Forensic medicine and food safety: it’s not always an intuition | JS detained

[author: Dr. Allison Stock]


You roll out of bed in the middle of the night with an upset stomach and you think “wow, I must have eaten something bad yesterday”. If you’ve done this, you’re not alone. The Centers for Disease Control and Prevention (CDC) estimate that one in six Americans suffers from some form of foodborne illness each year, or about 48 million people. Foodborne illness accounts for 128,000 hospitalizations in the United States each year.


Currently, there are two hundred and fifty (250) known disease-causing microorganisms or pathogens responsible for twenty (20) percent of reported foodborne cases. The cause of the remaining eighty (80) percent of foodborne illness cases is unknown. Additionally, physical or chemical contamination such as contamination from pesticides or debris has also been associated with the disease. In the United States, the top five pathogens that cause foodborne illness are noroviruses (58%), Salmonella (ten%), Perfringes of Clostridium (ten%), Campylobactr (9%), and Staphylococcus aureus. Salmonella infections (salmonellosis cases) are responsible for the majority of hospitalizations and most deaths from all known pathogens. There are also seasonal patterns for foodborne illnesses, norovirus infections are more likely to occur in the winter, while campylobacteriosis and salmonellosis occur more often during the summer months.

For this article, we will focus our discussion on foodborne illnesses and food contamination in the foodservice, retail, and hospitality industries. Trained experts, such as epidemiologists and toxicologists, determine how these incidents may have occurred, including the root cause, and provide recommendations on how to eliminate or fix the problem. Additionally, trained experts understand the proper testing for suspect foods and testing the sick person(s). A trained epidemiologist can also help you understand if you have a single case of illness or if there are multiple cases. For example, an epidemiologist can create an epidemiological curve, a type of graph, to determine how long illness has occurred from ingesting the suspect food in multiple people. This curve can be used to rule out other illnesses such as non-foodborne viruses that could have caused symptoms similar to foodborne illness.

Understanding Foodborne Pathogens

Foodborne pathogens can cause several types of illnesses. Salmonella and norovirus can cause illness through the consumption of live pathogens that reproduce and grow in the intestinal tract, which is called a foodborne infection. An organism like Bacillus cereus, a pathogen found in rice and grains, can cause food poisoning illness via the production of toxins (live bacteria do not need to be eaten). These microorganisms generally do not cause food to look, taste or smell bad, which can make it impossible to determine if food is contaminated.

For a pathogen to grow and proliferate, certain conditions must be met. The first condition is that the pathogen, or its toxin, must be in the food. Many raw foods have natural background levels of pathogen contamination that are permitted under US Food and Drug Administration (FDA) rules. These pathogens can thrive when temperature and nutrients are suitable for pathogen growth. Protein-rich foods such as eggs, meat, fish, and milk can provide appropriate nutrient levels for pathogens. In addition, slightly acidic foods (pH 4.6-7.6) also promote microbiological growth. Foodborne pathogens grow best in foods at temperatures between 70 and 104°F. To prevent growth, hot foods should be kept hot and cold foods should be kept cold. Common foodservice foods that pose a higher risk of foodborne illness include rice, cooked or raw animal products, cooked or raw vegetables, raw sprouted seeds, raw shell eggs, or water-cooled hard-boiled eggs, cut melons and garlic-oil mixtures. .

Once a pathogen has been allowed to grow in a food, foodborne illness can set in after the contaminated food is consumed. Most foodborne illnesses can occur within two to twenty-four (2-24) hours of eating contaminated food, but symptoms have been reported up to thirty (30) days after eating contaminated food. The timing of the onset of foodborne illness symptoms may depend on the pathogen. The most common symptom is diarrhea, but symptoms can include vomiting, cramps, fever, and flu-like symptoms.

Trained personnel, such as epidemiologists and toxicologists, understand the nuances of collecting, storing, transporting, and analyzing biological samples of food and biological samples. This staff is also important in determining which testing labs have the appropriate certifications, such as being an International Organization for Standardization (ISO) 17025 compliant lab to perform the required testing.

Prevention strategies

To avoid potential problems in food production and food service, it is very important to control or eliminate pathogens in food products. There are four major prevention strategies: people, processes, procedures and documentation.


Facility staff are a key partner in the prevention of foodborne illness. Practices such as hand-washing and prohibiting bare-handed contact with prepared foods are essential preventive measures. In addition, employees are essential to the implementation of processes, strategy number two, and procedures, strategy number three.

Processes and procedures

Standard operating procedures (SOPs) and employee training and education are other strategies for preventing foodborne illness. SOPs should address everything from where the product can be ordered, how it is received, how it is stored, how long it is stored, how it is prepared, where it is prepared, by whom it is is prepared, how it is transported, and how it is served. Comprehensive SOPs go a long way to not only preventing foodborne illnesses, but also defending claims. However, this is only if they are respected. These processes should be living documents that are regularly reviewed for changes in best practices. Additionally, these SOPs should reflect local, state, and federal food handling regulations.

Employee training should be done on an ongoing basis, especially in locations that may have seasonal workers or high staff turnover, and management teams should continually verify that SOPs are being followed. Comprehension questionnaires that employees sign, or attendance sheets, are a way to document both attendance and understanding of training materials. There are also several food handler training certifications such as those offered by ServSafe and Learn2Serve. These can be done online and provide employees with valuable training in developing safe food handling protocols. Also, check with the local municipality’s health department to determine where training records should be kept and if certain certificates should be displayed.


Document your SOPs and date any revisions to these documents. As mentioned earlier, SOPs should be a living document that is revised at least once a year. Document your training materials and employee training, especially when you have revised your SOPs. Even document things like cleaning products (list brand names) used in which places or situations. Document your emergency action plan which includes items such as who in your organization should respond when a foodborne illness claim occurs and how that employee has been trained to respond, including questions that may be posed to the applicant. Document your facility’s compliance with federal, state, and local regulations. Consider conducting a Hazard Analysis and Critical Control Point (HACCP) analysis, which can be your quality assurance and risk assessment steps. HACCP includes the development of preventive measures; assess critical control points and prevent, eliminate or reduce risks; evaluate and establish critical limits such as cooking temperatures; monitor CCPs with temperature measurements; corrective action; record keeping systems; and verification.


Foodborne illness can be a serious problem for any establishment. Understanding how pathogens are transmitted and what processes and procedures are needed to reduce transmission are the means to protect facilities from devastating loss. Implementing the four key prevention strategies will help defend a foodborne illness claim. Additionally, having trained personnel and the appropriate accredited laboratory once problems arise will also help defend against a foodborne illness claim.


We would like to thank Allison Stock, PhD, MPH, MS, for her knowledge and expertise which greatly aided this research.


Lal, A., Hales, S., French, N., & Baker, MG (2012). Seasonality in human zoonotic enteric diseases: a systematic review. Plos a, seven(4), e31883.

Gilbert, RJ, Stringer, MF and Peace, TC (1974). The survival and growth of Bacillus cereus in boiled and fried rice in relation to outbreaks of food poisoning. The Journal of Hygiene, 73(3), 433–444.

US Centers for Disease Control and Prevention. (2019). Germs and foodborne illnesses.

US Food and Drug Administration. Retail Food Protection: Employee Health and Personal Hygiene Manual.

US Food and Drug Administration. (2017). HACCP principles and application guidelines.


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