Fungal Infections in Humans


Fungi are pathogenic to humans and cause a variety of diseases in normal and immunocompromised hosts. Fungi can exist as filamentous/mould or yeast form, both forms are able to cause infections in human host. Dimorphic fungi, that is, Histoplasma capsulatum also exist and can grow as a filamentous form at room temperature and yeast at body temperature. Fungi can infect any part of the human body including hairs and nails and depending upon their level of penetration is divided into four groups, superficial mycoses, cutaneous mycoses, subcutaneous mycoses and systemic/deep mycoses. Systemic mycoses are often fatal without treatment. Ability to maintain constant body temperature is the natural defence against pathogenic fungi. In the event of infection, accurate diagnosis and often the combination of different treatment modalities are required for a successful treatment.

Key Concepts:

  • Fungal infections represent the invasion of fungi in tissue.

  • Only 200 fungal species are able to cause infection to human host, of these only 20–25 species commonly cause infection.

  • Fungi appearance is either hyphae (known as mould) or yeast. Few are dimorphic and change from one state to other depending on the temperature conditions.

  • Fungi can cause superficial to deeper infections to human host.

  • Most of the fungal infections are opportunistic and do not need the human host for survival.

  • Most fungal infections are airborne and acquired by inhalation or contact of air, soil or surfaces contaminated with spores.

  • Causes more damage to immune‐suppressed patients, that is, organ transplant recipients and AIDS patients.

  • Diagnosis is made usually by using simple tests that include microscopic stains, culture and Antibody/antigen tests, in some cases imaging can be helpful for deep‐seated infection diagnosis.

  • Fungal infection commonly caused by normal flora so the reoccurrence rate is higher than other infection

  • Allylamines, antimetabolites, azoles, glucan synthesis inhibitors, polyenes, echinocandins and others are the drugs used to cure fungal infections.

Keywords: mycoses; fungus; antifungal therapy; opportunistic; yeast; mould


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Further Reading

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Jain, Neena, and Fries, Bettina C(Sep 2011) Fungal Infections in Humans. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0002234.pub2]