Occurrence of Viruses in Treated Drinking Water in the United States

Health concerns regarding waterborne transmission of enteric viruses began to develop around 1940 in the United States (U.S.) with the isolation of poliovirus from human feces and sewage. The implication of these isolations for the transmission of viral disease through contaminated drinking water stimulated research on methodology for virus detection, recovery and assessment from water. Although virus methods research is still an important area of study, relatively sensitive procedures became available during the past decade for recovering many enteric virus types from large-volume samples of drinking water. Controversy surrounded many of the early reported isolations of viruses from treated drinking water using these procedures due to the suspicion of laboratory contamination. The occurrence of viruses in drinking water treated by currently accepted procedures has still not been proven by the U.S. experience although the likelihood may be gaining support. However, a virus survey of 54 water supplies and extensive studies of two water systems by the U.S. Environmental Protection Agency did not demonstrate viral contamination of treated water derived from surface sources.