ABSTRACT
For the detection of Enterovirus, we devised a direct economical method of polymerase chain reaction which does not require a previous extraction of ribonucleic acid and uses infected cell culture supernatants. The system was developed on the basis of universal primers of Enterovirus and specific primers of vaccinal strain Sabin 1. The achieved results proved that the non-existence of methods of RNA extraction and purification prior to the reaction does not affect the susceptibility and specificity of the system, in the rapid detection of Enterovirus genomes and identification of vaccinal strains of poliovirus.
Subject(s)
Humans , Enterovirus , Polymerase Chain Reaction/methods , Base Sequence , DNA, Viral , Enterovirus , Enterovirus Infections/diagnosis , Enterovirus Infections/virology , Meningoencephalitis , Molecular Sequence Data , RNA, Viral , Sensitivity and SpecificityABSTRACT
This paper reported the appraisal of a novel technology for the detection of enterovirus in sewage based on a viral recovery method using polyethylenglycol as a concentrating agent and on the combined use of viral isolation and polymerase chain reaction as viral detection and identification techniques. It was also confirmed that the viral recovery method is highly efficient since it allows to recover all viruses present in sewage and to preserve their infective capacity. It was proved that the polymerase chain reaction (PCR) is less sensitive than cell culture for detecting enteroviruses in sewage. It is also possible to use guadinine isothiocyanate, whose components can be prepared in the lab, as an alternative method for taking out and purifying nucleic acids instead of using the conventional TRIZOL method which is the one recommended in these cases by the World Health Organization.
Subject(s)
Wastewater/virology , Enterovirus , Evaluation Study , VirologyABSTRACT
La vacuna antisarampionosa se empezó a usar en Cuba en 1971. En los años setenta se implantó una estrategia inicial para el control del sarampión, y a ella le siguieron iniciativas adicionales a principios de los años ochenta. Pese a haberse mejorado el programa de control, siguieron produciéndose brotes de la enfermedad. En 1986, después de revisar las experiencias recogidas a partir de las iniciativas de control ya establecidas, se adoptó una nueva estrategia de vacunación antisarampionosa. Con el tiempo, la nueva estrategia de vacunación contra el sarampión llegó a tener tres componentes principales: primero, una campaña única de vacunación de "puesta al día" dirigida a niños de 1 a 14 años de edad. Segundo, se procuró lograr y mantener una alta cobertura con la vacuna mediante el ofrecimiento de servicios de vacunación obligatoria para niños de 12 meses de edad ("vacunación de mantenimiento"). Por último, se llevaron a cabo periódicamente campañas de "seguimiento" para niños de 2 a 6 años de edad. Con el fin de monitorear el territorio recorrido hacia le eliminación del sarampión, se ha hecho un esfuerzo por fortalecer la vigilancia de la enfermedad, de la cual forma parte la investigación de casos sospechados. Tanto la campaña general de "puesta al día" como la de "seguimiento" alcanzaron coberturas de más de 98% en los grupos de edad a los que fueron dirigidas. El programa de vacunación de rutina también ha mantenido una alta cobertura. La alta inmunidad poblacional contra el sarampión lograda mediante estas estrategias de vacunación dio por resultado una rápida reducción de la incidencia de la enfermedad. De 1989 a 1992, se notificaron menos de 20 casos anuales confirmados por laboratorios. En Cuba, el último caso confirmado por pruebas serológicas se presentó en julio de 1993. La estrategia para la eliminación del sarampión que se ha aplicado en Cuba ha interrumpido la transmisión de la enfermedad y ha impedido la circulación...
The vaccine against measles came into use in Cuba in 1971. During the seventies, a new early strategy for measles control was established, and it was followed by further efforts in the early eighties. Despite improvements to the control program, disease outbreaks continued to occur. In 1986, after examining the experience acquired through the control initiatives that were already in place, a new measles vaccination strategy was adopted. In time, the new vaccination strategy against measles came to have three main components: first, a single vaccination "catching-up" campaign targeting children 1 to 14 years of age. Second, efforts were made to achieve and maintain high vaccine coverage through mandatory vaccination services for 12-month-old children ("maintenance vaccination"). Finally, periodic "follow-up" campaigns were carried out for children 2 to 6 years of age. Steps were taken, for the purpose of monitoring the progress made so far toward eliminating measles, to strengthen disease surveillance systems, including the screening of suspected cases. The "catching-up" and "follow-up" campaigns both achieved greater than 98% coverage within targeted age groups. The routine vaccination program has also maintained high coverage. The high population immunity against measles that has been attained through these vaccination strategies has resulted in a rapid decrease in the incidence of the disease. From 1989 to 1992, less than 20 laboratory-confirmed cases were reported annually. In Cuba, the last case confirmed through serologic screening was reported in July 1993. Cuba's strategy for measles elimination has interrupted disease transmission and kept the causal virus from circulating on the island. Cuba's experience with measles elimination suggests that if an appropriate vaccination strategy is applied, measles can be globally eradicated.