Fungi are good at adapting to their environmental conditions. Nevertheless, they usually prefer a certain environment. They particularly like it moist, warm and dark. Particularly in Europe, they usually do not trigger an infection until there is prior damage, disease, or immune deficiency in the host. This is technically referred to as “facultative pathogenic”.
However, in other latitudes such as Africa or South America, aggressive fungal species such as histoplasmas are also found that cause disease even in healthy individuals (“obligate pathogenic”).
Local mycoses and systemic mycoses
Roughly, two forms of fungal infections can be distinguished: First, the more superficial local mycosis of skin and mucous membranes, and second, systemic mycosis, i.e., infestation of internal organs:
- Local mycoses: the most common representative is athlete’s foot and nail fungus (mainly caused by dermatophytes). It is transmitted from person to person, usually by spores in the small skin flakes that everyone sheds. That is why you get infected particularly often where you walk barefoot and where there is a climate that is pleasant for fungi, i.e. swimming pools, saunas and (hotel) showers. Particularly at risk are people with pre-damaged skin or immune deficiency.
- Systemic mycoses: Systemic mycosesare triggered by yeast or mold fungi and often affect the gastrointestinal tract, lungs or even the brain.
The most common types of systemic mycoses
Most common in Europe are:
- Candida albicans: In about half of the population, these yeasts can be detected in the gastrointestinal tract. If the defense is weakened, they can spread and cause discomfort. The clinical picture is also known as thrush. People at risk are, for example, diabetics, patients with intestinal diseases or people who have to take certain medications (some antibiotics, cortisone). In the infested areas show white coatings – for example, in the mouth and throat, in the esophagus, in the vagina or – in infants – in the diaper area.
- Aspergillus (“ray fungus”) forms toxins in moldy food (aflatoxins), triggers, for example, in AIDS patients severe clinical pictures. The disease also occurs more frequently after bone marrow and organ transplants or in leukemia. There is a risk of fungal sepsis, so a flooding of the entire organism with the pathogens present in the blood.
- Cryptococcus neoformans is widespread, especially in bird droppings and potting soil, is inhaled with the dust and can spread throughout the body, especially in the brain, in the seriously ill.