Fungal Infections in Humans

Abstract

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.

Diagnóstico micológico: de los métodos convencionales a los moleculares

“…Los hongos son microorganismos de distribución mundial con una diversidad que puede oscilar entre 600.000 y 700.000 especies en la naturaleza [7,8], de las cuales aproximadamente 200, y con tendencia a aumentar, pueden producir enfermedades en el hombre [9][10][11]. Las infecciones causadas por hongos comprenden desde micosis superficiales, las cuales son comunes y relativamente fáciles de curar, hasta sistémicas e invasivas, que pueden amenazar la vida de las personas [12] debido, principalmente, a las condiciones de las poblaciones que afectan y a las dificultades para realizar el diagnóstico.…”

“…Los síntomas y los signos de estas infecciones son variados y dependen del agente etiológico, la localización de la misma y el estado inmune del hospedero. En escasas ocasiones la historia personal y los hallazgos del examen físico son suficientes para establecer el diagnóstico de una infección fúngica [10,68]; no obstante, las infecciones fúngicas suelen confundirse con las producidas por bacterias, por lo que establecer el contexto en que se producen es lo que permite sospecharlas [68].…”