Epidemiological and Mycological Aspects of Onychomycosis in Dakar (Senegal)

Synergistic activity between conventional antifungals and chalcone-derived compound against dermatophyte fungi and Candida spp

The scarce antifungal arsenal, changes in the susceptibility profile of fungal agents, and lack of adherence to treatment have contributed to the increase of cases of dermatomycoses. In this context, new antimicrobial substances have gained importance. Chalcones are precursors of the flavonoid family that have multiple biological activities, have high tolerability by humans, and easy synthesis. In this study, we evaluated the in vitro antifungal activity, alone and in combination with conventional antifungal drugs, of the VS02-4'ethyl chalcone-derived compound against dermatophytes and Candida spp. Susceptibility testing was carried out by broth microdilution. Experiments for determination of the target of the compound on the fungal cell, time-kill kinetics, and toxicity tests in Galleria mellonella model were also performed. Combinatory effects were evaluated by the checkerboard method. Results showed high activity of the compound VS02-4'ethyl against dermatophytes (MIC of 7.81-31.25 μg/ml). The compound targeted the cell membrane, and the time-kill test showed the compound continues to exert gradual activity after 5 days on dermatophytes, but no significant activity on Candida. Low toxicity was observed at 250 mg/kg. Excellent results were observed in the combinatory test, where VS02-4'ethyl showed synergistic interactions with itraconazole, fluconazole, terbinafine, and griseofulvin, against all isolates tested. Although further investigation is needed, these results revealed the great potential of chalcone-derived compounds against fungal infections for which treatments are long and laborious.

Epidemiologic, Clinical and Mycological Profile of Onychomycosis in the Hospital Setting in Benin

Introduction: Onychomycosis accounts for 50% of nail disorders and remains one of the most frequent reasons for consultation in dermatology. Several factors favour the development of onychomycosis, such as age, morphological abnormalities of the nails, immunodeficiency and certain underlying pathologies. The aim was to study the epidemiological and diagnostic profile of onychomycosis in patients treated in the dermatology and venerology department of the Benin referral hospital. Patients and Methods: This was a retrospective study conducted from 2003 to 2022, covering patients treated for onychomycosis in the Dermatology-Venerology University Clinic at the National University Hospital Center Hubert Koutoukou Maga (NUHC-HKM) in Cotonou. Results: During the study period, 389 new patients were seen for onychopathy, 301 of whom had a clinical suspicion of onychomycosis. Of these, 128 were confirmed by mycological examination, giving a hospital frequency of onychomycosis of 32.90% compared with onychopathy. The mean age was 44.93 ± 12.50 years; the patients were predominantly female, with a sex ratio (M/F) of 0.41. Aesthetic complaints (76.47%) were the most frequent reason for consultation, and the nail of the hand was the most common lesion location. Melanonychia was the most frequent morphological anomaly, and distolateral subungual onychomycosis was the most frequent clinical form. Yeasts (86.92%) were the most isolated group of fungi, followed, respectively, by moulds (08.44%) and dermatophytes (04.64%). Candida albicans (21.52%) was the most common species. Conclusion: Onychomycosis is relatively uncommon in hospitals in Benin. This is underestimated because most patients with a clinical suspicion of onychomycosis do not undergo a mycological examination before being put on antifungal treatment.

Onychomycosis due to Fusarium species in different continents, literature review on diagnosis and treatment

Fusarium species are an emerging cause of onychomycosis, and the number of cases has dramatically increased in recent decades worldwide. This review presents an overview of the onychomycosis cases caused by Fusarium species and diagnosis and treatment that have been reported in the literature. The most common causative agent of onychomycosis is F. solani species complex, which accounts for 11.68% of the cases of Fusarium onychomycosis, followed by the F. oxysporum species complex (164 out of 1669), which is accounted for 9.83% of the total. F. fujikuroi species complex (42 out of 1669) and F. dimerum species complex (7 out of 1669) are responsible for 2.52% and 0.42 cases, respectively. Fusarium nail infections were reported in patients aged range 1-98, accounting for 5.55% (1669 out of 30082) of all cases. Asia has the highest species diversity of Fusarium onychomycosis (31.51%). South America accounts for 21.09%, and the most common causative agent is F. solani (19.32%), followed by F. oxysporum species complex (15.63%). Europe accounts for 4.90% of cases caused by F. oxysporum, followed by F. solani. Africa accounts for 23.87% of the cases due to the F. solani species complex, followed by F. oxysporum and F. fujikuroi. Distal and lateral subungual onychomycosis was the most common clinical symptom accounting for 58.7% (135 out of 230) of the cases. Data analysis relieved that terbinafine and itraconazole are active treatments for Fusarium onychomycosis. For a definitive diagnosis, combining of direct examination, culture and sequencing of the elongation factor of translation 1α are recommended. Accurate identification of the causative agents of onychomycosis due to Fusarium species and antifungal susceptibility testing is essential in patient management.

