RESUMO
Two of the methodical approaches for detection of virus contamination of surface waters were experimentally tested, i.e., the method of adsorption of virus particles to an inorganic salt (CaHPO4) and the ultrafiltration method using the Amicon apparatus. Under the given experimental conditions, the two methods showed practically identical factors of efficiency of virus concentration; the Danube river water proved to be a more suitable medium for the model of Coxsackie A4 virus than the physiological saline used as the control. In view of the feasibility, inexpensiveness and adequate effectivity of the precipitation method and with respect to good results obtained with it in field studies, the mentioned method of concentration could be recommended as the method of choice in field virological practice for aimed examination of surface waters.
