THE EPIDEMIOLOGY OF ANIMAL RINGWORM IN MAN

Tinea corporis caused by Trichophyton equinum transmitted from asymptomatic dogs to two siblings

Each year, millions of people worldwide are affected by superficial mycoses, which are frequently caused by dermatophytes having affinity to the scalp, nails, hair and the stratum corneum of the skin. The changing reservoirs of zoophilic dermatophytes, the numerous reports of animal carrier status, and the increasing number of pets make the diagnosis difficult, which is usually impossible based only on medical history. Herein we present a case report of tinea corporis caused by Trichophyton equinum in siblings who had no contact with horses. The routine laboratory diagnostic procedures for identification of isolates were based on phenotypic and genotypic characteristics, especially molecular techniques using rDNA internal transcribed spacer sequences. The results showed that both techniques proved to be insufficiently discriminatory to differentiate two closely related species, i.e. Trichophyton equinum and Trichophyton tonsurans. Introduction of a TEF1 sequence analysis to the diagnostic procedures revealed consistent differences between these two species and facilitated unambiguous identification. Interestingly, dogs that could leave the homestead freely were the source of the infection in children. In conclusion, Trichophyton equinum was considered in the past as a strict zoophilic dermatophyte associated with horses and rarely transmitted to humans. This study revealed that this species can have other reservoirs and live in the fur of asymptomatic animals.

Tinea corporis caused by Trichophyton equinum in a rider and review of the literature

BACKGROUND

Trichophyton equinum is a zoophilic dermatophyte usually causing ringworm in horses. Cases of skin infections in humans are very rare. CASE REPORT : ​We describe a case of tinea corporis caused by T. equinum on a buttock of a rider who often rode bareback with short trousers.

CONCLUSION

Although T. equinum was considered in the past as a strict zoophilic dermatophyte, our case report confirms that it can cause dermatophytoses also in humans. A review of epidemiological and clinical features of human infections caused by T. equinum is presented.

Fungi Isolated From House Flies (Diptera: Muscidae) on Penned Cattle in South Texas

Musca domestica L. were collected from cattle diagnosed with bovine ringworm to evaluate the potential of the house fly to disseminate Trichophyton verrucosum E. Bodin, a fungal dermatophyte that is the causative agent for ringworm in cattle. Fungal isolates were cultured from 45 individual flies on supplemented Sabouraud dextrose agar, and isolates were identified using morphological and microscopic approaches. Each isolate was identified further by PCR amplification of the ribosomal DNA locus with fungal-specific primers and subsequent amplicon sequencing. Trichophyton verrucosum was not identified using these approaches. However, 35 different fungal species representing 17 genera were cultured from collected flies, including several species that are allergenic and pathogenic to humans and animals. Several species within the fungal orders Hypocreales, Microascales, Onygenales, Saccharomycetales, Xylaniales, and Agaricales were observed for the first time on house flies. The most frequent fungus recovered was Cladosporium cladosporoides Fresen, which is known to be a ubiquitous, airborne allergen to humans.

Terbinafine treatment of Trichophyton equinum infection in a child

A case of tinea faciae caused by Trichophyton equinum affecting a 5-year-old boy is described. The boy had ridden a pony a month earlier and responded to a 6-week course of treatment with oral and topical terbinafine.

[Dermatophytoses in the urban environment and the coexistence of man with dogs and cats]

There have been submitted to clinical exam in laboratory of dermatophytosis and inquired about possible contact with domestic animals (dogs and cats) 158 patients living in the urban area of Fortaleza, that showed lesions suspected of dermatophytosis. This search associated to the obtained data in questionnaires permitted us to identify the frequency of domicile outbreaks. Within the 83 people with dermatosis isolated of human infections, prevailed the anthropophilic species over the zoophilic ones, and that it was observed a confluence of human and animal diagnosis in 100% of the human dermatophytosis zoophilic cases, where the same species were identified in men and contacting animals: M. canis and T. mentagrophytes. As the patients carrying anthropophilic dermatophytosis varied as to the contact with animals, not having been these fungus isolated from none of the contacting animals. Before the low frequency of zoophilic dermatophytosis, it was considered that the intimacy of men with domestic dogs and cats represented was little as a conditional factor of occurrence of dermatophytosis in the urban environment.

Human Trichophyton equinum infection treated with terbinafine

A case of tinea capitis caused by Trichophyton equinum is described. This responded to a 6-week course of treatment with the allyl amine antifungal agent, terbinafine.

Onychomycosis caused by Trichophyton equinum

A case of onychomycosis caused by Trichophyton equinum affecting the right thumbnail of a 13-year-old girl is described. Trichophyton equinum appears to be an extremely rare cause of nail infection.

Studies on fungal flora in hair from domestic and laboratory animals suspected of dermatophytosis. I. Dematophytes

Hairsamples of domestic and laboratory animals suspected of dermatophytosis were examined for the presence of dermatophytes. A nutritionally poor base-medium developed by the author was successfully used in the isolation and identification of dermatophytes. Casein-medium supplemented with vitamins and Sabouraud-liquid medium were used in special cases. Dermatophytes were isolated in 36 of 331 samples (10.9%). The dermatophytes recovered were Microsporum canis: 13 isolates from cat. 4 from dog. 1 from horse; Trichophyton mentagrophytes var. granulare: 3 isolates from dog, 3 from horse, 2 from guinea pig and 1 from rabbit; Trichophyton terrestre 1 isolate from dog. Eleven of the 13 feline isolates originated from house cats and the relative frequency was higher among the purebred cats. Two of the cat isolates were connected with human dermatophytosis.

Epidemiologic study of dermatophytoses in Salamanca (Spain)

An epidemiologic study of the dermatophytoses in Salamanca (Spain) from 1973 to 1976 was performed. Dermatophyte species were identified in 224 patients with clinical tinea infections; 31 bovines, 18 rodents and 70 soil samples. The prevalence of Trichophyton verrucosum and Epidermophyton floccosum was strikingly high in relation to other statistics. The most common clinical forms were tinea corporis and tinea cruris. Tinea capitis by anthropophilic species was uncommon.

[Study of the contamination by dermatophytes of a population of small wild mammals in Alsace]

Mature fruit-bodies of Coprinus congregatus grown on modified Bille-Hansen medium were obtained with concentrations of glucose ranging from 5 to 40 g/l and asparagine from 0 to 4 g/l; the carbon/nitrogen ratio varying from 13 to 100. When the ratio C/N is too high (above 100), no visible primordium is formed; when this ratio is under 13, numerous primordia are produced, but they never reach maturity. A positive correlation exists between the C2/N ratio and the time required for producing mature fruit-bodies. The best yield for basidiocarps production is reached when the C/N ratio value is around 30 and glucose concentrations range from 10 to 20 g/l.