Emergence of African species of dermatophytes in tinea capitis: A 17-year experience in a Montreal pediatric hospital

Exploring treatment and antifungal resistance in an outbreak of tinea caused by Microsporum audouinii

BACKGROUND

Microsporum audouinii has resurged recently. Infections with the dermatophyte are difficult to treat, which raises the question if we treat M. audouinii infections with the most effective antifungal (AF) agent.

OBJECTIVES

The aims of this study was to investigate an outbreak of tinea capitis (TC) in Denmark, address the challenges in outbreak management and to conduct two reviews regarding previous outbreaks and minimal inhibitory concentration (MIC).

METHODS

We used Wood's light, culture, direct microscopy, and PCR for screening and antifungal susceptibility testing (AFST) for treatment optimization. We performed two reviews to explore M. audouinii outbreaks and MIC values using broth microdilution method.

RESULTS

Of 73 screened individuals, 10 had confirmed M. audouinii infections. Clinical resistance to griseofulvin was observed in 4 (66%) cases. While previous outbreaks showed high griseofulvin efficacy, our study favoured terbinafine, fluconazole and itraconazole in our hard-to-treat cases. AFST guided the choice of AF. Through the literature search, we identified five M. audouinii outbreaks, where differences in management included the use of Wood's light and prophylactic topical AF therapy. Terbinafine MIC values from the literature ranged from 0.002 to 0.125 mg/L.

CONCLUSION

Use of Wood's light and preventive measurements were important for limiting infection. The literature lacked MIC data for griseofulvin against M. audouinii, but indicated sensitivity for terbinafine. The clinical efficacy for M. audouinii treatment was contradictory favouring both terbinafine and griseofulvin. AFST could have a key role in the treatment of difficult cases, but lack of standardisation of AFST and MIC breakpoints limits its usefulness.

Tinea Capitis at Ibn Sina Hospital in Rabat, Morocco: Epidemiological and Etiological Study Over 25 Years (From 1997 to 2021)

Introduction/Objective In Morocco, tinea capitis is a common reason for consultation, especially in children. Our study aimed to determine the epidemiology of tinea capitis in the Central Laboratory of Parasitology and Mycology at the Ibn Sina University Hospital Center (UHC) in Rabat. Materials and methods This is a retrospective study conducted over 25 years (from 1997 to 2021). It included 247 patients with lesions suggestive of tinea capitis, who underwent a mycological examination. Results Among 594 requests for the diagnosis of tinea capitis, 247 cases were positive. A clear predominance of children (86.23%; n=213) as compared to adults (13.77%; n=34) was observed. The sex ratio (M/F) was 1.77. Hair parasitism was mainly dominated by the pure endothrix type 54.47% (n=122). The two most frequently isolated species were Trichophyton violaceum (51.24%; n=125) and Microsporum canis (36.06%; n=88). In children, these two species represented 47.42% (n=101) and 41.31% (n=88), respectively. In adults, Trichophyton violaceum was the predominant species, accounting for 77.42% (n=24); in females, it was 76.41% (n=68); and Microsporum canis was predominant in males (50.32%; n=78). Conclusion The epidemiology of this condition is in a constant state of flux, influenced by various lifestyle factors. Our research unveiled a notable upward trend in zoophilic species over the 25-year study period, while conversely, anthropophilic species demonstrated a discernible decline.

Epidemiology and Clinical Findings of Tinea Capitis: A 23-Year Retrospective, Single-Center Study in Guangzhou, China

BACKGROUND

Tinea capitis (TC) is one of the most common public health concerns due to its high incidence in preadolescent children. The epidemiological and clinical characteristics of TC vary depending on geographical regions and have changed over the past decades.

OBJECTIVES

This study aimed to identify epidemiological changes in recent decades, including the prevalence and clinical and mycological characteristics of TC in southern China.

METHODS

We conducted a retrospective study at the Department of Dermatology of Sun Yat-sen Memorial Hospital, Sun Yat-sen University from June 1997 to August 2020.

