Re-estimating Foodborne Illness Rates

The Centers for Disease Control and Prevention (CDC) announced last month that it has updated and improved its 11-year old estimates of the prevalence of foodborne illness in the United States.

According to the new statistics, each year 48 million people, or one in six Americans, contract foodborne illnesses; 128,000 Americans are hospitalized and 3,000 die as a result of unsafe foods.  CDC’s 1999 estimates included 76 million annual foodborne illness cases, 325,000 hospitalizations and 5,000 deaths from foodborne sickness.  The agency cautions that the old and new data are not comparable and that trends in foodborne illness cannot be gleaned from these data.

What might at first glance appear to be a decline in national foodborne disease rates since 1999, CDC attributes to “improvements in the quality and quantity of the data used and new methods used to estimate foodborne-disease.”  For example, CDC notes that “it is now known that most norovirus is not spread by the foodborne route, which has reduced the estimate of foodborne norovirus from 9.2 to approximately 5.5 million cases per year.” (It has been found that norovirus is spread by contaminated hands via food preparation and contaminated surfaces.)

What are the pathogens in foods that are making us sick?  The largest category (80%) of estimated illnesses in both the 1999 and current statistics is a very unsatisfying  “unknown.”  This category includes poor investigative data on known foodborne pathogens and a failure to link the agents to the food, agents not yet recognized as causing foodborne illness and agents not yet discovered.  The remaining 20% of estimated illnesses are due to 31 identified foodborne pathogens.

Within the category of cases connected to known pathogens, approximately 90% of estimated illnesses, hospitalizations and deaths were due to seven pathogens:  Salmonella, norovirus, Campylobacter, Toxoplasma, E.coli O157, Listeria and Clostridium perfringensSalmonella was the leading cause of estimated hospitalizations and deaths.  Norovirus caused nearly 60% of the estimated illnesses, but a much smaller proportion of severe illness.

It is possible to make a real dent in these statistics.  In home, recreational, health care, restaurant and other settings it is imperative to maintain a high awareness of risks from foods that are not prepared or stored properly and the methods to reduce these risks.  As always, good personal hygiene, especially hand-washing and careful environmental sanitation are basic measures for all settings.  Meticulous food preparation, storing foods at appropriate temperatures and serving methods that prevent contamination should be continuously maintained.  It is also important to recognize the symptoms of foodborne illness at an early stage to mitigate or manage them wherever possible.

Controlling pathogens on food preparation surfaces is an important measure in reducing exposure to pathogens.  Consumers can, for example, use a simple mixture of ½ tablespoon of common laundry bleach in ½ gallon of water to help disinfect kitchen preparation surfaces following cleaning.

For more information on Food Safety, please visit the Water Quality and Health Council’s Disinfect for Health website.  While there, check out the results of the Council’s Holiday Food Safety Survey.

(Barbara M. Soule, R.N. MPA, CIC, is an Infection Preventionist and a member of the Water Quality & Health Council.)