C.D.C. report finds increase in salmonella infections
June 21, 2011
by Jay Sjerven
infections have not decreased during the past 15 years and instead have increased by 10%, according to “Vital Signs,” a report issued by the Centers for Disease Control and Prevention. During the same period, the report noted, illnesses caused by pathogens such as E. coli
O157 have declined nearly 50%, and the overall rates of six food-borne infections have been reduced by 23%.
“Although food-borne infections have decreased by nearly one-fourth in the past 15 years, more than 1 million people in this country become ill from salmonella
each year, and salmonella
accounts for about half of the hospitalizations and deaths among the nine food-borne illnesses C.D.C. tracks through FoodNet,” said Thomas R. Frieden, director of the C.D.C. “Salmonella
costs hundreds of millions of dollars in direct medical costs each year. Continued investments are essential to detect, investigate, and stop outbreaks promptly in order to protect our food supply.”
The Vital Signs report summarized 2010 data from the C.D.C.’s Foodborne Diseases Active Surveillance Network (FoodNet).
In 2010, FoodNet sites, which include about 15% of the American population, reported nearly 20,000 illnesses, 4,200 hospitalizations and 68 deaths from nine food-borne infections. Of those, salmonella
caused more than 8,200 infections, nearly 2,300 hospitalizations and 29 deaths (54% of the total hospitalizations and 43% of the total deaths reported through FoodNet). The C.D.C. estimated there are 29 infections for every lab-confirmed salmonella
The rate of E. coli
O157 cases reported by FoodNet sites was two cases per 100,000 people in 1997 and, by 2010, had decreased to 0.9 cases per 100,000 people. The nearly 50% reduction in E. coli
O157 incidence was considered significant when compared with the lack of change in salmonella
The C.D.C. credited the reduction in E. coli
to improved detection and investigation of outbreaks through the C.D.C.’s PulseNet surveillance system, cleaner slaughter methods, testing of ground beef for E. coli
, better inspections of ground beef processing plants, regulatory improvements like the prohibition of STEC O157 in ground beef and increased awareness by consumers and restaurant employees of the importance of properly cooking beef.
“Thanks to our prevention-based approach to food safety, as well as industry and consumer efforts, we have substantially reduced E. coli
O157 illnesses,” said Elisabeth Hagen, undersecretary for food safety in the U.S. Department of Agriculture. “This report demonstrates that we’ve made great progress. However, far too many people still get sick from the food they eat, so we have more work to do. That is why we are looking at all options, from farm to table, in-order to make food safer and prevent illnesses from E. coli
, and other harmful pathogens.”
Vital Signs identified what the C.D.C. considers the principal difficulties encountered in controlling salmonella
may be found in many different types of foods, including meats, eggs, fruits, vegetables and even processed foods such as peanut butter, and contamination with salmonella may occur virtually anywhere from fields where food is grown to home kitchens. Foods often come from a few central locations that are widely distributed, which means salmonella
-related sickness may spread quickly. People eat more food away from home, and more food ingredients come from around the world. Also, some policies and procedures that may make a difference in reducing salmonella
contamination may take years to implement.
To reduce salmonella
contamination, C.D.C. outlined a number of important steps that must be taken. The C.D.C. said “strong and specific action” to identify and prevent contamination from the farm to the table was essential, asserting this was a primary lesson learned in successfully reducing E. coli
O157 infection. Most important, new prevention strategies must be developed for foods most at risk for contamination, and those strategies must embrace measures to be implemented both before and after harvesting.
Poultry accounts for 29% of salmonella
-related illness outbreaks, and eggs count for another 18%. With regard to eggs specifically, the C.D.C. advised preventive controls for egg producers such as buying chicks from suppliers with salmonella enteriditis
control programs, testing poultry houses for salmonella enteritidis
and setting temperatures requirements for storing and transporting eggs.
The Vital Signs report indicated other pathogens included in the overall 2010 rate reduction of 23% when compared with 1996-1998 were: campylobacter, E. coli
STEC O157, listeria
, vibrio and yersinia. In contrast, rates of vibrio infection were 115% higher than in 1996-1998, and 39% higher than in 2006-2008. Most vibrio infections are the result of eating raw or undercooked shellfish.
The full report may be viewed by visiting www.cdc.gov/vitalsigns/