RESULTS

We retrospectively evaluated 401 TC patients. Of these, 157 patients (39.2%) were preschool children aged 3-7 years and the majority were males. However, the prevalence in children under 3 years old is on the rise (from 19.67% during 1997-2010 to 32.49% during 2011-2020). Grey patches were the most common clinical pattern and mostly occurred in children (71.3%), while the proportion of grey patches and black dots was almost the same in adults. Although Microsporum canis (76%) was the most common causative organism, the number of the T. mentagrophytes complex, as a zoophilic fungus, has increased more than that of the anthropophilic fungi T. violaceum in the recent decade. There was a significant difference in the portion of sex among different age groups, and the gender difference was more notable in the adult group, which showed that the TC prevalence in females was 9 times that in males. In males, M. canis and the T. mentagrophytes complex were the two most common causative fungi, while M. canis and T. violaceum were the two most common causative fungi in females. Additionally, approximately 61.7% of black dot TCs occurred in females. For treatment, oral antifungal therapeutics were widely used in most patients with different treatment durations, although without a significant difference in efficacy (P = 0.106).

CONCLUSIONS

In the last decade, the prevalence of TC in children under 3 years old increased, and boys dramatically outnumbered girls. In adults, the TC prevalence in females is nine times that in males, and most TCs occurring in females are presented as black dots. Moreover, the zoophilic T. mentagrophytes complex has replaced T. violaceum and is now the second most prevalent organism, followed by M. canis of TC.

Global Demographic Characteristics and Pathogen Spectrum of Tinea Capitis

Tinea capitis is an important superficial fungal infection with a global distribution. It mainly affects prepubertal children and is more common in males. Anthropophilic and zoophilic dermatophytes are responsible for most infections. The pathogen spectrum of tinea capitis varies across different regions and changes over time, and is influenced by multiple factors, such as economic development, changes in lifestyle, immigration and animal distribution. This review aimed to clarify the demographic and etiological characteristics of tinea capitis worldwide and determine the common trends of causative pathogens. By mainly analyzing the literature published from 2015 to 2022, we found that the incidence and demographic characteristics of tinea capitis remained generally stable. Zoophilic Microsporum canis, anthropophilic Trichophyton violaceum and Trichophyton tonsurans were the predominant pathogens. The pathogen spectra in different countries changed in different directions. In some countries, the main pathogen shifted to an anthropophilic dermatophyte, such as T. tonsurans, Microsporum audouinii or T. violaceum; in contrast, it shifted to a zoophilic agent, such as M. canis, in some other countries. Dermatologists are advised to continue monitoring the pathogen spectrum and implement preventive measures according to the reported changes.

Changing Epidemiology of Tinea Capitis in Athens, Greece: The Impact of Immigration and Review of Literature

Mass population movements have altered the epidemiology of tinea capitis (TC) in countries receiving refugees. Periodic monitoring of the local pathogen profiles may serve as a basis for both the selection of appropriate empirical antifungal therapy and the implementation of preventive actions. Therefore, we investigated the impact of an unprecedented immigration wave occurring in Greece since 2015 on the epidemiological trends of TC. All microbiologically confirmed TC cases diagnosed during the period 2012-2019 in a referral academic hospital for dermatological disorders in Athens, Greece, were retrospectively reviewed. A total of 583 patients were recorded, where 348 (60%) were male, 547 (94%) were children and 160 (27%) were immigrants from Balkan, Middle Eastern, Asian as well as African countries. The overall annual incidence of TC was 0.49, with a significant increase over the years (p = 0.007). M. canis was the predominant causative agent (74%), followed by T. violaceum (12%), T. tonsurans (7%) and other rare dermatophyte species (7%). M. canis prevalence decreased from 2014 to 2019 (84% to 67%, p = 0.021) in parallel with a three-fold increase in T. violaceum plus T. tonsurans rates (10% to 32%, p = 0.002). An increasing incidence of TC with a shift towards anthropophilic Trichophyton spp. in Greece could be linked to the immigration flows from different socioeconomic backgrounds.

