[Epidemic of Trichophyton tonsurans tinea capitis in a nursery school in the Southern suburbs of Paris]

An outbreak of trichophytic tinea capitis in a group of schoolchildren in a rural area of the department of Cauca, Colombia

Introduction. Tinea capitis is a mycosis of keratinized tissue, which affects the scalp and may cause alopecia, pruritus, and desquamation. This type of mycosis is more frequent in school-age children, and it may represent a public health problem; the main etiological agents reported for Colombia are zoophilic dermatophytes. Objective. To characterize an outbreak of Tinea capitis in 32 children from a rural school in the department of Cauca. Materials and methods. We conducted an epidemiological field study using a structured survey to characterize sociodemographic aspects and predisposing factors for this mycosis. We collected samples of affected scalp scales and hair for mycological studies. The children and the general population received recommendations, about these mycoses’ prevention, from Cauca’s health authorities and the local hospital. The parents verbally approved the informed consent. Results. The etiological agent isolated in 63% of the collected samples was Trichophyton tonsurans, an anthropophilic dermatophyte, and the main predisposing factor was sharing razors (87.5%). Conclusions. Ideally, mycological studies define the etiological agent to propose therapeutics and recommendations in agreement with management guidelines. Implementation of multidisciplinary measures to control the outbreak and educate the population is required.

Human adaptation and diversification in the Microsporum canis complex

The Microsporum canis complex consists of one zoophilic species, M. canis, and two anthropophilic species, M. audouinii and M. ferrugineum. These species are the most widespread zoonotic pathogens causing dermatophytosis in cats and humans worldwide. To clarify the evolutionary relationship between the three species and explore the potential host shift process, this study used phylogenetic analysis, population structure analysis, multispecies coalescent analyses, determination of MAT idiomorph distribution, sexual crosses, and macromorphology and physicochemical features to address the above questions. The complex of Microsporum canis, M. audouinii and M. ferrugineum comprises 12 genotypes. MAT1-1 was present only in M. canis, while the anthropophilic entities contained MAT1-2. The pseudocleistothecia were yielded by the mating behaviour of M. canis and M. audouinii. Growth rates and lipase, keratinolysis and urea hydrolytic capacities of zoophilic M. canis isolates were all higher than those of anthropophilic strains; DNase activity of M. ferrugineum exceeded that of M. canis. The optimum growth temperature was 28 °C, but 22 °C favoured the development of macroconidia. Molecular data, physicochemical properties and phenotypes suggest the adaptation of zoophilic M. canis to anthropophilic M. ferrugineum, with M. audouinii in an intermediate position.

Continuous increase of Trichophyton tonsurans as a cause of tinea capitis in the urban area of Paris, France: a 5-year-long study

Tinea capitis (TC) is a highly contagious fungal infection of the scalp due to dermatophytes in children. To obtain information on the epidemiology of TC in the urban area of Paris, we analysed the microbiological results of 3090 patients seen with suspected TC from October 2010 to September 2015 at Saint Louis hospital, Paris, France. A peak of TC was observed in 3-6 year-old children, followed by a progressive decrease until 16 years of age. Of the 1311 positive cultures, 95% (1246) yielded one of the three anthropophilic species [Trichophyton tonsurans (33.5%), Trichophyton soudanense (38.3%), or Microsporum audouinii (28.2%)]. When considering one TC case per family, we observed a significant increase of T. tonsurans (P = .018) during these 5 years. The increase was more pronounced (P = .0047) in patients of West-African descent (n = 666), and was at the expense of M. audouinii and T. soudanense. On the other hand, the Caribbean patients (n = 85) remained predominantly (72.9%) infected by T. tonsurans. Our results show a better virulence of T. tonsurans over other species as already reported. Since T. tonsurans has not been reported in Africa, the infection of patients of West-African descent probably took place in the Paris area by exchanges with Caribbean patients. This increase of TC due to T. tonsurans was observed in the context of griseofulvin being the only licensed paediatric treatment for TC in France, which should deserve reappraisal because terbinafine may be more efficacious.

