The study -- led by Dr. Timothy F. Jones of the Tennessee Department of Health in Nashville -- compared the dietary and environmental exposure of 442 infants who had been infected with Salmonella with those of 928 age-matched controls who had not been infected. The researchers examined the children's exposures in the five days prior to infection.
"Compared with healthy controls, infants with Salmonella infection were less likely to have been breastfed and more likely to have had exposure to reptiles, to have ridden in a shopping cart next to meat or poultry, or to have consumed concentrated liquid infant formula during the 5-day exposure period," the researchers wrote.
In infants 3 to 6 months and older, traveling outside the United States was associated with Salmonella infection, while children 6 months and older who attended day care with children who had diarrhea were more likely to be infected with Salmonella.
"Many of the risk factors identified in this study are potentially modifiable through targeted preventive education and behavioral change among the caretakers of infants," Jones and colleagues wrote in their report.
"Attention should be directed at developing practical and effective measures to prevent Salmonella infection in this high-risk population," they wrote.
Salmonella causes roughly 1.4 million illnesses and 400 deaths every year in the United States. According to Jones, Salmonella rates are highest in infants, and prior to his study, little was known about potential sources of infection.