Pediatric Tinea Capitis: A Retrospective Cohort Study from 2010 to 2021

Pediatric tinea capitis displays a wide range of prevalence, with significant variability among populations. We retrospectively extracted the medical records of 456 pediatric patients diagnosed with tinea capitis during the years 2010–2021, from the dermatology outpatient clinics in two tertiary medical centers. Three species were isolated in 90% of patients: T. tonsurans, M. canis, and T. violaceum. While T. tonsurans presented a six-fold increase in incidence during the years 2019–2021, M. canis maintained stable incidence rates. Furthermore, terbinafine was the most efficient antifungal agent against T. tonsurans, achieving complete clinical clearance in 95% of patients, as compared to fluconazole (68%) and griseofulvin (38%) (p < 0.001). The mycological cure was recorded in 61/90 (68%) of patients with available data, at an average of 10 weeks. For patients with M. canis, griseofulvin and fluconazole were equally efficient (73% and 66%, respectively) (p = 0.44). Kerion was described in 36% and 14% of patients with T. tonsurans and M. canis, respectively, (p < 0.001). In conclusion, since 2019, there has been a significant increase in the prevalence of T. tonsurans, establishing this pathogen as the most common cause for tinea capitis in our population. Our data suggest that terbinafine is effective and presents high cure rates for tinea capitis in the pediatric population.

Epidemiology of dermatomycoses and onychomycoses in Ireland (2001 to 2020): A single-institution review

Background

Fungal skin infections are recognised as one of the most common health disorders globally, and dermatophyte infections of the skin, hair and nails are the most common fungal infections. Dermatophytes can be classified as anthropophilic, zoophilic or geophilic species based on their primary habitat association, and this classification makes epidemiological analysis useful for the prevention and control of these infections. The Irish contribution to the epidemiology of these infections has been scant, with just two papers (both reporting paediatric tinea capitis only) published in the last 20 years, and none in the last seven.

Objectives

To perform a comprehensive retrospective epidemiological analysis of all dermatological mycology tests performed in University Hospital Limerick over a 20‐year period.

Methods

All mycology laboratory test results were extracted from the Laboratory Information Management System (LIMS, iLab, DXC Technologies) from 2001 to 2020 inclusive for analysis. Specimen types were categorised according to the site of sampling. The data were analysed using Microsoft Excel.

Results

About 12,951 specimens of skin, hair and nails were studied. Median patient age was 42 years (IQR 26–57) with a slight female preponderance (57.2%). Two thirds of samples (67%, n = 8633) were nail, 32% were skin scrapings (n = 4118) and 200 hair samples (1.5%) were received. Zoophilic dermatophytes were more commonly present in females (38% F, 23% M, proportion of dermatophytes) and in those under 10 years of age or from 45 to 70 years (36% and 34% zoophiles, respectively, proportion of dermatophytes), although anthropophiles predominated every age and gender category. Anthropophiles had their highest prevalence in the 10–20 years age category (80% anthropophiles, proportion of dermatophytes), and yeast infections were more prevalent in older patients (29% of >60 year olds vs. 17% of <60 year olds, proportion of all fungal positives). Trichophyton rubrum was the most prevalent pathogen detected, accounting for 53% of all dermatophytes detected, 61% of those detected from nail samples and 34% from skin and hair samples. Trichophyton tonsurans was the most prevalent dermatophyte in tinea capitis, accounting for 37% of dermatophytes detected. Both of these organisms are anthropophilic, and this group showed consistently increased prevalence in proportion to all fungal isolates. The proportion of this dermatophyte class (anthropophiles) increased among both nail samples and skin/hair samples during the study period, from 55% of samples in the first 5 years of the study (2001–2005) to 88% (proportion of dermatophytes) in the final 5 years. Conversely, yeast detection decreased.

Conclusions

This study provides a detailed overview of the epidemiology of the fungal cultures of skin, nail and hair samples in the Mid‐West of Ireland over a 20‐year period. Monitoring this changing landscape is important in identifying likely sources of infections, to identifying potential outbreaks, and may help guide empiric treatment. To the best of our knowledge, this study provides the first detailed analysis from Ireland of fungal detections from skin, hair and nail samples, and is the first epidemiological fungal report of any kind in over 7 years.

