Numbers are usually called trends after a year.  After more than a decade, numbers can point up real problems or they just become more interesting.

That may be why FoodNet, the collaborative 10-state surveillance program, took a step back 

from its annual “Vital Signs” report to fill an entire supplemental issue of the journal Clinical Infectious Diseases to examine more than a decade’s worth of data.

Like its last annual report, the supplemental also finds Salmonella to be on fire in the U.S.

Led by the federal Centers for Disease Control and Prevention (CDC) in Atlanta, FoodNet connects 10 state health departments with CDC, the U.S. Food and Drug Administration (FDA) and USDA’s Food Safety and Inspection Service (FSIS).

FoodNet, with its ability to identify and monitor the incidents of foodborne illness with active population-based surveillance and laboratory-confirmed analysis, is stepping out of the moment with these findings:

– Salmonella Enteritidis (SE) infections are on the rise in the United States, and chickens and eggs are likely the major sources. SE is the most common of about 40 strains of Salmonella that are found in the U.S. Led by cases among children, older people and residents in southern FoodNet sites, the incidence of SE infections has risen 44 percent.

– Progress has slowed when it comes to the frequency of the seven most common foodborne diseases.  Incidents of Campylobacter, Listeria, Salmonella, Shiga toxin-producing E. coli (STEC) O157, Yersinia and Vibrio illness were 23 percent lower in 2010 than 1996-1998.  But similar progress was not made when comparing 2010 to the more recent 2006-2008 period.

– Fourteen percent of the most common foodborne diseases are linked to contact with animals. A total of 445,213 cases involved direct contact with wild animals, pets or other animals such as livestock, including contact with their feces, bodily fluids and environment. The popularity of backyard chickens has posed a particular risk. Campylobacter, Salmonella, and Cryptosporidium cause the most human deaths and hospitalizations in infections related to animal contact.

– Men eat more meat than women and women eat more fruits and vegetables than men.    Men are more likely to eat such “high risk” foods as undercooked hamburger, raw oysters, and runny eggs. Woman are more likely to eat only one high risk food: alfalfa sprouts.

– The frequency of vibriosis increased in the U.S. from 1996 to 2010, pointing to the need for more public education about the dangers of raw shellfish consumption and measures to  reduce oyster contamination.

– Incidence of listeriosis did not change between 2004 and 2009, and prevention efforts are needed for women, especially Hispanics, and older adults.   Those groups have a higher risk of invasive diseases including bloodstream infection, meningitis, miscarriage and stillbirth.

– By 2009, the number of Yersinia enterocolitica infections first measured in 1996 fell off sharply, especially among young black children in Georgia who were the focus of education programs.

– Campylobacter is the most common cause of traveler foodborne illness in those returning from overseas. The greatest risk is from travel to Africa, but in numbers most travel-associated infections were in travelers who had been in Latin America and the Caribbean.

– FoodNet is successful in identifying the food responsible for an outbreak 32 percent of the time. It successfully finds the responsible bacteria or virus about 60 percent of the time.   Outbreaks that go unsolved, with neither the food or cause found, involved too few patients, stool samples, or control subjects.

– In a survey, physicians’ knowledge of Shiga-toxin producing E. coli (STEC) infections was found by FoodNet to be low, pointing up the need for both education and interventions to ensure that those infected are properly treated.

FoodNet states include: Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, Tennessee and selected counties in California, Colorado, and New York (see map above). The 10 participating areas represent about 15 percent of the U.S. population.

“The FoodNet program shows the impact that high-quality, nationally coordinated surveillance can have on public health and policy,” wrote Elaine Scallan and Barbara E. Mahon in the supplemental issue’s main article. Scallan is with the Colorado School of Public Health, and Mahon is deputy chief of CDC’s Enteric Diseases Epidemiology Branch.

————————–

CDC image of the FoodNet states