RESUMEN
La rubéola es una enfermedad infectocontagiosa que afecta a niños y adultos jóvenes, y cuando esta se produce en el primer trimestre del embarazo ocasiona malformaciones congénitas en el feto. En el Laboratorio Nacional de Referencia de Sarampión, Rubéola y Parotiditis del Instituto de Medicina Tropical Pedro Kourí, se realizó la detección del índice de avidez relativo (IAR) de la IgG en 15 pares de sueros correspondientes a igual número de pacientes adultos que enfermaron durante un brote de rubéola ocurrido en dos provincias de Cuba en el 2004, los cuales fueron positivos a anticuerpos de tipo IgM específicos al virus, y en algunos se encontró seroconversión o un aumento de cuatro veces el título entre los sueros de la fase aguda y convaleciente con la técnica de inhibición de la hemaglutinación. En 13 (86,6 por ciento) de los pacientes estudiados se detectó infección primaria, mientras que en dos (13,3 por ciento) de ellos la infección fue secundaria. La detección de la avidez de la IgG constituye un método alternativo útil para distinguir una infección primaria de una secundaria al virus de la rubéola y fortalece el diagnóstico de esta enfermedad en Cuba(AU)
Rubella infectious diseases affect children and young adults and when they occur during the first trimester of pregnancy, cause congenital malformations in the newborn. In the National Reference Laboratory (NLR) of measles, rubella and mumps from the Tropical Medicine Institute Pedro Kourí, the IgG Avidity Index (AI) detection was carried out to 15 paired serum samples, which corresponded to same number of patients infected with this virus in two Cuban provinces in 2004. The samples were positive to virus- specific IgM antibodies, in addition seroconversion or an increase of > 4 fold of the titers in the sera of the acute and convalescence phase using the hemagglutination inhibition assay (HIA). The AI value showed a primary infection to rubella virus in 13 (86.6 per cent) of the patients studied, and a secondary infection in 2 (13.3 percent) of them. The IgG avidity antibody detection is a reliable alternative tool for distinguishing between primary and secondary rubella virus infection and for strengthing the diagnosis of this disease in Cuba(AU)
Asunto(s)
Inmunización Pasiva , Sueros Inmunes , Rubéola (Sarampión Alemán)RESUMEN
Rabies is a neurotropic disease that is often lethal. The early diagnosis of rabies infection is important and requires methods that allow for the isolation of the virus from animals and humans. The present study compared a modified shell vial (MSV) procedure using 24-well tissue culture plates with the mouse inoculation test (MIT), which is considered the gold standard for rabies virus isolation. Thirty brain samples (25 positive and 5 negative by the fluorescent antibody test) obtained from different animal species at the National Institute of Hygiene Rafael Rangel in Caracas, Venezuela, were studied by the MIT and MSV assays. Nine samples (36%) were positive at 24 h, 10 (40%) were positive at 48 h and six (24%) were positive at 72 h by the MSV assay. With the MIT assay, 76% were positive at six days post inoculation and 12% were positive at 12 and 18 days post inoculation. One sample that was negative according to the MSV assay was positive with MIT on the 12th day. The MSV procedure exhibited a sensitivity of 96.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value 80%. This procedure allowed for rapid rabies virus detection. MIT can be employed as an alternative method in laboratories without tissue culture facilities.
Asunto(s)
Virus de la Rabia/aislamiento & purificación , Rabia/diagnóstico , Animales , Anticuerpos Antivirales , Gatos , Bovinos , Quirópteros , Perros , Técnica del Anticuerpo Fluorescente , Cabras , Humanos , Ratones , Virus de la Rabia/inmunología , Sensibilidad y Especificidad , Factores de Tiempo , Técnicas de Cultivo de TejidosRESUMEN
Rabies is a neurotropic disease that is often lethal. The early diagnosis of rabies infection is important and requires methods that allow for the isolation of the virus from animals and humans. The present study compared a modified shell vial (MSV) procedure using 24-well tissue culture plates with the mouse inoculation test (MIT), which is considered the gold standard for rabies virus isolation. Thirty brain samples (25 positive and 5 negative by the fluorescent antibody test) obtained from different animal species at the National Institute of Hygiene Rafael Rangel in Caracas, Venezuela, were studied by the MIT and MSV assays. Nine samples (36%) were positive at 24 h, 10 (40%) were positive at 48 h and six (24%) were positive at 72 h by the MSV assay. With the MIT assay, 76% were positive at six days post inoculation and 12% were positive at 12 and 18 days post inoculation. One sample that was negative according to the MSV assay was positive with MIT on the 12th day. The MSV procedure exhibited a sensitivity of 96.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value 80%. This procedure allowed for rapid rabies virus detection. MIT can be employed as an alternative method in laboratories without tissue culture facilities.
Asunto(s)
Animales , Gatos , Bovinos , Perros , Humanos , Ratones , Virus de la Rabia/aislamiento & purificación , Rabia/diagnóstico , Anticuerpos Antivirales , Quirópteros , Técnica del Anticuerpo Fluorescente , Cabras , Virus de la Rabia/inmunología , Sensibilidad y Especificidad , Factores de Tiempo , Técnicas de Cultivo de TejidosRESUMEN
To study human rotaviruses in Cuban children up to 5 years old with acute diarrhea, a total of 64 faecal samples from two pediatric hospitals between 2006 and 2008 were analyzed. Thirty-nine samples (60.9%) were found positive for rotaviruses by enzyme-linked immunosorbent assay (ELISA) and polyacrylamide gel electrophoresis (PAGE), while four (6.2%) exhibited discordant results (ELISA positives/PAGE negatives). All the positive samples were genotyped by a reverse transcription-polymerase chain reaction (RT-PCR). The most prevalent G and P types were G1 (60.5%) and P[8] (90.6%), respectively. Among the rotaviruses detected, two long RNA patterns were identified by PAGE (L/A and L/B). The predominant genotype in 2006 and 2007 was G1/P[8] with detection rates 71.4% and 80%, respectively. In contrast, G9/P[8] was found at the highest rate (78.5%) in 2008. The phylogenetic analysis of VP7 genes of the ten representative strains indicated that Cuban G1/P[8] rotaviruses were close to those reported in the Americas, and G9/P[8] rotaviruses were located in the lineage of the emerging G9 strains spreading worldwide. This is the first molecular epidemiologic study of rotaviruses in Cuba, highlighting the current increase of the G9 rotavirus which has been recognized globally as an emerging genotype. The study reinforces the need for a systematic surveillance of the molecular epidemiology of rotaviruses.