Clinical clues and trends in epidemiology and pathogens in paediatric tinea capitis: a retrospective cohort study

BACKGROUND

Tinea capitis is the most common dermatophyte infection in children. Pathogens differ between populations. During the past few decades pathogen shifts have been reported in many countries around the world. This study aimed to characterize the pathogens involved in tinea capitis in a large tertiary paediatric medical centre in Israel.

METHODS

The electronic medical records of the dermatology unit were searched for patients diagnosed with tinea capitis from 2010 to 2019, and demographic, clinical and mycological data were retrieved. A stepwise logistic regression was performed to determine the variables most significantly associated with positive cultures.

RESULTS

The prevalence of Trichophyton tonsurans isolates was found to be significantly increased during 2019. In the logistic regression analysis, alopecia was most significantly associated with a positive culture (OR = 8.72, 95% CI 4.29-17.7, P < 0.001) while positive culture was also associated with age (OR = 1.11 per year of age, 95% CI 1.02-1.22, P = 0.01) and Ethiopian ethnicity (OR = 3.67, 95% CI 1.42-9.45, P = 0.01). The presentation of alopecia was significantly related to having a positive culture. This symptom was more prevalent in boys than in girls, and the diagnosis of tinea capitis was delayed by an average of 2 months in girls.

CONCLUSION

The results of this study may herald a pathogen shift in Israel. Physicians should be aware that rates of alopecia are lower in girls and this can result in delayed diagnosis and the development of complications, including chronicity, scarring alopecia and kerion formation.

Determination of dermatophytes isolated from tinea capitis using conventional and ITS-based sequencing methods in Kano, Nigeria

BACKGROUND

Tinea capitis is a dermatophyte infection of the scalp and hair that affects a large number of people worldwide. The disease commonly affects children and manifests with varying degrees of hair loss, scalp inflammation, and psychosocial impact. In Nigeria, the burden of tinea capitis is worrisome affecting over 15,000,000 school-age children. Molecular techniques complement the conventional mycological examinations in laboratory diagnosis of tinea capitis. In this study, we identified dermatophytes species causing tinea capitis in Kano, Nigeria, using ITS-based nucleotide sequencing technique in addition to conventional mycological examination.

METHODS

We collected 112 samples from the scalp of children with clinically diagnosed tinea capitis at the dermatology clinic of Murtala Muhammad Specialist Hospital, Kano, between April and September 2019. The samples were processed and subjected to direct microscopy and mycological culture to isolate dermatophytes species that were identified morphologically and using ITS sequencing.

RESULTS

Out of the 112 patients investigated, the majority (59.8%) were between the ages 6 and 9 years with a mean age of 7.3 ± 1.9 years. Males (79.5%) were predominantly affected. Black dot (46.4%) was the most common clinical type of tinea capitis followed by gray patch (39.3%) and kerion (1.8%). Favus was not observed. Microsporum audouinii (45.7%) was the predominant etiologic agent followed by Trichophyton soudanense (28.6%), T. violaceum (22.9%), and T. tonsurans (2.9%).

CONCLUSION

The prominence of anthropophilic dermatophytes as the main causes of tinea capitis in our localities suggests that public health interventions to promote health education and good hygiene practices would minimize the transmission rate of tinea capitis among children in the study area.

Tinea capitis in children: A single-institution retrospective review from 2011 to 2019

Tinea capitis remains a common public health problem worldwide, especially in developing countries.

OBJECTIVES

To investigate the changes of the predominant dermatophytes of tinea capitis in children in Hangzhou in recent 9 years.

METHODS

The age, gender and pathogen spectrum of 650 children with tinea capitis at the Department of Dermatology, Affiliated Third People's Hospital of Hangzhou, Anhui Medical University from 2011 to 2019 were analysed, and the distribution of pathogens from 1998 to 2000 was compared.

