The steep increase in reported cases of salmonella infections linked to contaminated tomatoes since June 10 is most likely due to better surveillance and reporting by state health departments, and has not been caused by a large number of new infections, Dr. Ian Williams, chief of the OutbreakNet Team for the U.S. Centers for Disease Control and Prevention, said during a recent media briefing.
“The number of reported ill persons increased markedly mainly because some states improved surveillance for salmonella in response to this outbreak, and because laboratory identifications of many previously submitted strains were completed,” Williams said. “And, just to make this point, the bulk of the new cases reported were from the state of Texas. State of Texas is now reporting 265 illnesses.
“Among the 281 persons for whom we have information available, the illnesses began on April 10 and range up to June 10.”
On June 7, the day the U.S. Food and Drug Administration expanded its tomato consumption warning nationwide, the CDC had reported a total of 161 illnesses and 23 hospitalizations — primarily in Texas and New Mexico — caused by Salmonella Saintpaul, a unique strain of the pathogen that has linked all of the cases in the outbreak.
Most food retailers destroyed existing supplies of red plum, red Roma and round red tomatoes during the next two days, and many national restaurant chains temporarily discontinued use of all tomatoes as a precaution.
Since then, the number of illnesses linked to the outbreak has risen to more than 550 in 32 states and the District of Columbia, but, as Williams explained, the cases that the CDC currently has information on only range up to June 10.
Traceback efforts are ongoing at the FDA. Agency officials said during the briefing that they have narrowed their search to specific farms in Florida and Mexico, but noted that it is highly unlikely that the contamination began in two locations at once. And there is still a possibility that the products were contaminated somewhere along the supply chain.
