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Foodborne illnesses in the United States are quite common. According to the Centers for Disease Control and Prevention (CDC), foodborne microorganisms cause 76 million illnesses, 325,000 hospitalizations and over 5,000 deaths each year.
Some of the most common causes of foodborne illness include microorganisms, marine organisms, fungi and chemical contaminants. An incubation period ensues from the time the organisms or contaminants enter the body until the first signs or symptoms appear. Incubation may last hours or days, depending on each patient's immune response. Usually, the more contaminated food that is swallowed, the faster a person will become ill. While digesting, the contaminated microbes may stay in the intestines, produce toxins absorbed into the bloodstream or invade the body tissues, depending on the microbe. With contaminated microbes in the body, the patient will begin to exhibit physical symptoms like diarrhea, abdominal cramps and nausea. Because of the similarity and common symptoms, specific microbes are seldom identified as causing foodborne illnesses; however, during a known outbreak, when a particular area experiences a sudden increase in the incidence of a specific disease, the microbes may be identified.
WHO'S AT RISK?
Ninety-two-year-old John is homebound. You and your partner respond to John's home, where his daughter has found him with severe abdominal cramping. When you arrive, you notice dishes stacked on the counter and in the sink, along with open containers of food covering the counters and kitchen table. John reports that he has experienced diarrhea and vomiting and has not been able to keep food or liquids down for the last two days. Your assessment shows that John has a fever of 102°F, is dehydrated and needs transport.
Elderly adults are not only more at risk for foodborne illness, but once infected, it may take them longer to recover. As the body ages, the ability to fight unwanted types of bacteria diminishes, due to a decrease in stomach acid secretion. In addition to the body's inability to rid itself of unwanted bacteria, the elderly often have a diminished sense of taste and smell. Medications, illnesses and age all contribute to the desensitization of smell and taste. While healthy younger adults may be able to smell or taste rotten food, seniors may not sense that their milk is spoiling or the chicken is bad. There are also sociological risk factors. Elders often rely on others to provide their food, and, if it becomes spoiled or rotten, they have no other option than to eat the contaminated food.
Individuals who are infected with AIDS are more prone to infections from foodborne illnesses because of compromised immune systems.1 According to the U.S. Department of Agriculture (USDA), those infected with AIDS are 100 times more frequently affected by Salmonella—the bacteria found on raw or undercooked meats and eggs—than other healthy adults. If someone with AIDS becomes infected with Salmonella, the virus can cause a more severe illness, such as pneumonia, or lead to additional complications, including death.
Pregnant women undergo major hormonal changes that lead to more susceptibility to foodborne illnesses for both the mother and unborn child. Additionally, newborns are at risk for foodborne illnesses because of underdeveloped immune systems. Salmonella can be passed to bottle-fed infants through unclean bottles.2
Listeriosis is the most serious foodborne illness to infect women during pregnancy. The CDC estimates that 2,500 people become seriously ill with listeriosis each year, and pregnant women are 20 times more likely to be infected than other healthy adults.3 The CDC further reports that about one-third of listeriosis cases occur during pregnancy, and one in five infected with listeriosis die from the infection.3 Both the mother and fetus can be infected by the illness, even when the mother is not showing symptoms. The mother passes the infection to her fetus through the placenta, which can lead to miscarriage, premature delivery, stillbirth or serious health problems for the newborn.3 Listeriosis is prevalent in certain foods, such as hot dogs; lunch meats; processed meats; soft cheeses such as brie, feta and blue cheese; refrigerated pate or meat spreads; refrigerated smoked seafood; and unpasteurized milk.
USUAL SUSPECTS
Common culprits have been tracked and researched by the American Medical Association, as well as governmental agencies. Raw meats, poultry, eggs and shellfish that come in contact with multiple animal products are particularly dangerous. Any animals infected with a foodborne illness may pass it on through human consumption. For example, a single hamburger may contain meat from literally hundreds of animals, just as one glass of milk may come from hundreds of cows.2 Raw fruits and vegetables can be hazardous if processed in unsanitary conditions. Unclean water and manure used for fertilization can contaminate hundreds of crates of fruits and vegetables. Washing them reduces the chance for foodborne illness, but doesn't eliminate it.2
SIGNS AND SYMPTOMS
The symptoms of foodborne illness vary with each patient.4 Typical symptoms may include:
Abdominal pain and cramping
Appendicitis-like presentation
Cranial nerve palsies
Dehydration
Diarrhea with or without blood
Fever
Lymphadenopathy
Motor weakness
Myalgias
Nausea
Neck stiffness and meningeal signs
Oliguria
Paresthesias
Visual disturbances
Vomiting.
