A survey of dermatophytes isolated from human patients in the United States from 1979 to 1981 with chronological listings of worldwide incidence of five dermatophytes often isolated in the United States

Dermatomycoses and their etiology in the material of the Dermatological Department in Lódź, Poland

In the period of 1982-1988 mycological examinations were carried out on 4,657 patients suspected of having dermatomycoses. In approximately 60% of patients infections were localized on the feet and hands and in approximately 30% other regions of the glabrous skin were involved. Before treatment, 5,725 examinations were made. The diagnosis was confirmed mycologically in 30% of the cases, most often in tinea cruris (51%) and chronic paronychia (60%). In more than half of the cases the isolated fungi were dermatophytes, the most frequent species being Tr. mentagrophytes, followed by Tr. rubrum and E. floccosum. Among the other fungi, more than 50% were C. albicans and other Candida species.

Infections caused by Trichophyton raubitschekii: clinical and epidemiological features

Thirty-eight cases of human infection with the recently described dermatophyte species Trichophyton raubitschekii were studied and a description is presented of the clinical and epidemiological features of infection with this organism. Results revealed the usual preponderance of males (2:1) but a high proportion of individuals of Asian origin (60.5%) in the infected population. Tinea corporis, tinea cruris and tinea pedis were the most common infections. T. raubitschekii differed significantly from the more common Trichophyton rubrum and T. mentagrophytes in being more strongly associated with tinea corporis. Some T. raubitschekii infections produced inflammatory lesions while others clinically resembled those caused by the related species T. rubrum and T. mentagrophytes. T. raubitschekii could be distinguished from related species by means of special mycological procedures in the laboratory.

Superficial mycoses observed at the Department of Dermatology of the University of Pavia. A 13-year survey

Over a period of 13 years, 4,100 specimens were cultured for fungi. Pityriasis versicolor (Malassezia furfur) was demonstrated in 17.6%, dermatophytosis in 34.6% and candidiasis in 10.8%. The most frequently isolated strains were M. canis (31.5%), T. rubrum (26.3%), E. floccosum (19.7%), T. mentagrophytes (19.3%) for the dermatophytes and C. albicans (88.9%). Those rarely seen were: M. gypseum, T. violaceum, M. audouini, T. schoenleinii. We observed the absolutely complementary results of the microscopic examinations and the cultures of the specimens.

Immunoregulation of dermatophytosis

Dermatophytoses are superficial infections caused by a group of fungi, the dermatophytes, which invade keratinized tissue of skin, hair, and nails in humans and animals. The importance of normal immune function in resistance to dermatophytoses is substantiated by an increased susceptibility to chronic infection seen in patients with impaired immunological responses. Humoral and cell-mediated immunities are both elicited during the infection. However, specific antibodies to dermatophytes do not seem to play a major role in protective immunity. On the other hand, the development of cell-mediated immunity during the infection is critical in eliciting resistance to the disease. For instance, resolution of the disease in both naturally and experimentally infected humans and animals correlates with the development of delayed-type hypersensitivity (DTH), whereas persistence of infection is frequently accompanied by poor in vitro blastogenic response and absent DTH. Furthermore, in experimentally infected mice, immunity to dermatophyte infection can be achieved by adoptive transfer of lymphoid cells, but not by serum, of infected donors. The present review includes an overview of published work and current research on the cellular events implicated in immunity to dermatophytosis. The role of humoral factors in such immunoregulation is also discussed.

An outbreak of Trichophyton tonsurans dermatophytosis in a chronic care institution for the elderly

A nosocomial outbreak of dermatophytosis caused by Trichophyton tonsurans var. sulfureum subvar. perforans is reported in a nursing home for the elderly. The outbreak affected six residents and persisted for nine months despite remedial medical and sanitary measures. In a survey designed to determine the potential role of fomites in disease transmission, 129 environmental sites were sampled. A high proportion (22.3%) of the samples yielded T. tonsurans, including samples from beds, floors, and washroom facilities. Methods for the control of dermatophyte outbreaks in chronic care institutions are discussed.