Investigating Clinical Issues by Genotyping of Medically Important Fungi: Why and How?

Genotyping studies of medically important fungi have addressed elucidation of outbreaks, nosocomial transmissions, infection routes, and genotype-phenotype correlations, of which secondary resistance has been most intensively investigated. Two methods have emerged because of their high discriminatory power and reproducibility: multilocus sequence typing (MLST) and microsatellite length polymorphism (MLP) using short tandem repeat (STR) markers. MLST relies on single-nucleotide polymorphisms within the coding regions of housekeeping genes. STR polymorphisms are based on the number of repeats of short DNA fragments, mostly outside coding regions, and thus are expected to be more polymorphic and more rapidly evolving than MLST markers. There is no consensus on a universal typing system. Either one or both of these approaches are now available for Candida spp., Aspergillus spp., Fusarium spp., Scedosporium spp., Cryptococcus neoformans, Pneumocystis jirovecii, and endemic mycoses. The choice of the method and the number of loci to be tested depend on the clinical question being addressed. Next-generation sequencing is becoming the most appropriate method for fungi with no MLP or MLST typing available. Whatever the molecular tool used, collection of clinical data (e.g., time of hospitalization and sharing of similar rooms) is mandatory for investigating outbreaks and nosocomial transmission.

[Trichophyton tonsurans associated with non-albicans Candida species in hands onychomycosis about a Moroccan case]

INTRODUCTION

Trichophyton tonsurans is an anthropophilic dermatophyte, frequent in the USA and in Asia where it is responsible for causing tinea capitis. At present, we attend an emergence of this species in certain regions where it was not or little met. Here, we report a case of onychomycosis of the hand due to T. tonsurans associated with non-albicans Candida species at an adult woman.

OBSERVATION

The patient is a 62-year-old woman, with hypertension and diabetes. She reports the rather frequent use of chemical cleaners for the housework. She presented one year previously a distal onycholysis of the last four fingers of the left hand. The clinical examination objectified a presence of intertrigo in the second interdigital space. The mycological examination showed at the direct examination mycelial elements and the culture allowed the isolation of T. tonsurans associated with non-albicans Candida species.

DISCUSSION-CONCLUSION

Our observation highlights especially the identification of a species, which has been described only once in Morocco about a case with onychomycosis of the feet. A possible emergence of this species in our country is not far from being possible.

Genetic Predictors of Susceptibility to Dermatophytoses

Countless observational studies conducted over the last century reveal that dermatophytes infect humans of every age, race, gender, and socioeconomic status with strikingly high rates. The curious disparity in dermatophyte infection patterns observed within and between populations has led countless investigators to explore whether genetics underlie a susceptibility to, or confer protection against, dermatophyte infections. This paper examines the data that offer a link between genetics and dermatophytoses and discusses the underlying mechanisms that support these observations.

Management of a Trichophyton tonsurans outbreak in a day-care center

Trichophyton tonsurans is the leading cause of tinea capitis in the United Kingdom (UK) as well as causing tinea corporis. This organism has been linked to several outbreaks in the UK and abroad, and such outbreaks may be prolonged since T. tonsurans can be difficult to control. There remains an incomplete consensus in the literature on the optimal management of such outbreaks of this infection. Following notification that a child with T. tonsurans was identified at a day-care center in the UK, initial investigations identified nine cases of fungal infection involving children and staff over the previous 7 months. We report on the management of an outbreak of T. tonsurans tinea capitis and tinea corporis among children and staff in a day-care center. An outbreak control team with representatives from dermatology, microbiology, day-care center management, and the Health Protection Agency initiated case ascertainment by scalp inspection and brushing of all children and staff at the nursery. Two complete rounds of screening were required before the outbreak was declared over. Infection control measures included antifungal shampoo use, exclusion of identified cases for a short period, removal of shared items from the center, and enhanced decontamination of fomites. The outbreak, which lasted longer than 12 months, involved 12 children and 7 staff members. Of these, 12 cases were confirmed by positive fungal culture. T. tonsurans is difficult to manage, especially in childcare settings, but case ascertainment, appropriate treatment with oral agents, and sustained infection control measures can be effective in controlling such outbreaks.

