Picnic Pathogens: Treating Foodborne Illness

Picnic Pathogens: Treating Foodborne Illness
Picnic Pathogens: Treating Foodborne Illness

An estimated 48 million cases of food poisoning occur annually in the United States that result in approximately 128,000 hospitalizations and 3,000 deaths.1 Foodborne illness can be caused by bacteria and viruses, parasites, mold, toxins, and contaminants, as well as allergens.2 Food poisoning can also be caused by toxic substances that naturally exist in food (eg, mushrooms), chemical toxins (eg, pesticides, melamine), and molds.

According to the Centers for Disease Control and Prevention, the top five pathogens that cause foodborne illnesses in the United States are Norovirus (58%), Salmonella, non-typhoidal (11%), Clostridium perfringens (10%), Campylobacter spp. (9%) and Staphylococcus aureus (3%).3 While most cases of food poisoning are self-limiting, serious long-term consequences are associated with certain pathogens. The table below summarizes food sources most commonly contaminated with the top 5 illness causing pathogens, the signs & symptoms, and the recommended treatment and management of foodborne illness.

Table 1.

Microorganism Food Sources Onset After Ingestion Signs & Symptoms Management
  • Raw produce
  • Contaminated drinking water
  • Uncooked foods and cooked foods that are not reheated after contact with an infected food handler
  • Shellfish from contaminated waters
12–48 hours
  • Nausea
  • Vomiting (more prevalent in children)
  • Abdominal cramps
  • Diarrhea (more prevalent in adults)
  • Fever
  • Headache
  • Usually resolves in 12–60 hours
  • Ensure adequate hydration
  • Maintain balanced diet
  • Avoid alcohol
Salmonella (nontyphoidal)
  • Eggs
  • Poultry
  • Meat
  • Unpateurized dairy products or juice
  • Cheese
  • Contaminated raw produce
6–48 hours
  • Diarrhea
  • Fever
  • Abdominal cramps
  • Vomiting
  • Usually resolves in 1-2 days
  • Rehydration with oral or IV fluids
  • Severe cases require antibiotics: third generation cephalosporins, fluoroquinolones or ampicillin (subject to susceptibility)
Clostridium perfringens
  • Meats
  • Poultry
  • Gravy
  • Dried or precooked foods
  • Food in institutional settings, where food is prepared several hours before serving
8–16 hours
  • Intense abdominal cramps
  • Watery diarrhea
  • Usually resolves in 24 hours
  • Oral rehydration
  • Severe cases may need IV fluids and electrolytes
  • Antibiotics are not recommended
Campylobacter spp. (80% by Campylobacter jejuni)
  • Raw or undercooked poultry and meat
  • Unpasteurized milk
  • Contaminated water
2–5 days
  • Diarrhea (may be bloody)
  • Cramps
  • Fever
  • Vomiting
  • Usually resolves in 2–10 days
  • Ensure adequate hydration
  • Severe symptoms may require antibiotics treatment such as macrolides or fluoroquinolones
Staphylococcus aureus
  • Food or water contaminated from environmental surface contact or respiratory droplets
1–6 hours
  • Sudden onset of severe nausea and vomiting
  • Abdominal cramps
  • Diarrhea and fever may be present
  • Usually resolves in 1-2 days
  • Rest and rehydration are recommended treatment
  • Avoid antibiotics because it does not affect staphylococcal toxin

There are several complications associated with food poisoning, dehydration being the most common. . However, some less common but serious complications that have been seen and are attributed to specific strains of bacteria include: kidney problems, arthritis, damage to the nervous system8, and anemia3. It is important to note that these complications are rare and are usually present in “at risk” populations or otherwise immunocompromised patients.8

Kidney damage occurs when a person is infected with Escherichia coli, leading to a condition called hemolytic-uremia syndrome (HUS) in which the production of toxic substances destroy red blood cells. HUS is most commonly presented in children, and is a leading cause of acute kidney failure11 since a child's immune system tends to be underdeveloped .8 HUS has a mortality rate of 3-5% but if left untreated, can become fatal. Some survivors may have permanent disabilities such as renal insufficiency and neurological deficits.3

Arthritis is closely related to food poisoning caused by Shigella or Salmonella; patients tend to experience a condition called reactive arthritis with symptoms of pain in their joints, irritation of the eyes and painful urination. Reactive arthritis may last for months or even years, soon developing into chronic arthritis if left untreated. Furthermore, those infected with Campylobacter may develop chronic arthritis.11 Reactive arthritis is an uncommon complication, occurring in about 2% of food poisoning cases.3

