RESUMO
Human sapovirus has been shown to be one of the most important etiologies in pediatric patients with acute diarrhea. However, very limited data are available about the causative roles and epidemiology of sapovirus in community settings. A nested matched case-control study within a birth cohort study of acute diarrhea in a peri-urban community in Peru from 2007 to 2010 was conducted to investigate the attributable fraction (AF) and genetic diversity of sapovirus. By quantitative reverse transcription-real-time PCR (qPCR) sapovirus was detected in 12.4% (37/299) of diarrheal and 5.7% (17/300) of nondiarrheal stools (P = 0.004). The sapovirus AF (7.1%) was higher in the second year (13.2%) than in the first year (1.4%) of life of children. Ten known genotypes and one novel cluster (n = 5) within four genogroups (GI, GII, GIV, and GV) were identified by phylogenetic analysis of a partial VP1 gene. Further sequence analysis of the full VP1 gene revealed a possible novel genotype, tentatively named GII.8. Notably, symptomatic reinfections with different genotypes within the same (n = 3) or different (n = 5) genogroups were observed in eight children. Sapovirus exhibited a high attributable burden for acute gastroenteritis, especially in the second year of life, of children in a Peruvian community. Further large-scale studies are needed to understand better the global burden, genetic diversity, and repeated infections of sapovirus.
Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Sapovirus/isolamento & purificação , Estudos de Casos e Controles , Estudos de Coortes , Diarreia/epidemiologia , Diarreia/virologia , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Peru/epidemiologia , Filogenia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sapovirus/classificação , Sapovirus/genética , Análise de Sequência de DNA , População SuburbanaRESUMO
OBJECTIVES: To implement a system for remote diagnosis of tuberculosis and multidrug resistance (MDR) using the Microscopic-Observation Drug Susceptibility Assay (MODS) method in the Mycobacteria Laboratory, Trujillo Center of Excellence in Tuberculosis (CENEX-Trujillo). The system included a variant of an algorithm for recognition of Mycobacterium tuberculosis recently reported from digital images of MODS cultures of sputum samples. MATERIALS AND METHODS: The recognition algorithm was optimized using a retraining statistical model based on digital images of MODS cultures from CENEX-Trujillo. Images of 50 positive MODS cultures of patients with suspected multidrug-resistant tuberculosis were obtained between January and October 2012 in the CENEX-Trujillo. RESULTS: The sensitivity and specificity to recognize strings of tuberculosis were 92.04% and 94.93% respectively using objects. The sensitivity and specificity to determine a positive tuberculosis field were 95.4% and 98.07% respectively using pictures. CONCLUSIONS: The results demonstrated the feasibility of the implementation of telediagnostics in remote locations, which may contribute to the early detection of multidrug-resistant tuberculosis by MODS method.
Assuntos
Telemedicina , Tuberculose/diagnóstico , Algoritmos , Técnicas Bacteriológicas , Diagnóstico por Imagem , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/crescimento & desenvolvimento , Peru , Tuberculose Resistente a Múltiplos Medicamentos/diagnósticoRESUMO
Objetivos. Implementar un sistema para el diagnóstico remoto de tuberculosis y multidrogorresistencia (MDR) usando el método Microscopic-Observation Drug Susceptibility Assay (MODS) en el Laboratorio de Micobacterias del Centro de Excelencia en Tuberculosis de Trujillo (CENEX-Trujillo). El sistema incluyó una variante de un algoritmo de reconocimiento de Mycobacterium tuberculosis recientemente reportado a partir de imágenes digitales de cultivos MODS de muestras de esputo. Materiales y métodos. Se optimizó un algoritmo de reconocimiento por medio de un reentrenamiento del modelo estadístico basado en imágenes digitales de cultivos MODS provenientes del Laboratorio de Micobacterias del CENEX-Trujillo. Se obtuvieron imágenes de 50 cultivos MODS positivos de pacientes con sospecha de tuberculosis multidrogorresistente entre enero y octubre de 2012 en el CENEX-Trujillo. Resultados. La sensibilidad y la especificidad en objetos, para reconocer cordones de tuberculosis fueron de 92,04% y de 94,93% respectivamente. La sensibilidad y la especificidad en foto, para determinar un campo positivo a tuberculoisis fueron 95,4% y de 98,07% respectivamente. Conclusiones. Los resultados demostraron la factibilidad de la implementación de telediagnóstico en lugares remotos, el cual puede contribuir con la detección temprana de tuberculosis multidrogorresistente mediante el método MODS...
Objectives. To implement a system for remote diagnosis of tuberculosis and multidrug resistance (MDR) using the Microscopic-Observation Drug Susceptibility Assay (MODS) method in the Mycobacteria Laboratory, Trujillo Center of Excellence in Tuberculosis (CENEX-Trujillo). The system included a variant of an algorithm for recognition of Mycobacterium tuberculosis recently reported from digital images of MODS cultures of sputum samples. Materials and methods. The recognition algorithm was optimized using a retraining statistical model based on digital images of MODS cultures from CENEX-Trujillo. Images of 50 positive MODS cultures of patients with suspected multidrug-resistant tuberculosis were obtained between January and October 2012 in the CENEX-Trujillo. Results. The sensitivity and specificity to recognize strings of tuberculosis were 92.04% and 94.93% respectively using objects. The sensitivity and specificity to determine a positive tuberculosis field were 95.4% and 98.07% respectively using pictures. Conclusions. The results demonstrated the feasibility of the implementation of telediagnostics in remote locations, which may contribute to the early detection of multidrug-resistant tuberculosis by MODS method...
Assuntos
Humanos , Insuficiência de Múltiplos Órgãos , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , PeruRESUMO
Tuberculosis control efforts are hampered by a mismatch in diagnostic technology: modern optimal diagnostic tests are least available in poor areas where they are needed most. Lack of adequate early diagnostics and MDR detection is a critical problem in control efforts. The Microscopic Observation Drug Susceptibility (MODS) assay uses visual recognition of cording patterns from Mycobacterium tuberculosis (MTB) to diagnose tuberculosis infection and drug susceptibility directly from a sputum sample in 7-10 days with a low cost. An important limitation that laboratories in the developing world face in MODS implementation is the presence of permanent technical staff with expertise in reading MODS. We developed a pattern recognition algorithm to automatically interpret MODS results from digital images. The algorithm using image processing, feature extraction and pattern recognition determined geometrical and illumination features used in an object-model and a photo-model to classify TB-positive images. 765 MODS digital photos were processed. The single-object model identified MTB (96.9% sensitivity and 96.3% specificity) and was able to discriminate non-tuberculous mycobacteria with a high specificity (97.1% M. avium, 99.1% M. chelonae, and 93.8% M. kansasii). The photo model identified TB-positive samples with 99.1% sensitivity and 99.7% specificity. This algorithm is a valuable tool that will enable automatic remote diagnosis using Internet or cellphone telephony. The use of this algorithm and its further implementation in a telediagnostics platform will contribute to both faster TB detection and MDR TB determination leading to an earlier initiation of appropriate treatment.