Tinea capitis. Emergencia de Microsporum audouinii y Trichophyton tonsurans en la República Dominicana

Fungal Infections in the Caribbean: A Review of the Literature to Date

The most common fungal infections reported from the Caribbean include dermatophytosis, candidiasis, pneumocystis, aspergillosis, histoplasmosis, and cryptococcosis. The Caribbean is hyperendemic for histoplasmosis, with high population exposures. Fungal infections are a significant public health problem in the Caribbean, with rates varying depending on the specific country or region. In Trinidad and Tobago, the fungal burden accounts for 3.3% of the 1.4 million population, while in Jamaica, with a population of 2.9 million, over 57,600 people suffer from fungal infections each year. A study in the Dominican Republic estimated that approximately 221,027 (2%) of over 10 million people have a serious fungal infection. Fungal infections accounts for 21.9% of all skin infections in Haiti. The diagnosis of fungal infections in the Caribbean can be challenging, as access to laboratory testing and specialized medical services is limited in many areas. Access to antifungal medications can also be a challenge in some areas, and antifungal resistance has been reported.

Tinea capitis outbreak and other superficial mycosis in an urban community of Medellín

Introduction. Dermatophytoses are superficial fungal infections of the keratinized epithelium like tinea capitis. The latte mainly affects school-vulnerable populations. Carpinelo is a peripheral neighborhood in Medellín with poor socioeconomic conditions and where a suspected tinea capitis outbreak took place. Objective. To study and characterize, clinically and microbiologically, patients with suspected dermatophytosis in Carpinelo. Material and methods. We carried out a descriptive and longitudinal study with an active case search of tinea capitis in children and their relatives from the Jardín Educativo Buen Comienzo community in Carpinelo. Patients were clinically evaluated, and samples of scales and hair were taken to perform mycological studies with a 10 % potassium hydroxide and culture in Sabouraud and Mycosel agar. We analyzed the data with the statistical program SPSS™. 25 version. Results. Fifty-seven individuals were studied: 47 were children with a mean age of six years and a ratio of 2:1 male to female. Patients with confirmed diagnosis presented the following clinical forms: tinea capitis (78.95%), tinea faciei (15.79%) or tinea corporis (10.52%). Out of the total, 69.76% of the patients had previous treatment with steroids. The direct test was positive in 53.84% of the samples, and 46.15% had positive cultures. The isolated species were: Microsporum canis (77.77%), Trichophyton spp. (11.11%), Trichophyton rubrum (5.55%), and Malassezia spp. (5.55 %). Conclusion. Tinea capitis was the most common clinical form, and M. canis was the most frequently isolated species. The use of steroids as the first and only option for empiric treatment was worth of notice. The findings of this study point out the importance of microbiological diagnosis in choosing the best treatment for the patients.

Phenotypic and Genotypic Identification of Dermatophytes from Mexico and Central American Countries

Dermatophytes are fungi included in the genera Trichophyton, Microsporum, Epidermophyton, Nannizzia, Paraphyton, Lophophyton, and Arthroderma. Molecular techniques have contributed to faster and more precise identification, allowing significant advances in phylogenetic studies. This work aimed to identify clinical isolates of dermatophytes through phenotypic (macro- and micromorphology and conidia size) and genotypic methods (sequences of ITS regions, genes of β tubulin (BT2), and elongation factor α (Tef-1α)) and determine the phylogenetic relationships between isolates. Ninety-four dermatophyte isolates from Costa Rica, Guatemala, Honduras, Mexico, and the Dominican Republic were studied. The isolates presented macro- and micromorphology and conidia size described for the genera Trichophyton, Microsporum, and Epidermophyton. Genotypic analysis classified the isolates into the genera Trichophyton (63.8%), Nannizzia (25.5%), Arthroderma (9.6%), and Epidermophyton (1.1%). The most frequent species were T. rubrum (26 isolates, 27.6%), T. interdigitale (26 isolates, 27.6%), and N. incurvata (11 isolates, 11.7%), N. gypsea and A. otae (nine isolates, 9.6%), among others. The genotypic methods clarified the taxonomic status of closely related species. For instance, the ITS and BT2 markers of T. rubrum/T. violaceum did not differ but the Tef-1α gene did. On the other hand, the three markers differed in T. equinum/T. tonsurans. Therefore, the ITS, BT2, and Tef-1α genes are useful for typing in phylogenetic analyses of dermatophytes, with Tef-1α being the most informative locus. It should be noted that isolate MM-474 was identified as T. tonsurans when using ITS and Tef-1α, but when using BT2, it was identified as T. rubrum. On the other hand, no significant difference was found when comparing the methods for constructing phylogenies, as the topologies were similar.

