RESUMEN
We report a molecular epidemiological study of rabies virus (RABV) strains circulating in animal populations in Bhutan, and investigate potential origins of these viruses. Twenty-three RABV isolates originating from dogs and other domestic animals were characterized by sequencing the partial nucleoprotein (N) gene (395 bp). Phylogenetic analysis was conducted and the Bhutanese isolates were compared with rabies viruses originating from other parts of the world. Phylogenetic analysis showed that Bhutanese isolates were highly similar and were closely related to Indian strains and South Asian Arctic-like-1 viruses. Our study suggests that the rabies viruses spreading in southern parts of Bhutan have originated from a common ancestor, perhaps from the Indian virus strain.
Asunto(s)
Enfermedades de los Bovinos/epidemiología , Enfermedades de los Perros/epidemiología , Virus de la Rabia/clasificación , Virus de la Rabia/aislamiento & purificación , Rabia/veterinaria , Enfermedades de los Porcinos/epidemiología , Animales , Bután/epidemiología , Bovinos , Enfermedades de los Bovinos/virología , Análisis por Conglomerados , Enfermedades de los Perros/virología , Perros , Genotipo , Epidemiología Molecular , Datos de Secuencia Molecular , Proteínas de la Nucleocápside/genética , Filogenia , Rabia/epidemiología , Rabia/virología , Virus de la Rabia/genética , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
BACKGROUND: Necrotising non-granulomatous lymphadenitis can be observed in several conditions, most notably infection (including tuberculosis, yersiniosis and nocardiasis), Kikuchi-Fujimoto disease and systemic lupus erythematosus. AIMS: To evaluate the role of PCR in the detection of Mycobacterium tuberculosis in necrotising non-granulomatous lymphadenitis in Thai patients using formalin-fixed paraffin-embedded tissue. METHODS: 35 patient samples showing necrotising non-granulomatous lymphadenitis were subjected to PCR for detection of the IS6110 sequence of M tuberculosis. For comparison, sections were visually assessed for acid-fast bacilli using the Ziehl-Neelsen stain. RESULTS: Among 35 cases of necrotising non-granulomatous lymphadenitis, a conclusive diagnosis could be reached in 23 cases: 15 cases of Kikuchi-Fujimoto disease, 6 of tuberculosis and 2 of systemic lupus erythematosus. Of the 6 cases of tuberculous lymphadenitis, 4 (66.6%) were detected by PCR in formalin-fixed paraffin-embedded tissue samples. PCR was positive in 6/12 of the remaining cases (50%) in which a definitive diagnosis could not be reached by other methods. CONCLUSION: Using PCR, a significant percentage (28%) of cases of necrotising non-granulomatous lymphadenitis in this study could be attributed to M tuberculosis. PCR for identification of the organism can be extremely helpful in confirming a diagnosis of tuberculosis when Ziehl-Neelsen staining is negative.
Asunto(s)
Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Ganglionar/diagnóstico , Adolescente , Adulto , Biopsia , ADN Bacteriano/aislamiento & purificación , Femenino , Formaldehído , Humanos , Ganglios Linfáticos/patología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Necrosis , Neutrófilos/patología , Adhesión en Parafina , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Tuberculosis Ganglionar/patología , Adulto JovenRESUMEN
Rabies caused by fox bite is uncommon, most cases being caused by bite of rabid dogs (95%). We report a 45-year-old lady with rabies encephalomyelitis caused by bite of a rabid wild fox (Vulpes vulpes), a species prevalent in the Deccan plateaus of Central India. Though foxes are known to be susceptible to rabies, literature on the pathological changes caused by fox bite rabies in humans is scarce. Unlike the mild histological alterations described in canine rabies, a florid encephalitic process evolved in fox bite rabies, in our case, with intense microglial reaction, neuronophagia and perivascular inflammatory infiltrates despite clinical manifestation as a paralytic rabies. Immunostaining using polyclonal antibodies to the rabies viral nucleocapsid antigen and to the whole virion demonstrated high viral load within neurons with extensive spread along dendritic arborization and axonal tracts. Genomic sequence analysis demonstrated close homology with canine virus strain with only minor variations.
Asunto(s)
Mordeduras y Picaduras , Encéfalo/patología , Encefalitis Viral/patología , Zorros/virología , Rabia/patología , Animales , Animales Salvajes/virología , Encéfalo/metabolismo , Encéfalo/ultraestructura , Encefalitis Viral/etiología , Femenino , Humanos , Inmunohistoquímica , Microscopía Electrónica de Transmisión , Microscopía Inmunoelectrónica , Persona de Mediana Edad , Neuronas/metabolismo , Neuronas/patología , Neuronas/ultraestructura , Rabia/complicacionesRESUMEN
Current serological tests do not reliably diagnose rabies. We describe a technique based on amplification of nucleic-acid sequences to detect rabies-specific RNA in the saliva and cerebrospinal fluid (CSF) of four living patients with rabies. Rabies RNA could be detected in either saliva or CSF, or both, in all patients and as early as day 2 after onset of symptoms. Both saliva and CSF should be serially tested because not every sample can be expected to be positive. The whole process, including automated extraction, isothermal amplification, and detection can be done within 4 h.