Human Salmonella infections have increased 10 percent in recent years, in contrast to an overall decline in foodborne illness, the Centers for Disease Control and Prevention (CDC) reported this week.

“Although foodborne 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 foodborne illnesses CDC tracks through FoodNet,” said CDC Director Thomas R. Frieden, M.D., M.P.H.  “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 CDC report in the latest issue of its Morbidity and Mortality Weekly Report covers a continuing study area in 10 states called FoodNet.  A total of 19,089 infections, 4,247 hospitalizations, and 68 deaths were reported from FoodNet sites in 2010, CDC said.  “Salmonella infection was the most common infection reported (17.6 illnesses per 100,000 persons) and was associated with the largest number of hospitalizations (2,290) and deaths (29); no significant change in incidence of Salmonella infection has occurred since the start of surveillance during 1996-1998,” when FoodNet was launched, CDC said.

The incidence of Salmonella in 2010 was significantly higher than during 2006—2008, with a 10- percent increase, CDC said.  Among the 7,564 Salmonella isolates for which serotyping results were obtained  (92 percent of total Salmonella isolated), the most common serotypes were Enteritidis (22 percent), Newport (14 percent), and Typhimurium (13 percent).

“Reducing Salmonella infection and other foodborne infections will require strong action to prevent food contamination at multiple steps along the farm to the table chain,” the CDC report said.

“CDC’s estimates show that there has been very little change in the prevalence of Salmonella-caused illness in humans in the last 15 years,” said Dr. Scott Russell, a microbiologist and scientific advisor to the National Chicken Council.  “Yet we know the presence of Salmonella on raw chicken meat has declined sharply in the last 15 years.  Chicken companies have done a very good job improving the microbiological profile of raw products, and consumers should continue to practice common-sense safe handling and preparation steps.  To further reduce human exposure to Salmonella, other sources, both food and non-food, should be examined more closely.”

Cases of Foodborne Illness Attributed to Salmonella and Campylobacter

Per 100,000 Population,

Foodborne Diseases Active Surveillance Network, United States, 1996-2010

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Campylobacter 23.5 25.2 21.4 17.5 15.7 13.8 13.4 12.6 12.9 12.7 12.7 12.8 12.7 12.3 13.6
Salmonella 14.5 13.6 12.3 13.6 14.4 15.1 16.1 14.5 14.7 14.5 14.8 14.9 16.2 15.2 17.6

Source: CDC