**2.1 Methods of pathogen transmission – a short description**

Dermatophytes are keratinophilic fungi, which parasitize on corneous structures, such as stratum corneum, hair or nails (Kobierzycka et al., 2005). Dermatophyte species are equipped with numerous enzymes, enabling them to survive on the skin and its appendages, because they have a proteolytic, keratinolytic and lipolytic activity. Furthermore the skin environment is conducive to dermatophytes because the corneal layer lacks blood vessels making it difficult to contact with immunologically competent cells and activate the defense mechanisms. On the surface of the epidermis are proteins, carbohydrates and micronutrients (including iron ions), which may provide substrates for the metabolism of fungi and help them to survive. Of great importance may also be some specific anatomic regions of the skin, greatly facilitating the colonization by fungi. Scalp hair can therefore arrest arthrospores spreaded by air. Similarly, spores are arrested in the hyponychium under or in the interdigital spaces, or in the folds of the skin where additionally oclusion helps them to develop (Dworacka-Kaszak, 2004). The spores are particularly resistant to environmental conditions, such as variable temperature and drying (Hryncewicz-Gwozdz et al., 2005; Kobierzycka et al., 2005). It is known that they can survive outside the host organism and colonize the skin and its appendages under favorable conditions, for example, in warm and humid environment, with increased amounts of CO2, which prevails in the poorly sheered shoes, it can lead to growth of the fungi and invasion of the skin structures.

To narrowly understand epidemiology of dermatomycoses, methods of pathogen transmission, are described below.

The sources of dermatophyte fungi infection are: human, animals and soil.

Infection with antropophilic dermatophytes may happen through direct contact with infected person, moreover spores of dermatophyte fungi can survive on skin and its

Epidemiology of Dermatomycoses in Poland over the Past Decades 35

 *Tinea corporis* – infection of the trunk and also extremities. Caused by antropophilic, zoophilic and geophilic species. Fungi, after infection of the skin form colonies and grow centrifugally. Lesions caused by antropophilic species form round or oval patches, which are spreading peripherally, and resolving and disappearing in the middle. In the part of the peripheral states moderate inflammation, redness and slight swelling, and even the production of pustules is seen. Lesions caused by zoophilic species characterize with significant inflammation, are well separated from the healthy skin, with exfoliation on the whole surface. Lesions are very often accompanied with

 *Tinea barbae* – infection of the bearded area of men. Mostly it is caused by zoophilic species. Generally, the infection occurs as a follicular inflammation, or as a cutaneous granulomatous lesion, i.e. a chronic inflammatory reaction. It is one of the causes of folliculitis. Lesions are accompanied with itching. This infection is most common in

 *Tinea faciei* – infection of the glabrous skin of the face. It is caused by antropophilic and zoophilic species. Itchy lesions appearing on the face may be erythematous with exfoliation in the peripheral part or they may proceed with significant inflammation

 *Tinea pedis* – infection of feet and the interdigital spaces. Mostly it is caused by antropohilic species. In the interdigital variety, lesion appear in the folds between 3rd and 4th toes. The lateral surfaces of the toes and the bottom of folds are covered with layers and scales of keratinized epidermis. In the depth of the fold may appear cracks of the skin. Lesions may proceed on the dorsal and the basal surface of toes. There is a slight redness and exfoliation of the skin, and sometimes tiny vesicles and pustules may appear. The course is usually chronic, but it may be subject to intensify. On the plantar surface of feet occur eruptions similar to eczema. There are itchy follicles of various sizes. The course is chronic and recurrent, sometimes severe, however,complicated by

 *Tinea manuum* – fungal infections of hands, it is caused by antropophilic species. Fungal infection of hands is almost always secondary to athlete's foot. Very rare primary form may develop in the case of occupational exposure to dermatophytes. Dermatophyte infections of hands can take several different clinical forms. The most commonly occurring is hiperkeratotic form, which is characterized by excessive keratosis of hands skin, with the presence of small and very adherent scales on erythematous base. Infectious process is typically subject to the fingertips. Also often

 *Tinea cruris* - dermatophyte infection of the groin, caused mostly by antropophilic species. In many patients the development of groin ringworm occurs through auto-infection from

purulent secondary infection and secondary prone to allergization.

coexists nail fungal infection. Less common is intertrigous form.

foci formation. Lesions very often are accompanied with itching.

itching.

farmers.

with the exfoliation on the entire surface.

diverse and in some individuals may it be a slight erythema. In extreme cases, the changes are soft with the presence of pustules and inflammatory tumors with pus or yellow crusts. This condition is called deep mycosis (kerion) and is the result of an inflammatory response to the presence of the fungus. Apart from very severe forms of deep fungal infection of the scalp, hair loss is usually transient. Even in the worst cases, regrowth occurs at a surprisingly high proportion. Exception is infection with antropophilic *Trichophyton schoenleinii*, which leads to scarring and permanent alopecia

appendixes without causing the disease (asymptomatic carrier) (Adamski & Batura-Gabryel, 2007).

Infection may occur also through some objects on which infectious material can be found (stratum corneum or hair with spores of fungi). The source of trunk, groin or extremities infections may be clothes, underwear or towels and sponges. Scalp diseases may happen through using the same brushes or combs. Shoes, socks, accessories for feet care or cosmetic pedicure are often the source of infections of feet and toenails.

Nails diseases are often connected with cosmetic manicure, infection may be a result of unsuitable disinfection of nails care accessories in cosmetic salons.

Also some public places could be potential source of antropophilic dermatomycoses – for example swimming-pools, toilets, showers, hotels, schools and similar (Bolinski et al., 2003, Szepietowski & Baran, 2005).

Recently some cases of *tinea corporis gladiatorum* were described in literature. This type of dermatomycosis is common among wrestlers and judo competitors. The source of infection are athletes and wrestling mats (Hryncewicz-Gwozdz et al., 2011).

Similarly with zoophilic species – transmission of pathogen may happen through direct contact with an infected animal or animal being carrier of fungus. Zoophilic dermatophytes can be also transmited from human to human. The source of infection in children and adults are mostly domestic animals – cats, dogs, hamsters, guinea pigs, rabbits or even some birds. Farmers also often suffer from dermatomycoses transmitted from breeding cattle (pigs, cows, sheep, horses, goats) (Adamski Z & Batura-Gabryel H., 2007).

Infection with geophilic dermatophytes usually happens as a result of contact with soil and it is common among people, who cultivate the soil (gardeners, farmers). The disease more often affect males than females. Working without protective gloves and unsuitable hygiene is conductive for transmission of pathogen. In literature were also described cases of transmission of geophilic dermatophytes through some animals (for example monkeys, mouses, leopards, rats, tigers) and insects (flies). Infection through direct contact with ill peoples occurs rather rarely (Kalinowska et al., 2009b)