Clinical and epidemiological study of onychomycosis among patients of the national institute of hygiene in rabat, Morocco (2016-2020)

Background and Purpose

 Onychomycosis is a common nail infection characterized by the discoloration, thickening, and detachment of nails. This study aimed to provide valuable insights into this pathology by assessing its prevalence, clinical aspects, related comorbidities, and causative agents in patients from a Moroccan population.

Materials and Methods

 This retrospective study was conducted on 1,606 subjects at the Mycology-Parasitology laboratory of the National Institute of Hygiene in Rabat, Morocco, over five years (2016-2020). Nail samples were collected from both fingernails and toenails and processed through microscopic examination and culture. The incubated tubes were kept at a temperature range of 28-30°C for 4-5 weeks.

Results

 Onychomycosis was mycologically confirmed in 1,794 samples (93.24%). It occurred commonly in the 41-60 age group, with a higher incidence among females (74.53%). Diabetes, alongside other chronic diseases, was prevalent among patients with underlying conditions, comprising 131 cases (40.56%). Disto-lateral subungual onychomycosis emerged as the most prevalent clinical presentation, comprising 1,536 cases (79.92%). Fingernails primarily affected by yeasts, notably Candida albicans, accounted for 565 cases (29.80%), while toenails were predominantly impacted by dermatophytes, primarily Trichophyton rubrum (n=1,230, 64.87%). Mixed infections exclusively featured yeasts and dermatophytes, predominantly T. rubrum and C. albicans, which accounted for 79 (4.40%) cases. The study explored the influence of molds, yielding insights into their rarity in onychomycosis.

Conclusion

 These findings hold significant implications for the clinical management and diagnosis of onychomycosis, particularly in patients with underlying chronic conditions. Further epidemiological studies across Morocco are needed for meaningful comparisons.

On the Basis of Sex: Impact and Treatment of Toenail Onychomycosis in Female Patients

Onychomycosis is a fungal infection of the nail unit affecting approximately five percent of the global population and representing 50 percent of all nail dystrophies seen in clinical practice. Patients with onychomycosis can suffer significant pain in addition to physical and psychological distress, which may seriously impair their quality of life (QoL). It is well established that onychomycosis prevalence is impacted by patient characteristics, including age and systemic comorbidities. However, the impact of patient sex on onychomycosis occurrence and treatment is not well characterized. This narrative review of the literature was conducted to address a dearth of published information on epidemiology, QoL, clinical trial participation, and treatment success specifically in female patients with onychomycosis. Additionally, an analysis of real-world treatment of onychomycosis in female patients is reported, including prescription patterns and the impact of toenail polish on topical treatments for onychomycosis. Understanding sex as a clinically relevant variable may inform onychomycosis treatment strategies and improve treatment outcomes.

The First Report of In Vitro Antifungal and Antibiofilm Photodynamic Activity of Tetra-Cationic Porphyrins Containing Pt(II) Complexes against Candida albicans for Onychomycosis Treatment

