Vigilancia ambiental de cepas de poliovirus en municipios considerados con potencial de riesgo para reintroducción de estos virus en la comunidad
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Gómez Hincapie, José Fernando | 2019-07-22
Abstract
The polio virus is an important pathogen that is transmitted through the fecal-oral route. The epidemiology of the infection is directly related to the access of the population to drinking water and to the sewage infrastructure, therefore epidemiological surveillance programs allow to maintain high standards of health safety in vulnerable populations. In this way, the impact on public health caused by the passage of irregular immigrants in local communities can be evaluated, as well as generating the development of contingency, sanitation and humanitarian support plans for people from countries where polio continues to be of a character endemic. In the present study, an environmental surveillance of poliovirus was carried out in three municipalities of Colombia: Cali, Turbo, Cúcuta, with high risk of transmission by flow of irregular migrants. Three serial samplings were carried out in the municipalities of Turbo, Cali and Cúcuta, from April to November of the year 2017, taken as the main discharge of wastewater from each municipality. The samples were transported to the Center for Biomedical Research of the University of Quindío and were concentrated using the "two phase" method, recommended by the World Health Organization (WHO). Then we proceeded to the viral isolation in RD and L20B cell lines, according to the WHO standard for reference laboratories. The samples that showed cytopathic effect (ECP) in both RD and L20B cells were extracted RNA, and then proceeded to the identification of the isolates, by means of an RT-PCR, using three sets of primers: EV, Pan PV, in addition to Sabin 1 and 3. Finally the product of the RT-PCR was verified, it was observed in a 2% agarose gel, and photographic record of the findings was left. In the results, four samples of wastewater were identified with the presence of bands with the expected size (114 bp) for enterovirus (EV) by RT-PCR; both the RD and L20B cell lines were able to isolate non-polio EV (EVNP). The processes of concentration, isolation and, finally, of intratypical differentiation were developed satisfactorily, since the presence of VOPb (Sabin 1 and 3) was identified during all the processes. The investigation allowed detecting the presence of EVNP in the residual water samples of the municipalities under study. No presence of poliovirus derived from the vaccine or wild poliovirus was found. As a recommendation, it is important that the surveillance system be active and maintain the sensitivity and high level of quality required by WHO, given the possibility of importing wild polioviruses or vaccine derivatives from endemic countries or with little control in their health programs.
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