Demodex Mite Density Determinations by Standardized Skin Surface Biopsy and Direct Microscopic Examination and Their Relations with Clinical Types and Distribution Patterns

BACKGROUND: Demodicosis is a parasitic skin disease caused by Demodex mites, and the determination of mite density per square centimeter is important to diagnose demodicosis. Standardized skin surface biopsy (SSSB) and direct microscopic examination (DME) are commonly used to determine Demodex mites density (Dd). However, no study has previously compared these two methods with respect to clinical types and distribution patterns of demodicosis. OBJECTIVE: The aim of this study was to compare the value of SSSB and DME findings in reference to the clinical types and distribution patterns of demodicosis. METHODS: The medical records of 35 patients diagnosed with demodicosis between December 2011 and June 2015 were retrospectively reviewed. Demodicosis was classified according to four clinical types (pityriasis folliculorum, rosacea type, acne type, and perioral type) and three distribution patterns (diffuse pattern, U-zone pattern, and T-zone pattern). Two samples, one for SSSB and one for DME, were obtained from a lesion of each patient. RESULTS: In all patients, mean Dd and the proportion with a high Dd (>5D/cm²) by DME (14.5±3.3, 80.0%, respectively) were higher than by SSSB (5.5±1.3, 37.1%, respectively; p<0.01, p=0.02, respectively). In terms of clinical types, for rosacea type, mean Dd and proportion with a high Dd by DME (12.4±3.5, 84.6%, respectively) were significantly greater than those determined by SSSB (3.6±1.2, 23.1%; p=0.04, p=0.04, respectively). In terms of distribution pattern, for the diffuse pattern, mean Dd and the proportion with a high Dd by DME (17.5±3.7, 100%, respectively) were significantly higher than those determined by SSSB (6.0±2.7, 26.7%; p<0.01, p<0.01, respectively). CONCLUSION: The results of our study revealed that DME is a more sensitive method for detecting Demodex than SSSB, especially in patients with diffuse pattern and suspected rosacea type. Further research is needed to confirm this finding.

Characteristics of Triatomine infestation and natural Trypanosoma cruzi infection in the State of Rio Grande do Norte, Brazil

Abstract: INTRODUCTION Natural and artificial ecotope infestation by the kissing bug triatomines and their colonization and infection by Trypanosoma cruzi , the Chagas disease agent, were evaluated in nine municipalities of the State of Rio Grande do Norte, Brazil. METHODS Following identification, triatomine intestinal contents were analyzed by direct microscopic examination, xenoculture, and polymerase chain reaction (PCR) for parasite detection. Trypanosoma cruzi isolates were genotyped using three different markers. RESULTS Of 842 triatomines captured, 65% were Triatoma brasiliensis , 17.8% Triatoma pseudomaculata , 12.5% Panstrongylus lutzi , and 4.7% Rhodnius nasutus . Triatoma brasiliensis and P. lutzi adults were found in the intradomicile. T. brasiliensis, T. pseudomaculata , and R. nasutus nymphs and adults were found in the peridomicile and wild environment. Intradomiciliary and peridomiciliary infestation indexes were 5.6% and 33.7%, respectively. In the peridomicile, chicken coops were the most infested ecotope. The T. cruzi triatomine infection rate was 30.2%, of which PCR detected 29%. P . lutzi (78.1%), T . brasiliensis (24.5%), and T . pseudomaculata (22.7%) were the most infected species. TcII and III genotypes were detected in T. brasiliensis and TcIII in P. lutzi . CONCLUSIONS T. brasiliensis was found in all environments and most ecotopes with high T. cruzi infection rates. High infection rates were also detected in T . pseudomaculata and P. lutzi , suggesting their role in the interchange between the wild and peridomestic transmission cycles. The combination of PCR, microscopic examination, and xenoculture contributed to improving T. cruzi infection evaluation in triatomine bugs. The TcII and TcIII genotypes were predominant in the study area.

Frecuencia de parásitos intestinales y evaluación de métodos para su diagnóstico en una comunidad marginal de Medellín, Colombia / Frequency of intestinal parasites and evaluation of methods for their diagnosis in a marginal community of Medellin, Colombia

Introducción: las parasitosis intestinales siguen siendo un problema de salud pública, que ha sido poco estudiado en Medellín, Colombia. Objetivo: determinar la frecuencia de parasitismo intestinal en habitantes de una comunidad marginal de Medellín y evaluar la validez, el desempeño, la eficiencia y la confiabilidad del examen directo en su diagnóstico. Materiales y métodos: estudio transversal y de evaluación de pruebas diagnósticas con fuente de información primaria. Se calcularon las proporciones con su intervalo de confianza y se hicieron pruebas de estadística no paramétrica y análisis de sensibilidad, especificidad, valores predictivos, razón de verosimilitud negativa y kappa. Resultados: la frecuencia global de parásitos, según el examen por concentración, fue 74,4%; la evaluación se hizo para parasitismo general y para las categorías protozoos, helmintos, comensales y patógenos; se hallaron sensibilidad superior al 68%, especificidad y valor predictivo positivo del 100%, valor predictivo negativo mayor de 74%, razón de verosimilitud negativa menor de 0,32, kappa superior a 0,77 y eficiencia superior al 90%. Conclusión: el problema del parasitismo intestinal amerita una pronta intervención por parte de las autoridades sanitarias dado que su frecuencia sigue siendo tan elevada como hace tres décadas y las pruebas disponibles para estudiarlo, incluyendo el examen directo de la materia fecal, tienen alto valor diagnóstico.

