FoodNet 2012 CID Supplement
2012 Supplement to Clinical Infectious Diseases
FoodNet tracks important foodborne illnesses and generates information that provides a foundation for food safety policy and prevention efforts. The 2012 Clinical Infectious Diseases FoodNet supplement, A Foundation for Food Safety in the United States, contains a variety of articles that provide new information on current issues. Together, they highlight FoodNet’s central role in US surveillance and investigation of foodborne disease. Regulators and other public health officials, consumer advocates, industry, and others need information on trends, high-risk populations, and the foods that cause illness so that interventions can be targeted most efficiently and effectively. The articles in this supplement are provided by FoodNet as part of its efforts to disseminate the results of its surveillance and analytic work.
- The overall frequency of illnesses caused by the six most common foodborne diseases (Campylobacter, Listeria, Salmonella, Shiga toxin-producing E. coli (STEC) O157, Yersinia, and Vibrio) was 23% lower in 2010 than in 1996-1998. However, a comparison of 2006-2008 to 2010 indicates that progress has slowed recently.
- Salmonella Enteritidis infections are a growing problem in the United States; chicken and eggs are likely major sources.
- Fourteen percent of the illnesses caused by the seven most common foodborne diseases are attributable to contact with animals.
FoodNet in 2012 – A Foundation for Food Safety in the United States: FoodNet’s high quality, nationally coordinated surveillance is important for public health and policy. The CID supplement was developed to go beyond FoodNet annual reports.
Calculating a Measure of Overall Change in the Incidence of Selected Laboratory-Confirmed Infections with Pathogens Transmitted Commonly through Food, Foodborne Diseases Active Surveillance Network (FoodNet), 1996–2010.
- The overall frequency of illnesses caused by Campylobacter, Listeria, Salmonella, Shiga toxin-producing E. coli (STEC) O157, Yersinia and Vibrio was 23% lower in 2010 than in 1996-1998. However, a decrease in incidence between 2006-2008 and 2010 of 3% indicates that progress has slowed recently.
- More men than women ate meat, and more women than men ate vegetables and fruits. Men were more likely to have consumed “high-risk” foods, such as undercooked hamburger, raw oysters and runny eggs. But only one high-risk food, alfalfa sprouts, was more frequently consumed by women.
- The food vehicle was determined in 32% of FoodNet outbreak investigations, although the etiology (bacteria or virus responsible for the outbreak) was found in 60% of outbreak investigations. Investigations that were not successful in determining the food or cause of the outbreak had too few patients ill, too few stool specimens to test or too few control subjects.
- Physicians were surveyed to measure their knowledge about Shiga toxin—producing E. coli (STEC) infections. The survey found that physician knowledge of STEC was low, showing a need for educational interventions to help ensure that physicians correctly identify, report, and treat cases of this foodborne illness.
- The number of Yersinia enterocolitica infections reported in FoodNet sites significantly decreased from 1996 to 2009. The biggest decrease was in young black children in Georgia, possibly a result of an educational campaign targeted to high-risk groups. The campaign included pamphlets on safe preparation and handling of chitterlings, particularly during the winter months and holidays.
Sources of Illness:
- Campylobacter is the most common cause of foodborne illness in travelers returning to the United States from overseas. Over half of all travel associated infections reported were in travelers to Latin America and the Caribbean. However, travel to Africa carried the greatest risk of travel associated infection (75.9 cases per 100,000 travelers).
- Fourteen percent of all illnesses (445,213 annually) caused by the 7 most common foodborne diseases are attributable to contact with animals: direct contact with wild animals, pets, and other animals, as well as indirect contact with the animal’s feces, bodily fluids or its environment. Campylobacter, Salmonella, and Cryptosporidium caused the majority of illnesses, hospitalizations and deaths attributed to contact with animals and their environments.
- There was no significant change in the incidence of listeriosis from 2004 to 2009. Increasing prevention efforts such as food safety education among pregnant women, especially those who are Hispanic, and older adults are recommended to substantially decrease overall rates of listeriosis.
- Older adults and pregnant women, especially Hispanics, have a higher risk of invasive diseases caused by Listeria infections, including bloodstream infection, meningitis, and miscarriage and stillbirth. Among older adults, the risk of invasive listeriosis increases as people get older.
- The frequency of Vibriosis illness increased from 1996 to 2010, according to data from both Vibrio and FoodNet surveillance systems. More effective prevention efforts such as measures to inform the public about the hazards of raw shellfish consumption and measures to decrease contamination of oysters are recommended to decrease rates of vibriosis.
- This report summarizes FoodNet data regarding laboratory-confirmed cases of Cyclospora infection during 1997-2009. While the number of Cyclospora infections reported varied markedly from year to year, the reported cases were concentrated in time (spring and summer) and place (Connecticut and Georgia).
- This article describes antibiotic resistance patterns of Shigella samples submitted to FoodNet sites. Resistance to commonly used antibiotics is high. Although most cases of shigellosis can be managed without antibiotics, it may be more difficult to treat severe infections if Shigella isolates are becoming resistant to commonly used antibiotics.
- Infections from Salmonella serotype Enteritidis are a growing problem in the United States. Chicken and eggs are likely major sources.
- Culture-independent testing is becoming a more common way to diagnose foodborne diseases, and with it comes challenges and opportunities for public health agencies, clinical laboratories and industry. This report summarizes these challenges and opportunities, and suggests strategies that can be adopted to ensure that surveillance data continues to be accurate. Some of the strategies suggested for public health agencies include collecting information on testing methods used, regularly surveying clinical laboratories regarding testing practices, and conducting validation studies.
- This study highlights the need to develop recommendations for best practices for Campylobacter diagnostic testing. Although most laboratories are using culture-based methods to identify Campylobacter infections, procedures differ widely and most labs do not adhere to existing guidelines, likely resulting in under-diagnosis.