RESULTS

Among the 650 cases, 340 cases (48.2%) were males and 310 cases (51.8%) were females. The main population infected with tinea capitis was children aged 0-10 years (620 cases, 95.4%). From 2011 to 2019, the predominant dermatophyte was changed from Trichophyton violaceum (2011) to Trichophyton mentagrophytes complex (2012-2015) and later to Microsporum canis (2016-2019). In the past 9 years, M. canis (250 cases, 38.5%) was the most common dermatophyte and followed by T mentagrophytes complex (209 cases, 32.2%). The dermatophyte spectrum was statistically different between the years 2011 and 2019 (Chi square: χ²  = 69.75, P < .05), and the differences in anthropophilic and zoophilic pathogens between 1989-2000 and 2011-2019 were statistically significant (χ²  = 24.4, P < .05).

CONCLUSIONS

Research showed that children diagnosed with tinea capitis were mainly 0-10 years old. With age, the percentage of anthropophilic dermatophytes gradually increased, while the percentage of zoophilic dermatophytes decreased. M. canis was the predominant dermatophyte of tinea capitis in children, followed by T. mentagrophytes complex. The dermatophytes have shifted from anthropophilic to zoophilic dermatophytes in the past two decades.

Tinea capitis: A single-institution retrospective review from 2010 to 2015

BACKGROUND/OBJECTIVE

Tinea capitis is a common infection of scalp hair in children. The prevalent etiologic organism has changed significantly over time, which may reflect the complex interaction of environmental factors, genetic predisposition, and movement of populations. We evaluate the prevalence of different infectious organisms causing tinea capitis and describe the clinical characteristics.

METHODS

A retrospective chart review of patients diagnosed with tinea capitis with tissue culture confirmation, who were seen in pediatric dermatology at a tertiary care center from 2010 to 2015. Patient demographics, culture data, and clinical characteristics were evaluated. Inflammatory pattern, characterized by presence of pustules, bogginess, or lymphadenopathy, was noted.

RESULTS

Forty-six patients with culture-positive tinea capitis were identified. In the 18 (42.9%) patients who were infected with either Trichophyton violaceum or Trichophyton soudanenese, all were of African ethnicity. In contrast, Trichophyton tonsurans was identified in a minority of African patients (3.8%), revealing a statistically significant difference between ethnicity and infective species (P-value < 0.001). T tonsurans was significantly more likely than T violaceum to exhibit an inflammatory pattern (68% vs 22%, P value < 0.027).

CONCLUSIONS

While T tonsurans remained the most common cause of tinea capitis, T violaceum and T soudanense have increased in prevalence. As these latter agents are less inflammatory, clinical diagnosis may be delayed. Studying changes in the infectious cause of tinea capitis can help us create a snapshot to better understand the evolution of our population make-up, allowing us to provide crucial quality health care to all.

Determination of antifungal minimum inhibitory concentration and its clinical correlation among treatment failure cases of dermatophytosis

Introduction:

Dermatophytes are most common infectious agents causing superficial mycosis worldwide. A number of topical as well as systemic antifungal drugs are available for treatment of dermatophytosis. Superficial mycosis caused by dermatophytes can be easily treated by topical or oral antifungal drugs, but in the course of time, an increased number of treatment failure cases are appearing. Possible cause for treatment failure could be poor patient compliance, poor drug penetration into affected lesion, and also drug resistance in dermatophytes. The aim of this study is to investigate minimum inhibitory concentration and clinical correlation in treatment failure cases of dermatophytosis.

Methods:

Skin, hair and nail samples were collected from treatment failure cases of dermatophytosis. A total 75 isolates were tested for MIC against four antifungal drugs in the study. Fluconazole, itraconazole, ketoconazole and terbinafine were the antifungal drugs tested using broth microdilution method. MIC₅₀ and MIC₉₀ values were recorded.

Results:

A total of 75 dermatophytic isolates were tested. Dermatophytic isolates in this study were Trichophyton mentagrophytes (n = 31), T. rubrum (n = 13), T. tonsurans (n = 12), T. verrucosum (n = 9), M. gypseum (n = 5), E. floccosum (n = 4) and T. violaceum (n = 1). MIC₉₀ value for fluconazole and terbinafine was significantly higher.

Conclusion:

MIC of 17.33% isolates for fluconazole and 33.33% isolates for terbinafine were lower than cut-off value, which indicates that not all treatment failure cases are due to drug resistance.