Griseofulvin Only Modestly Diminishes Persistence of Trichophyton tonsurans on the Scalp of Carriers

OBJECTIVES

Using genetic strain typing, we previously identified a high rate of T. tonsurans carriage among preschool-aged children attending an urban daycare center. No treatment was provided as part of the observational study; however, children when symptomatic were treated in accordance with daycare policies. This retrospective investigation examines antifungal drug therapy received during the previous investigation and characterizes the impact of treatment on persistence of the fungus on the scalp.

METHODS

Children in whom serial typeable isolates of T. tonsurans were recovered were eligible for evaluation. Clinic charts were reviewed and dispensing records obtained from the primary pharmacies serving the daycare. Infection patterns were examined before and after treatment.

RESULTS

We identified 72 dispensing records for 53 children, all of whom received griseofulvin. Nine children could not be evaluated because treatment was coincident with their last study visit. Thus, 63 treatment events in 44 children with 331 discrete infection events remained. After a single course of griseofulvin, 22.7% of children became culture negative, 6.8% acquired another strain of T. tonsurans and, 70.5% remained persistently positive with the same strain carried prior to treatment. Among those receiving a second course of therapy, 54% remained positive and the cumulative percent of children that became culture negative increased to 36.4%. If children subsequently acquiring a different strain are considered together with those that became culture negative, cumulative strain clearance was observed in 43% of children. Neither the griseofulvin dose nor the duration of time over which children were infected prior to treatment differed between those that remained positive and those that became negative.

CONCLUSIONS

Griseofulvin eradicates dermatophyte scalp carriage in less than one-half of preschool-aged children receiving between one and four 4-week courses of the drug.

A large outbreak of Trichophyton tonsurans among health care workers in a pediatric hospital

BACKGROUND

Although Trichophyton tonsurans remains a major cause of dermataophytoses in US children, nosocomial spread may go unrecognized in health care settings. We describe a staff outbreak of T tonsurans infection among health care workers in a freestanding pediatric hospital.

METHODS

Epidemiologic evaluation (retrospective and prospective) was performed in the health care providers and ancillary staff assigned to a 27-bed inpatient medical unit in which the suspected outbreak occurred.

RESULTS

Twenty-one individuals, including staff, a hospital volunteer, and a patient, developed tinea corporis during a 5-month period. All infections coincided with multiple admissions of a 2-year-old suspected index patient who demonstrated persistent infections of the scalp and arm. Fungal isolates obtained from the index patient and affected staff (when available) were subjected to multilocus strain typing, which revealed an identical genetic match between the index case and infected hospital personnel.

CONCLUSION

T tonsurans can spread widely among staff members caring for children with recalcitrant dermatophyte infections. Recognition that workplace transmission may be the etiology of a succession of infections occurring in a single inpatient unit is necessary to limit the number of infected individuals.