Background: Intestinal parasitism is still a public health problem. It has not been thoroughly studied in Medellin, Colombia. Objective: To determine the prevalence of intestinal parasites in residents of a marginal community in Medellin and to evaluate the validity, efficiency and reliability of direct examination in its diagnosis. Methods:Cross-sectional study and evaluation of diagnostic tests. Data were collected from a primary information source. Proportions with their confidence intervals were calculated; non-parametric statistical tests and analysis of sensitivity, specificity, predictive values, negative likelihood ratio and kappa were done. Results: Prevalence of parasites, according to the results of the concentration test, was 74.4%. Evaluation was done for intestinal parasites in general and for the following categories: protozoa, helminthes, commensals and pathogens. Sensitivity war over 68%, specificity and positive predictive value were 100%, negative predictive value was over 74%, negative likelihood ratio was less than 0.32, kappa was greater than 0.77 and efficiency was over 90%. Conclusion: Prevalence of intestinal parasitism is as high as it was three decades ago; its solution needs prompt and effective intervention of health authorities. The tests available for its study, including direct examination of stools, are of high diagnostic value.

Onicomicosis: epidemiología, agentes causales y evaluación de los métodos diagnósticos de laboratorio / Onychomycoses: epidemiology, causative agents and assessment of diagnostic laboratory methods

Desde marzo de 2007 hasta marzo de 2011 se estudiaron prospectivamente 414 pacientes con onicodistrofias en un laboratorio privado de Esquel. La prevalencia de onicomicosis de pie fue del 78 %; la de mano, del 58 %. Los principales agentes etiológicos fueron Trichophyton rubrum, Candida spp. y Trichophyton mentagrophytes. El desarrollo de dermatofitos prevaleció en las onicopatías de pie y el de Candida spp. en las de uñas de mano (ambos, p < 0,05). En las onicomicosis candidiásicas predominaron especies diferentes a Candida albicans. Las onicomicosis fueron más frecuentes en los hombres que en las mujeres. A su vez, en los hombres hubo más aislamientos de T. rubrum en pies (p < 0,05) y mayor proporción de exámenes directos (ED) y cultivos positivos (ambos, p < 0,05). La correlación entre los resultados del ED y del cultivo fue del 68 %. El rédito de ambos métodos se asoció a un mayor tamaño de la lesión ungueal. El ED fue más efectivo en onicodistrofias que superaban los 5 años de evolución. La positividad del cultivo fue independiente de la cronicidad de la onicodistrofia.

Since March 2007 to March 2011, 414 patients with onychopathies were prospectively analyzed. Prevalence of the toenail and fingernail mycoses was 78 % and 58 %, respectively. The major etiological agents were Trichophyton rubrum, Candida spp. and Trichophyton mentagrophytes. Dermatophytes were more frequently cultured from toenails, whereas Candida spp. from fingernails (both, p < 0.05). In candidal onychomycosis, species different from C. albicans were prevalent. A higher prevalence of toenail and fingernail mycoses, a predominance of T. rubrum in toenails (p < 0.05), and greater positivity in the direct examination (DE) and in culture (both, p < 0.05) were more frequently observed in men than in women. The correlation between DE and culture was 68 %. DE and culture yields were associated with a greater size lesion. DE was more effective in onycodystrophies with duration of more than 5 years. Culture positivity was independent of nail affection chronicity.

Invasive Fungal Infections: Diagnosis and Treatments in China / 대한의진균학회지

The body location and clinical appearance of fungal infections depends on the fungal virulence, infectious route and host immunological state. The result being that patients with mycoses consult with different clinical departments. The diagnosis of mycoses is based on the detection of fungal elements such as hyphae and/or yeast cells from the involved tissues. Isolation of the fungus is the precondition for species identification and antifungal treatment. To think clinically and to emphasize the mycology is the basic consideration of medical mycology research. Mycologists play a key role in the collaboration between the clinical and laboratory aspects. The clinician always wants to know what the fungus is and how to treatment the mycosis. Fungal pathogens are often stealthy and difficult to detect in infected patients during the early stages of the diseases and this is when therapies would be the most effective. Routine techniques commonly employed in the detection of fungal diseases including microscopic examination, culturing and serology are seriously hampered by lengthy waits of times for results and low accuracy. The clinician may want prophylaxis or to use empirical antifungal treatment to see if it does/does not work. The problem is that some of the patients do not respond to the antifungal treatment, because the doctor lacked sufficient evidence of fungus infection to give the doctor confidence to continue treatment. Accurate and early diagnosis of fungal diseases is critical for managing mycotic diseases. This is usually done by direct microscopic examination (DME) of KOH preparations. Good specimens are the key point that directly affects the quality of microscopic evidence and culture. The most important aspect is culturing samples on different media with or without chloramphenicol and cycloheximide and incubated at room temperature and 37degrees C. Early treatment could save a patient's life. We start treatment at the time we have the proof of fungal infection, i.e., KOH positive. Itraconazole, fluconazole, terbinafine, amphotericin B or its liposome form, can be used alone or in combination based on the fungal species involved and the site of infection.