Damage to the nervous system can result from food poisoning caused by Campylobacter jejuni leading to an autoimmune disease called Guillain-Barre syndrome.11 This disease can affect patients of all ages but young adults and the elderly are at particular risk. Patients typically recover fully after a couple of weeks from the syndrome, but some may experience residual weakness or even suffer a relapse.12

Pernicious anemia is related to food poisoning caused by fish tapeworm which prevents the absorption of vitamin B12.This is mostly seen in “high risk” populations but is a rare complication and can be treated with medication that kills the tapeworm.3

Food poisoning can also be deadly but in the United States, it is rare in people who are otherwise healthy.8 However, death may be a potential risk for the elderly13, cancer patients 14, diabetic patients15, and other immunocompromised patients9 if the illness is left untreated.3 Approximately 3,000 cases of food poisoning-associated deaths are reported in the United States each year. Certain strains of bacterial and viral pathogens such as Salmonella, Toxoplasma, Listeria, norovirus, and Campylobacter account for 88% of those deaths. Vibrio infections caused by consumption of raw shellfish can be severe and life-threatening, resulting in death as early as two days after infected.11

Foodborne illness can range from self-limiting symptoms to life-threatening diseases or death. Good hygiene practices and safe food-handling are effective preventative steps to avoid the occurrence of food poisoning.


1. Foodborne Illnesses: What You Need to Know. U.S. Food and Drug Administration. March 16, 2013. http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm103263.htm. Accessed May 14, 2013

2. Causes of Food Poisoning. FoodSafety.gov. http://www.foodsafety.gov/poisoning/causes/index.html. Accessed May 14, 2013

3. Bad Bug Book (2nd edition) – foodborne pathogenic microorganisms and natural toxins handbook. Center for Food Safety and Applied Nutrition of the Food and Drug Administration, U.S. Department of health and Human Services. 2012 http://www.fda.gov/Food/FoodborneIllnessContaminants/CausesOfIllnessBadBugBook/ucm2006773.htm. Accessed May 15, 2013

4. Diagnosis and Treatment of Salmonella. Centers for Disease Control and Prevention. http://www.cdc.gov/salmonella/general/diagnosis.html. Accessed May 20, 2013

5. Clostridium perfringens. Food Safety. Centers for Disease Control and Prevention. http://www.cdc.gov/foodsafety/clostridium-perfingens.html#treated. Accessed May 20, 2013

6. Campylobacter. Centers for Disease Control and Prevention. http://www.cdc.gov/nczved/divisions/dfbmd/diseases/campylobacter/#treat. Accessed May 20, 2013

7. Staphylococcal Food Poisoning. Centers for Disease Control and Prevention. http://www.cdc.gov/nczved/divisions/dfbmd/diseases/staphylococcal/#treatment. Accessed May 20, 2013

8. Food poisoning. U.S. National Library of Medicine. January 10, 2011. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002618/#adam_001652.disease.symptoms. May 16, 2013

9. People at Risk. U.S. Food and Drug Administration. March, 16, 2013. http://www.fda.gov/Food/FoodborneIllnessContaminants/PeopleAtRisk/ucm312565.htm. May 16, 2013

10. Checklist of Foods to Avoid During Pregnancy. FoodSafety.gov. http://www.foodsafety.gov/poisoning/risk/pregnant/chklist_pregnancy.html. May 16, 2013

11. Long-Term Effects. FoodSafety.gov. http://www.foodsafety.gov/poisoning/effects/index.html. May 17, 2013

12. Guillain-Barre Syndrome. National Institute of Neurological Disorders and Stroke.
http://www.ninds.nih.gov/disorders/gbs/detail_gbs.htm. May 23, 2013

13. Food Safety for Older Adults. U.S. Food and Drug Administration. http://www.fda.gov/Food/FoodborneIllnessContaminants/PeopleAtRisk/ucm312705.htm. May 22, 2013

14. Food Safety for People with Cancer. U.S. Food and Drug Administration. http://www.fda.gov/Food/FoodborneIllnessContaminants/PeopleAtRisk/ucm312565.htm. May 22, 2013

15. Food Safety for People with Diabetes. U.S. Food and Drug Administration. http://www.fda.gov/Food/FoodborneIllnessContaminants/PeopleAtRisk/ucm312706.htm. May 22, 2013

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