The emergence of Trichophyton tonsurans in Port-au-Prince, Haiti

The occurrence of the anthropophilic dermatophyte Trichophyton tonsurans as a frequent causative agent of tinea capitis in several developed countries has been associated with a global rise in its isolation during recent years. While T. tonsurans was never found in Haiti before 1988, a sharp increase in the number of isolates of this species from scalp lesions began to be observed in 2005 in Port-au-Prince, Haiti. A prospective study was conducted in Port-au-Prince from May to November 2006 of 64 children presenting with tinea capitis at the dermatological outpatient clinic of the university hospital. Forty-five (70%) were male and 19 female (30%), with an average age at presentation of 6.1 years (age range 1-16 years). Direct microscopic examination of scalp hair using 10% potassium hydroxide was positive in 93.8% and culture confirmation was established in 55 cases (85.9%). Five species of dermatophytes were identified, with the anthropophilic dermatophyte T. tonsurans, accounting for the majority or 35 (63.6%) of all cases of tinea capitis. Other dermatophyte species identified included T. mentagrophytes (14.5%), Microsporum audouinii (12.7%), T. rubrum (7.3%) and in one case, the geophilic M. gypseum (1.8%). In two cases caused by T. tonsurans skin involvement on other areas of the body was recorded. The most frequent pathogen in tinea capitis is now T. tonsurans in Port-au-Prince. We speculate that the recent emergence of T. tonsurans in Haiti is linked to the dramatically increasing mobility of Haitian Diaspora.

Epidemiology of tinea capitis in Europe: current state and changing patterns

Tinea capitis (scalp ringworm) is the most common dermatophyte infection of the scalp affecting mainly children and rarely adults. The epidemiology of tinea capitis varies within different geographical areas throughout the world. It may occur sporadically or epidemically and an increase in its incidence has been noted over the last few decades. The aim of the study is to obtain a general overview of the current state and changing pattern of tinea capitis in Europe. According to the literature, there has been a significant increase in the incidence of tinea capitis and a change in the pattern of infectious agents in particular. Microsporum canis, a zoophilic dermatophyte, is still the most common reported causative agent of tinea capitis in Europe. The countries reporting the highest incidence of M. canis infections are mainly in the Mediterranean but also bordering countries like Austria, Hungary, Germany and Poland. Besides the increase in Microsporum-induced tinea capitis, there is a shift towards anthrophilic tinea capitis mainly in urban areas in Europe. The largest overall increase with anthropophilic dermatophytes has been noted with Trichophyton tonsurans mainly in the UK and with Trichophyton soudanense and Microsporum audouinii in France. The occurrence of anthropophilic infections seems to be geographically restricted and is possibly linked to the immigration from African countries. Children (aged 3-7 years with no predilection of gender) remain the most commonly affected, but recently an increase of tinea capitis has been observed in adults and in the elderly. The results of the study clearly demonstrate the importance of diagnosing and proper treatment of mycotic scalp infection in the Europe. If not diagnosed and treated properly, its prevalence might reach epidemic proportions in the near future. Therefore, an increased level of surveillance (screening in schools), and a highly effective interdisciplinary cooperation among general practitioners, mycologists, veterinarians and dermatologists are strongly recommended.

Tracking Trichophyton tonsurans through a large urban child care center: defining infection prevalence and transmission patterns by molecular strain typing

OBJECTIVES

Trichophyton tonsurans is the single most common cause of pediatric dermatophytoses in North America and is observed with increasing frequency in other countries. This investigation was designed to gain insight into the natural course of T. tonsurans infection.

PATIENTS AND METHODS

This 2-year prospective, longitudinal study evaluated all preschool-aged children attending a single child care center. Scalp cultures were collected monthly from each child in attendance, and the presence of disease symptoms recorded at each visit. Dermatophyte genotype was assigned based on the combination of stable sequence variations (2 length variants, 8 single-nucleotide polymorphisms, a 10-base pair insertion, a 14-base pair deletion) present in 2 gene loci.

RESULTS

A total of 3541 scalp cultures were collected from 446 children during 24 months. Twenty-two percent to 51% of scalp cultures per month were positive, contributing 1390 fungal cultures of which 1048 were typeable. Among children with multiple typeable isolates, 51% exclusively carried the same strain, 37% demonstrated a single predominant strain with secondary strains transiently acquired, and 12% harbored a different strain of T. tonsurans with each typeable culture. The probability that the same strain persisted in subsequent months was 0.898 and unlikely to have arisen by chance. Rates of symptomatic disease were significantly different between exclusive, predominant, and transient carriers of T. tonsurans.