Tinea Capitis by Microsporum audouinii: Case Reports and Review of Published Global Literature 2000-2016

Tinea capitis caused by Microsporum audouinii is reported herein from two Brazilian schoolchildren, which are brothers. Arthroconidia were evidenced on direct examination of scalp hair, and a fungus of the genus Microsporum was isolated from cultures of each patient. The isolated fungi were classified as M. audouinii by visualization of species-specific structures, including: pectinate hyphae, chlamydospores, and fusiform macroconidia, sterile growth with characteristic brown pigment in rice grains, and through DNA sequencing of the internal transcriber spacer region. Patients were refractory to ketoconazole, but the two cases had a satisfactory response to oral terbinafine. All M. audouinii infections described in this century were reviewed, and to our knowledge, this is the first literature description of this species from South America. Misidentification of M. audouinii with Microsporum canis can occur in this area, leading to erroneous data about the occurrence of this species.

The Changing Face of Dermatophytic Infections Worldwide

Dermatophytes evolve along with the geography and socioeconomic conditions. Epidermophyton floccosum, Microsporum audouinii and Trichophyton schoenleinii acted as the major pathogens of superficial fungal diseases 100 years ago, but their frequency decreased dramatically since the middle of the twentieth century and they are limited to some less-developed countries nowadays; meanwhile, frequency of Trichophyton rubrum, Trichophyton interdigitale, Trichophyton tonsurans and Microsporum canis increased gradually, and these fungi have become the major species globally. Some other dermatophytes, i.e., Trichophyton violaceum, Trichophyton verrucosum and Microsporum ferrugineum, are mainly endemic in some parts of Africa, Asia and Europe. At present, T. rubrum is the leading pathogen for skin and nail fungal infections, whereas M. canis, T. tonsurans and T. violaceum present as the predominant dermatophytes involved in tinea capitis. Population mobility, changes in human lifestyle and advents of antifungal drugs will continually drive the dermatophyte evolution in the skin microenvironment. Comprehensive observation is needed to better understand this kind of organisms and prospect the trends of their changes in future.

Burden of serious fungal infections in the Dominican Republic

The Dominican Republic (DR) is the second largest Caribbean nation and, with Haiti, the DR accounts for nearly three-quarters of the cases of human immunodeficiency virus (HIV) infection in the Caribbean region and the highest rates of TB in the Americas. The present study estimated the burden of serious fungal infections and some other mycoses in the DR. The data were extracted from the World Health Organization Stop Tuberculosis (WHO STOP TB) program, the Joint United Nations Program on HIV/AIDS (UNAIDS), and searches for relevant literature via MEDLINE, PubMed, MedFacts, and so on. The chronic pulmonary aspergillosis (CPA), allergic bronchopulmonary aspergillosis (ABPA), and severe asthma with fungal sensitization (SAFS) rates were derived from the asthma and TB rates. When no data regarding mycoses were available, we used specific populations at risk and the frequencies of fungal infection in each of these populations to estimate the national prevalence. Among its population of 10,090,000, we estimated that 221,027 (2.2%) have a serious fungal infection, including 158,134 women with recurrent vulvovaginal candidiasis. We estimated high numbers of 25,150 for ABPA and 34,000 for severe asthma fungal sensitization (SAFS) (250 and 529/100,000, respectively). CPA was common, with an estimated 2122 cases, of which 707 followed pulmonary TB. The annual prevalence of CPA was estimated to be 1374 cases. Four cases of histoplasmosis and several cases of chromoblastomycosis have also been reported. Pityriasis versicolor and tinea capitis are frequent in children, and 11% have kerion. Local epidemiological investigations are urgently required to validate or modify these estimates of serious fungal infections in the DR.