FOODBORNE ILLNESS AGENTS
Any of the above symptoms can be indicative of foodborne illness. Just as the symptoms and causes may vary, so can the foodborne agent responsible for illness.
There are four types of foodborne agents:
- Bacterial
- Viral
- Parasitic
- Noninfectious.
Botulism
Botulism, a bacterial infection, can be fatal for infants and adults. Botulism is sometimes associated with infants who have consumed honey, which can contain spores of Clostridium botulinum even after processing; however, according to recent research, only 15% of infant botulism cases can be attributed to honey. The remaining 85% have unknown causes. Botulism spores are widespread but are not seen in fresh foods. Most botulism comes from home-canned foods produced in an anaerobic environment (without oxygen), where the contaminated spores can reproduce.
Gastrointestinal symptoms usually occur 18–36 hours after ingestion of infected food.5 Emergency response personnel should suspect botulism in patients with autonomic dysfunction such as dry mouth and blurred vision, cranial nerve involvement and muscle weakness. Respiratory muscle weakness advances quickly, often impairing the gag reflex and leading to possible aspiration. Immediately transport any patient suspected of having botulism, as it is fatal when left untreated.
E.coli
Another bacterial foodborne infection is E.coli, which causes more than 100,000 illnesses every year in the United States.
E.coli strains live in the intestines of healthy cattle and lead to meat contamination during slaughter. Other documented causes of E.coli come from swimming, bathing or drinking water that is contaminated with sewage. Sprouts, lettuce, salami, unpasteurized milk and unpasteurized fruit juices are also known sources of infection. E.coli symptoms occur 2–5 days after infection, beginning most often with abdominal cramping and diarrhea. In young children and the elderly, E.coli infection may lead to hemolytic uremic syndrome, which causes the destruction of red blood cells and possible kidney failure.6
E.coli patients without hemolytic uremic syndrome should receive supportive treatment of critical systems. Ensure that the patient is not dehydrated and monitor electrolyte balance. In those who are not infected with hemolytic uremic syndrome and are otherwise healthy, E.coli resolves after five to 10 days.6
Salmonella
Salmonella is another bacterium that is most often associated with raw foods. According to the Partnership for Food Safety and Education, raw meats, eggs, dairy products, frog legs and poultry are the most suspected foods leading to Salmonella. About 8–12 hours after ingestion, patients suffer abdominal pains and diarrhea. They may also have nausea and vomiting, with symptoms lasting 24 hours or less in healthy adults. Treat your patient with supportive care, monitoring for hydration and electrolyte balance.
Norwalk Virus
The most common viral infection is caused by the calicivirus, also known as Norwalk-like virus or norovirus. One outbreak occurred during the summer of 2006 when more than 100 travelers and workers aboard the Royal Caribbean Mariner of the Sea cruise ship were diagnosed with the Norwalk virus. It is generally spread from one infected person to another after consuming food or water that has been in contact with raw sewage.2 The Norwalk virus causes gastrointestinal symptoms 24 hours after infection, with more vomiting than diarrhea, and is usually resolved within 48 hours. Treat patients with oral rehydration and rest. Most healthy patients infected with the Norwalk virus do not require transport or inpatient treatment; however, those at risk may require further care.