CONCLUSIONS

In contrast to dermatophyte infections in older individuals, where symptomatic disease seems to be a consequence of pathogen acquisition and carriers can be traced to an index case, in this preschool-aged population infection was endemic, and symptomatic disease seemed to represent activation of a single strain that persisted on the scalp.

Épidémiologie des teignes du cuir chevelu

OBJECTIVE

Describe the epidemiology of Tinea capitis in three hospitals in the Val de Marne (suburban district southeast of Paris) and evaluate the usefulness of screening the families of index cases.

METHODS

The study included 3 hospitals: Henri Mondor Hospital, Creteil Intermunicipal Hospital Center and Bicêtre Hospital. Index patients had a positive culture for dermatophytes during visits to the mycology-dermatology or pediatric clinics from January 1998 through December 2002. The diagnostic procedure was identical in all centers. In two centers, scalp samples were taken routinely from family members, even in the absence of clinical lesions. Species were identified according to the phenotypic features of the cultures. We recorded the age, sex, and geographic origin of each patient, when available.

RESULTS

Samples were obtained from 487 outpatients (including family members): 383 were positive (356 children under 16 years, 27 adults). Of the children with positive cultures, 214 were boys (60%); of the adults, 18 (66%) were women. Distribution of geographic origin was: sub-Saharan Africa (71%), Europe (10%), Caribbean (5%) and North Africa (4,7%). Species identification confirmed the predominance of anthropophilic species, with 46% of the isolates Trichophyton soudanense and 33% Microsporum langeronii. T. violaceum was reported in 5.5% of cases and T. tonsurans in 2.8%. M. canis (9%), found in 34 Europeans, was the main zoophilic species. Family screening accounted for 263 of the 487 outpatients. Of 242 children from 86 families, 153 (63%) had positive cultures. Of the 21 parents, 5 had a positive culture. Globally, the family screening identified 158 cases in 263 tests (60%).

CONCLUSION

Tinea capitis in the Val de Marne is mainly due to anthropophilic species and involves children of African origin. The frequency of family contamination indicates that routine screening of family members of infected children is valuable.

[Outbreak of cutaneous dermatophytosis in the Judo French Programme in Orleans: September 2004-June 2005]

BACKGROUND

High contact sports regularly allow transmission of infectious agents, including fungi such as dermatophytes. The occurrence of dermatophytosis outbreaks among wrestlers has been extensively described since the 90s. The emergence of such outbreaks among judokas was described for the first time in December 2004. We report here an outbreak which occurred in a high level judo team and is, to our knowledge, the largest ever published.

PATIENTS AND METHODS

From October 2004 to June 2005, every judokas of the Pôle France Orléans who were suspect of dermatophytosis were addressed to one single dermatologist. Lesions were sampled for fungal culture and their anatomical cartography was extensively raised. Two protocols of treatment were defined.

RESULTS

97 medical appointments occurred over the period, leading to 74 clinically-defined episodes of dermatophytosis, distributed as 51 primo-contaminations and 23 re-contaminations (new episode in an individual who was considered cured). The distribution of the lesions on the body was: forearms > anterior trunk > neck and face > scalp. Among the 74 episodes, 53 could grow Trichophyton tonsurans. Infected athletes received oral and topical antifungal treatments. No adverse effects were noticed.

DISCUSSION

This series among judokas is the largest ever published. It allowed the description of the specific clinical and anatomical presentation of tinea corporis gladiatorum, emphasising that contamination takes place through direct skin to skin contacts during practice. T. tonsurans is regularly the responsible fungus in recently published series. Caring for such an outbreak raises specific problems because of the numerous structures involved and of the nature of these structures and of the sportive goals they aim at.

CONCLUSION

This outbreak is probably part of a wider one diffusing among high level judo teams. Stopping it requires the cooperation of several distinct actors, among which sports federations as well as sports-related physicians and dermatologists should play a major role.