Onychomycosis is a prevalent nail fungal infection, and Candida albicans is one of the most common microorganisms associated with it. One alternative therapy to the conventional treatment of onychomycosis is antimicrobial photoinactivation. This study aimed to evaluate for the first time the in vitro activity of cationic porphyrins with platinum(II) complexes 4PtTPyP and 3PtTPyP against C. albicans. The minimum inhibitory concentration of porphyrins and reactive oxygen species was evaluated by broth microdilution. The yeast eradication time was evaluated using a time-kill assay, and a checkerboard assay assessed the synergism in combination with commercial treatments. In vitro biofilm formation and destruction were observed using the crystal violet technique. The morphology of the samples was evaluated by atomic force microscopy, and the MTT technique was used to evaluate the cytotoxicity of the studied porphyrins in keratinocyte and fibroblast cell lines. The porphyrin 3PtTPyP showed excellent in vitro antifungal activity against the tested C. albicans strains. After white-light irradiation, 3PtTPyP eradicated fungal growth in 30 and 60 min. The possible mechanism of action was mixed by ROS generation, and the combined treatment with commercial drugs was indifferent. The 3PtTPyP significantly reduced the preformed biofilm in vitro. Lastly, the atomic force microscopy showed cellular damage in the tested samples, and 3PtTPyP did not show cytotoxicity against the tested cell lines. We conclude that 3PtTPyP is an excellent photosensitizer with promising in vitro results against C. albicans strains.

Epidemiology of Onychomycosis in Chinese Mainland: A 30-year Retrospective Study

BACKGROUND

Onychomycosis was a common nail disease caused by dermatophytes, yeasts or molds. The prevalence of onychomycosis varied in different counties and it was necessary to understand the epidemiology in China.

OBJECTIVES

This study was conducted to investigate the epidemiology of onychomycosis in Chinese mainland in the past 30 years.

METHODS

A 30-year systemic review was carried out by searching publications investigating the prevalence of onychomycosis in Chinese mainland from 1991 to 2020.

RESULTS

A total of 90 articles involving more than 40,000 onychomycosis patients were enrolled in this study. The ratio of males to females was 1:1.32. Fingernail onychomycosis was found in 36.12% cases, toenail onychomycosis in 48.31%, and both fingernail and toenail onychomycosis in 15.57%. The most common clinical type of onychomycosis was distal lateral subungual onychomycosis (60.99%), followed by total dystrophic onychomycosis (18.91%), proximal subungual onychomycosis (10.19%) and superficial white onychomycosis (9.92%). Dermatophytes (60.59%) were the most frequently isolated pathogens, followed by yeasts (30.09%), molds (7.91%) and mixed infection (1.41%). The primary pathogens in dermatophytes, yeasts and molds were Trichophyton rubrum (49.93%), Candida albicans (10.99%) and Aspergillus (3.11%), respectively. Additionally, dermatophytes were more commonly affected males than females (63.69% vs. 51.57%), and mostly involved in toenail onychomycosis (75.63%). The infection of yeasts was higher in females than males (40.97% vs. 29.52%), often causing onychomycosis in fingernail than toenail (41.03% vs. 17.08%), and it was more common in warm and humid southern regions than northern area (34.07% vs. 24.41%).

CONCLUSION

The proportion of the causative agents changed over time, dermatophytes, especially T. rubrum had always been the predominant pathogen, followed by yeasts and molds. The distribution of fungal pathogens varied among clinical types, gender, infection sites and geography gender.

Comparison of Fungal Fluorescent Staining and ITS rDNA PCR-based Sequencing with Conventional Methods for Diagnosis of Onychomycosis

Accurate identification of fungal causes for onychomycosis is essential for proper treatment. Presently available laboratory methods show unreliable sensitivity; so there is a requirement for innovative detection techniques. The aim for this work was to assess the efficiencies of fluorescent staining and internal transcribed spacer (ITS) ribosomal DNA (rDNA) polymerase chain reaction (PCR)-based sequencing in comparison to conventional techniques for diagnosis of onychomycosis. Nail specimens obtained from 100 patients with clinically- diagnosed onychomycosis were analyzed. Nail scrapings or clippings were subjected to direct microscopic examination by KOH mount, culture by using Sabouraud’s dextrose agar and histopathological examination with periodic-acid Schiff (PAS). Collected specimens were subsequently examined by fluorescent staining and PCR-based sequencing (30 specimens only) to compare the feasibility, sensitivity and diagnostic accuracy for these two methods. The most frequently isolated fungi were yeasts (39/76: 51.3%), dermatophytes (24/76; 31.6%) and non-dermatophyte molds (NDMs) (13/76; 17.1%). Mixed mycotic infections were recovered from 6% of the collected nail specimens. The positive detection rates were significantly different between KOH examinations (52%), nail plate histology (55%), fungal culture (70%) and fluorescent staining (80%). Considering fungal culture as the gold standard, the most sensitive technique was PCR (100%) followed by fluorescent staining (89%), PAS staining (69%) while the least sensitive technique was KOH mount (53%). Fluorescence staining can be used as a rapid and high-yield technique for identification of fungi in the specimens. PCR-based sequencing was highly sensitive and faster compared to culture. Whenever possible, it enables species identification with higher adequacy.

