nutrition, surgery, especially intraabdominal surgery, transfusion, mechanic ventilation, broad-spectrum antibiotic use, oncohematological diseases, allogeneic haematopoietic stem cell transplantation (HSCT), immunosuppressive therapy, hypoalbuminemia, recipients of solid organ transplants (SOT), and APACHE II score (≥ 16), physicians should take into consideration fungal infections in line with patient’ s signs, symptoms and other diagnostic findings [1].

Which Antifungal Drug Should be Chosen?

Antifungal drug should be chosen taking into consideration severity and underlying disease of the patient, antifungal resistance status in health care setting of local area, interactions with other drugs, presence of organ failures, probable or possible fungal pathogen. In the non-neutropenic, severe patients, an echinocandin should be considered initially. If a fluconazole-susceptible Candida spp. yields in the blood culture, fluconazole is switched once the patient becomes clinically stable. Voriconazole should be the preferred treatment option with Amphotericin B being an alternative for Aspergillosis in patients with allogeneic HSCT recipients, patients receiving induction chemotherapy for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS), and those undergoing immunosuppressive therapy for graft-versus-host disease after allogeneic HSCT [1]. C. parapsilosis candidemia is related to vascular catheters and parenteral nutrition [2]. C. tropicalis is commonly related to cancer and neutropenia. C. krusei and C. glabrata fungemias are related to previous exposure to azoles [3].

Caspofungin and liposomal amphotericin B deoxycholate (LAmB) should be opted as first and second choice of antifungal drug for the empirical treatment of persistently febrile neutropenia, respectively [1]. Mucormycosis is an angioinvasive infection caused by Mucorales (Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Cunninghamella and Saksenaea), and related to risk factors, including immunocompromising states such as haematological malignancy, solid organ transplantation, diabetes mellitus with or without ketoacidosis, bone marrow or peripheral blood stem cell transplantation, corticosteroids, neutropenia, and deferoxamine therapy for iron overload [4].

Why should the Fungal Isolate be tested for Antifungal Drug Susceptibility?

Aspergillus isolates should be tested for antifungal drug susceptibility, if patient is suspected to have an azole-resistant isolate or unresponsive to antifungal agents, or for epidemiological purposes. Routine antifungal susceptibility testing is not recommended for isolates recovered during initial infection. If there is an increase in the azole-antifungal drug use, or considerable azole resistance rates in the isolated fungal strains at a health care setting or local area, antifungal resistance should be evaluated [5].

How should Galactomannan be used for the Diagnosis of Aspergillosis?

Serum and BAL galactomannan (GM) is recommended for the diagnosis of IA in adult and pediatric patients. GM is not recommended for routine blood screening in patients who receive mold-active antifungal therapy or prophylaxis. However, bronchoscopy specimens can be tested for those patients. SOT recipients or patients with chronic granulomatous disease are not recommended for GM screening [5].

What is the Value of the Radiographic Diagnosis in Invasive Aspergillosis?

Magnetic resonance imaging (MRI) has no additional benefit compared to CT scanning for early diagnosis of invasive pulmonary Aspergillosis, but is the preferred imaging modality to ascertain and illustrate osseous, paranasal sinus lesions, or CNS disease [6-8].

When is it Harmless to Continue with Chemotherapy or Transplantation in a Patient with Invasive Aspergillosis?

Invasive Aspergillosis is not an absolute contraindication to further chemotherapy or HSCT. Decision should be dependent on the risk of progressive aspergillosis during periods of following antineoplastic treatment versus the risk of death from the underlying malignancy [5].

References

1. Ruping MJGT, Vehreschild JJ, Cornely OA (2008) Patients at high risk of invasive fungal infections: when and how to treat. Drugs 68: 1941.
2. Clark TA, Slavinski SA, Morgan J, Lott T, Arthington-Skaggs BA, et al. (2004) Epidemiologic and molecular characterization of an outbreak of Candida parapsilosis bloodstream infections in a community hospital. J Clin Microbiol 42: 4468-4472.
3. Bassetti M, Ansaldi F, Nicolini L, Malfatto E, Molinari MP, et al. (2009) Incidence of candidaemia and relationship with fluconazole use in an intensive care unit. J Antimicrob Chemother 64: 625-629.
4. Prabhu RM, Patel R (2004) Mucormycosis and entomophthoramycosis: a review of the clinical manifestations, diagnosis and treatment. Clin Microbiol Infect 10: 31-47.
5. Patterson TF, Thompson GR, Denning DW, Fishman JA, Hadley S, et al. (2016) Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis 63: e1-e60.
6. Blum U, Windfuhr M, Buitrago-Tellez C, Sigmund G, Herbst EW, et al. (1994) Invasive pulmonary aspergillosis. MRI, CT, and plain radiographic findings and their contribution for early diagnosis. Chest 106: 1156-1161.
7. Gabelmann A, Klein S, Kern W (2007) Relevant imaging findings of cerebral aspergillosis on MRI: a retrospective case-based study in immunocompromised patients. Eur J Neurol 14: 548-555.
8. Siddiqui AA, Bashir SH, Ali Shah A (2006) Diagnostic MR imaging features of craniocerebral aspergillosis of sino-nasal origin in immunocompetent patients. Acta Neurochir (Wien) 148: 155-156.