Itraconazole therapy for recalcitrant dermatophyte infections

Five patients with recurrent Trichophyton rubrum infections had become unresponsive to topical and oral antifungal therapy. These patients were treated in an open trial of itraconazole, a new oral antifungal medication. Each patient responded promptly to therapy within 1 month and showed marked improvement at the end of 3 to 6 months of therapy. Complete clearing of toenail infections was not achieved in this limited trial and recurrences occurred in the four patients who had toenail infections. The drug was well tolerated and no adverse effects were observed. Itraconazole appears to be an effective drug for relief of clinical aspects of recalcitrant dermatophyte infections. Long-term safety and prevention of recurrence remain to be established.

Tinea corporis caused by Microsporum canis: report of a nosocomial outbreak

In an unusual nosocomial outbreak, 13 staff and 11 patients in an acute and chronic health care facility were infected with the zoophilic dermatophyte, Microsporum canis. The dermatophyte was apparently introduced into the facility by a single infected patient. Likely modes of subsequent disease transmission include person-to-person contact, handling of contaminated laundry, and use of a shared razor. Infection control measures for managing such outbreaks are discussed.

A survey of dermatophytes isolated from human patients in the United States from 1982 to 1984

A survey of dermatophytes isolated from patients seeking medical advice was made from 1982 to 1984 in the United States. The survey included 59 locations with data from 49 cities and one state. Listing of the isolated dermatophytes and the frequency given by percentage of total follows: Trichophyton rubrum 46.8%, T. tonsurans 33.3%, T. mentagrophytes 10.1%, Microsporum canis 4.5%, Epidermophyton floccosum 3,5%, M. gypseum and T. verrucosum both 0.7%, M. audouinii and T. terrestre both 0.1%, and T. violaceum 0.06%. No isolations of M. ferrugineum or T. schoenleinii were reported. Temporal increases were observed for frequencies of T. mentagrophytes, T. tonsurans and M. canis, and decreases occurred for frequencies of E. floccosum and T. rubrum when the data from this survey were compared by the goodness of fit test to data of the 1979 to 1981 survey. The percent of dermatophyte isolations identified as T. tonsurans correlated significantly with the percentage of blacks in cities of 100,000 or more people.

Ecology of dermatophyte infections in South Bronx, New York, 1969 to 1981

This survey describes the ecology of superficial dermatophyte infections in South Bronx, New York from 1969 to 1981. The predominant species were Trichophyton rubrum (Castellani) Sabouraud, 1911 (57.5%), followed by Trichophyton tonsurans Malmsten, 1845 (18.5%), Trichophyton mentagrophytes (Robin) Blanchard, 1986 (11.5%), Microsporum canis Bodin var. canis Matsumoto, Padhye, and Ajello, 1902 (5%), Epidermophyton floccosum (Harz) Langeron and Milochevitch, 1930 (3.9%), and M. audouinii Gruby, 1843 (2.8%).

Tinea capitis caused by Trichophyton tonsurans

Children with tinea capitis caused by Trichophyton tonsurans often have a lifetime of association with the organism and, in spite of intermittent therapy, as adults pass the infection to successive generations. While most current treatment regimens are directed at treating the individual patient, our study supports the need to evaluate and possibly treat all family members and their home environment.

The changing epidemiology and emerging patterns of dermatophyte species

The anthropophilic agents of tinea capitis are being eradicated from their historic areas in developed and developing nations. The one exception is T. tonsurans in the United States and Canada. In these nations, the infections are increasing among black children, probably because of hair style and hygiene habits. Elsewhere in the world, M. canis has become or is becoming the dominant agent of tinea capitis. Tinea corporis reflects either the dominant agent of tinea capitis or the sphere of T. rubrum. Trichophyton rubrum is the most common agent worldwide of crural and pedal disease and often tinea corporis. The other anthropophilic species, T. mentagrophytes var. interdigitale and E. floccosum, are also firmly established, but as a distant second and third. These five species account for most ringworm worldwide. Other species are of lowlevel infection, are rare, are locally endemic, or--in the case of some anthropophiles--are dying out. The only evidence of active evolution among the dermatophytes is seen in M. canis and T. mentagrophytes. In both, host-specific strains have emerged and will probably separate as species. This probably has happened already in the case of the variety interdigitale of T. mentagrophytes.