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 epidemiology and etiology of onychomycosis in 2 laboratory centers affiliated to Tehran university of medical sciences during 2019-2020

Background and Objectives

Onychomycosis is caused by dermatophyte species, non-dermatophyte moulds (NDMs), and accounts for roughly 50% of all nail diseases. As the prevalence of onychomycosis is increasing, new epidemiologic documents may help with treatment and prevention. The present investigation aims to determine the epidemiological profile of onychomycosis in 2 mycology laboratories.

Materials and Methods

A cross-sectional study conducted during eight months (2019-2020) on 169 patients with positive nail mycology tests referred to two mycological laboratory centers affiliated with Tehran University of Medical Science. The nail clippings were examined by direct smear and culture. Also, molecular assays were performed if needed.

Results

10% of nail lesions referred to Razi Hospital (RH), and 30% of nail lesions referred to TUMS mycology laboratory were positive. Middle age (40-60) suffer more from onychomycosis. Aspergillus flavus, Trichophyton mentagrophytes, and Candida albicans were the most common etiologic agents in each of the three main classes of fungi causing onychomycosis. Females were more infected. NDMs were the predominant etiologic agents, and toenails were the most common site of onychomycosis.

Conclusion

The pattern of etiologic agents and clinical signs of onychomycosis differs according to geographical region and age, so repeated epidemiological surveys of onychomycosis seem to be fundamental.

Non-dermatophyte fungi in onychomycosis-Epidemiology and consequences for clinical practice

Onychomycoses are difficult-to-treat fungal infections with a high recurrence rate that relates to the anatomic and pathophysiological conditions in the nail organ and the required extended duration of treatment. Clinical-epidemiological studies demonstrated that non-dermatophyte molds and yeasts are the primary causative agents in 20%-30% of onychomycoses. Mixed infections with dermatophytes are observed as well. Therefore, the causative agents should be determined by fungal culture and the antifungal treatment regimen should reliably cover non-dermatophytes, if appropriate. Systemic-topical combination therapy involving a broad-spectrum, locally applied antifungal may increase the mycological and clinical cure rates compared to monotherapy with systemic drugs.

Onychomycosis in Northwestern Greece Over a 7-Year Period

Onychomycosis is considered as one of the major public health problems with a global distribution associated with geographic, demographic and environmental factors, underlying comorbidities and immunodeficiency disorders. This study was conducted to investigate the etiological agents of onychomycosis, in Northwestern Greece during a 7-year period. The study population included 1095 outpatients with clinically suspected onychomycosis that presented to the University Hospital of Ioannina, NW Greece (2011–2017). Samples were examined for causative fungi, and mycological identification was established using standard mycological methods. Demographic data of each patient, comorbidities, localization of infection and history of previous fungal infection were collected. Onychomycosis was diagnosed in 317 of the 1095 suspected cases (28.9%) and the most frequently isolated pathogens were yeasts (50.8%) followed by dermatophytes (36.9%) and non-dermatophyte molds (NDMs) (12.3%). Dermatophytes were mostly involved in toenail onychomycosis (90.6%) and more commonly affected males than females (57.3% vs. 42.7%), while the predominantly isolated pathogen was Τrichophyton rubrum (74.4%) followed by Τrichophyton interdigitale (21.4%). Candida albicans was the most prevalent isolated yeast (82%), whereas among the cases with onychomycosis due to NDMs, Aspergillus spp. were isolated as the principal species (59%). Continuous monitoring should be performed in order to identify possible trends and shifts in species isolation rates and to evaluate the impact of onychomycosis among the general population and high-risk groups.