March 2, 2009

River water might be salmonella source

A U.S. study suggests health officials investigating salmonella illnesses consider untreated river surface water as a possible source of contamination.

University of Georgia researchers tested water in rivers and streams in an area of Georgia known for its high rate of sporadic salmonella cases. The team found the bacteria in 79 percent of water samples, with the highest concentrations and the greatest diversity of strains occurring during the summer and after rainfall.

Streams are not routinely tested for salmonella and our finding is an indication that many more could be contaminated than people realize, said Associate Professor Erin Lipp, who co-wrote the study with former graduate student Bradd Haley and Dana Cole of the Georgia Division of Public Health.

She said understanding environmental factors that contribute to salmonella illnesses can guide people in the proper construction and maintenance of wells, basic hygiene such as hand washing and good food safety practices.

We also have the potential to decrease the likelihood of larger outbreaks related to produce, because in many cases contaminated irrigation water and not the produce itself, may be the cause of the outbreak, Lipp added.

The research appears in the journal Applied and Environmental Microbiology.