Giardia
Other diseases are occasionally foodborne, but are most often transmitted through other routes. Giardia lamblia causes Giardia through ingestion of infective cysts, with transmission routes including: person-to-person contact, ingestion of contaminated water, or direct fecal-to-oral transmission. High incidences of Giardia in the U.S. have been documented at day-care centers and on Native American reservations with contaminated water sources. Giardia produces gastrointestinal symptoms that range from mushy stools to explosive diarrhea. Other symptoms include abdominal pain, cramping, nausea, bloating and substernal burning. Symptoms are exacerbated when patients continue eating. Weight loss is very common with Giardia, with 50% of patients losing an average of 10 lbs.8 Otherwise healthy patients generally require no hospital care for Giardia, except in cases of severe dehydration. Emergency response personnel may need to administer intravenous crystalloid fluids for severely dehydrated patients.
Staphylococcus aureus
Staphylococcus aureus grows on unrefrigerated meats, dairy and bakery products and causes intense nausea, vomiting, abdominal pain and diarrhea one to eight hours after ingestion.9 Improper handling, storage and preparation of food can cause multiple members of the same family to become infected. Treatment for patients infected with Staphylococcus aureus is generally supportive. Assess patients for dehydration, and treat as needed.
Finally, patients may be infected with foodborne illnesses from other toxins and poisonous chemicals, such as pesticides, or inadvertently eating poisonous foods. Pesticides may be intentionally or unintentionally sprayed on plants during growth to eliminate pests and bugs, and the harmful pesticides can make humans ill. Whether bacterial, viral, parasitic or noninfectious, foodborne illnesses cause uncomfortable and possibly harmful gastrointestinal symptoms.
PATIENT ASSESSMENT
Your 11-year-old patient has vomited multiple times in the last hour. She also has diarrhea and complains of stomach cramps. Her mother tells you that the girl and her friends just returned from an amusement park, and it is probably "something she ate." Upon questioning, your patient says she ate a pork sandwich at the park, as well as cotton candy, two large bottles of soda, some nachos, and a candy bar on the way home. You wonder if it's foodborne illness, a bad case of indigestion or your partner's dream day of eating.
Maintain a high index of suspicion for foodborne illness when responding to complaints of abdominal pain. Most cases present with symptoms of nausea, vomiting and diarrhea. "It must have been something I ate" is a common complaint. Such symptoms and comments should prompt you to initiate a thorough SAMPLE history, being especially attuned to what the patient has eaten and where.
TREATMENT
Monitor and maintain critical body systems. Vomiting, diarrhea and nausea could be indicative of foodborne illness, as well as many other infections and complications. Ascertain as much history as possible from your patient. Provide symptomatic treatment to relieve pain, nausea and vomiting. Other treatment in the field will depend on type of pain, pain severity, additional symptoms, exam findings and transport time. Wash your hands before patient contact and after glove removal. Follow local protocols for administration of anti-emetics, narcotic and non-narcotic pain medications. Administer IV fluids if the patient has signs and symptoms of hypovolemia.
REPORTING
Report any suspected foodborne illness to your local health department or community syndrome surveillance system. Multiple reports to these agencies can prevent further spread of foodborne illness. For example, if multiple patients with Salmonella report that they have eaten at a local pizza place in the last 24 hours, the health department can initiate an investigation of the restaurant. In more extreme circumstances, both the local health department and government agencies will take responsibility for inspecting and ruling out the possibility of bioterrorism.
SUMMARY
While nausea, vomiting and diarrhea are the most common symptoms of foodborne illness, other more serious and life-threatening conditions can occur. Foodborne illness agents can be bacterial, viral, parasitic or noninfectious. Take a thorough history when treating suspected foodborne illness to prevent further spread. Report foodborne illness through surveillance protocols in order for authorities to determine if multiple cases constitute an outbreak.
References
1. Food Safety for Persons with AIDS. www.fsis.usda.gov/fact_sheets/Food_Safety_for_Persons_with_AIDS/index.asp.
2. Foodborne Illness. www.cdc.gov/ncidod/dbmd/diseaseinfo/foodborneinfections_g.htm#morelikely.
3. Listeriosis and Pregnancy: What is Your Risk? www.fsis.usda.gov/fact_sheets/Listeriosis_and_Pregnancy_What_is_Your_Risk/index.asp.
4. Food Poisoning. www.emedicine.com/ped/topic795.htm#target1.
5. Frattarelli D. Botulism. www.emedicine.com/PED/topic273.htm#section