[Causative agents of superficial mycoses isolated in Dakar, Senegal: Retrospective study from 2011 to 2015]

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.

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.

The Changing Face of Epidemiology of Dermatophytoses in Chinese Mainland: A 30 years Nationwide Retrospective Study from 1991 to 2020

BACKGROUND

Dermatophytoses are the most common infectious skin disease. Its epidemiology varies in different countries and regions, and its prevalence in China is still unknown.

OBJECTIVES

We aimed to reveal the epidemiological features of dermatophytoses in Chinese mainland in the past thirty years.

METHODS

From 1991 to 2020, a 30-year retrospective epidemiological study was carried out. All published literatures containing dermatophytoses and dermatophytes were collected and analyzed.

RESULTS

A total of more than 180,000 cases in 124 articles from more than 100 hospitals were included and analyzed. Among dermatophytoses, tinea cruris (24.92%) was the predominant clinical type, followed by tinea pedis (22.97%) and tinea corporis (18.12%). In recent 10 years, tinea pedis (25.40%) was more common than tinea cruris (22.39%) and became the most common infection. Among dermatophytes, T. rubrum (69.48%) has always been the most common isolates, followed by T. mentagrophytes (16.45%) and M. canis (8.09%). Other species were found below 3%. In superficial mycoses, dermatophytes accounted for 75.52%, higher than that of yeasts/yeast-like (21.83%) and molds (2.65%). The prevalence of tinea capitis was lower in economically developed eastern region than that in central and western regions. Tinea cruris was more common in warm zones than cold zones.

CONCLUSIONS

The top three dermatophytoses are tinea cruris, tinea pedis and tinea corporis, while the top three dermatophytes are T. rubrum, T. mentagrophytes and M. canis. The distribution of dermatophytoses may be influenced by socioeconomic status and geographical-meteorological conditions.

Evaluation of the Multiplex Real-Time PCR DermaGenius® Assay for the Detection of Dermatophytes in Hair Samples from Senegal

For the successful treatment of dermatophytoses, especially tinea capitis, there is a need for accurate and rapid diagnostic methods. A lot of recent literature has focused on the detection of dermatophytes directly on sample material such as nails, hair and skin scrapings. Molecular tools offer the ability to rapidly diagnose dermatophytosis within 48 h. This study aimed to compare the results of a commercial real-time PCR (real-time PCR) assay DermaGenius^®(DG) 2.0 complete multiplex kit with those of conventional diagnostic methods (direct microscopy and culture). A total of 129 hair samples were collected in Dakar (Senegal) from patients suspected of dermatophytosis. DG was applied for the molecular detection of Candida albicans, Trichophyton rubrum/soudanense, T. interdigitale, T. tonsurans, T. mentagrophytes, T. violaceum, Microsporum canis, M. audouinii, Epidermophyton floccosum, T. benhamiae and T. verrucosum. Dermatophytes species and C. albicans were differentiated by melting curve analysis. The sensitivity and specificity of the PCR assay were 89.3% and 75.3%, respectively. DG PCR was significantly more sensitive than culture (p < 0.001). DG PCR is fast and robust to contamination. In this paper, the main questions discussed were the replacement of culture by a broad-spectrum fungal real-time PCR and the implementation of DG PCR into a routine laboratory in Senegal.

A Comparative Study on Phenotypic versus ITS-Based Molecular Identification of Dermatophytes Isolated in Dakar, Senegal

Classically, dermatophytes are identified by phenotypic methods even if these methods, sometimes, remain difficult or uncertain. On the other hand, nucleotide sequence analysis of internal transcribed spacers (ITS) of rDNA has proved to be a useful method for identification of dermatophytes. The objective of this study was to compare the phenotypic method with DNA sequencing of the ITS regions for identification of dermatophyte species isolated in Dakar, Senegal. A collection of thirty-two strains of dermatophytes were isolated from patients suffering from dermatophytosis. Mycological identification revealed Trichophyton soudanense (n = 13), T. interdigitale (n = 10), Microsporum audouinii (n = 5), and one strain for each of the following species: T. rubrum, T. mentagrophytes, and M. canis and one unidentified strain. For comparison, ITS-based PCR and DNA sequencing were applied for identification of the isolated dermatophytes. ITS sequences showed, in BLAST search analysis, 99-100% of similarity. Identification of dermatophyte isolates by conventional methods was confirmed by DNA sequencing of the ITS regions in 84% of cases. Discrepancies concern mostly T. rubrum misidentified as T. interdigitale. PCR sequencing provided an excellent tool for identifying dermatophyte strains that do not present typical morphological characteristics. It was also able to give correct identification of an atypical strain of M. audouinii responsible of mycetoma of the scalp.

Tinea manuum: A report of 18 cases observed in the metropolitan area of Milan and review of the literature

OBJECTIVE

Tinea manuum is considered in Italy as an uncommon infection, although no recent epidemiological data are available.

METHODS

In the period 2000-2018, we observed in the metropolitan area of Milan 18 patients with mycologically tinea manuum.

RESULTS

The infection was monolateral in all patients and characterised by erythema and scaling; in two patients, each vesicles and pustules were present. Two patients had also onychomycosis of one fingernail. No cases of simultaneous tinea pedis were observed. As far as the job of these patients is concerned, seven of them were masseurs, three barbers, two cattlemen, two masons, one car mechanic, one florist, one maid and one veterinarian. Trichophyton rubrum was isolated in 6 patients, Microsporum canis in 4, Trichophyton gypseum in 3, Trichophyton verrucosum in 3 and Trichophyton violaceum in 2 patients.

CONCLUSION

Masseurs were the most affected. Trichophyton rubrum and Microsporum canis were the most frequent isolated dermatophytes.

Global and Multi-National Prevalence of Fungal Diseases-Estimate Precision

Fungal diseases kill more than 1.5 million and affect over a billion people. However, they are still a neglected topic by public health authorities even though most deaths from fungal diseases are avoidable. Serious fungal infections occur as a consequence of other health problems including asthma, AIDS, cancer, organ transplantation and corticosteroid therapies. Early accurate diagnosis allows prompt antifungal therapy; however this is often delayed or unavailable leading to death, serious chronic illness or blindness. Recent global estimates have found 3,000,000 cases of chronic pulmonary aspergillosis, ~223,100 cases of cryptococcal meningitis complicating HIV/AIDS, ~700,000 cases of invasive candidiasis, ~500,000 cases of Pneumocystis jirovecii pneumonia, ~250,000 cases of invasive aspergillosis, ~100,000 cases of disseminated histoplasmosis, over 10,000,000 cases of fungal asthma and ~1,000,000 cases of fungal keratitis occur annually. Since 2013, the Leading International Fungal Education (LIFE) portal has facilitated the estimation of the burden of serious fungal infections country by country for over 5.7 billion people (>80% of the world's population). These studies have shown differences in the global burden between countries, within regions of the same country and between at risk populations. Here we interrogate the accuracy of these fungal infection burden estimates in the 43 published papers within the LIFE initiative.