Food Poisoning Clinical Presentation

Updated: Jun 26, 2015
  • Author: Roberto M Gamarra, MD; Chief Editor: Julian Katz, MD  more...
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Presentation

History

A detailed history, including the duration of the disease, characteristics and frequency of bowel movements, and associated abdominal and systemic symptoms, may provide a clue to the underlying cause. The presence of a common source, types of specific food, travel history, and use of antibiotics always should be investigated.

The presenting complaints, typical features and pathogenesis of various causative agents, and diagnosis and treatment information can be found in Table 1 in the Causes section.

The following are some of the salient features of food poisoning:

  • Acute diarrhea in food poisoning usually lasts less than 2 weeks. Diarrhea lasting 2-4 weeks is classified as persistent. Chronic diarrhea is defined by duration of more than 4 weeks.
  • The presence of fever suggests an invasive disease. However, sometimes fever and diarrhea may result from infection outside the GI tract, as in malaria.
  • A stool with blood or mucus indicates invasion of the intestinal or colonic mucosa.
  • When vomiting is the major presenting symptom, suspect Staphylococcus aureus, B cereus, or Norovirus. [1]
  • Reactive arthritis can be seen with Salmonella, Shigella, Campylobacter, and Yersinia infections.
  • A profuse rice-water stool suggests cholera or a similar process.
  • Abdominal pain is most severe in inflammatory processes. Painful abdominal cramps suggest underlying electrolyte loss, as in severe cholera.
  • A history of bloating should raise the suspicion of giardiasis.
  • Yersinia enterocolitis may mimic the symptoms of appendicitis.
  • Proctitis syndrome, seen with shigellosis, is characterized by frequent painful bowel movements containing blood, pus, and mucus. Tenesmus and rectal discomfort are prominent features.
  • Consumption of undercooked meat/poultry is suspicious for Salmonella, Campylobacter, Shiga toxin E coli, and C perfringens.
  • Consumption of raw seafood is suspicious for Norwalk-like virus, Vibrio organism, or hepatitis A.
  • Consumption of homemade canned foods is associated with C botulinum.
  • Consumption of unpasteurized soft cheeses is associated with Listeria, Salmonella, Campylobacter, Shiga toxin E coli, and Yersinia.
  • Consumption of deli meats notoriously is responsible for listeriosis.
  • Consumption of unpasteurized milk or juice is suspicious for Campylobacter, Salmonella, Shiga toxin E coli, and Yersinia.
  • Salmonella has been associated with consumption of raw eggs.
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Physical

The physical examination should focus on assessing the severity of dehydration and include the following evaluation:

  • A dry mouth, decreased axillary sweat, and decreased urine output indicate mild dehydration, whereas orthostasis, tachycardia, and hypotension indicate more severe volume depletion.
  • A rectal examination always should be performed to directly visualize the stool, to test occult blood, and to palpate the rectal mucosa for any lesions.
  • Rose spot macules on the upper abdomen and hepatosplenomegaly may be seen in Salmonella typhi infection.
  • Erythema nodosum and exudative pharyngitis are suggestive of Yersinia infection.
  • Patients with Vibrio vulnificus or Vibrio alginolyticus may present with cellulitis and otitis media.
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Causes

The CDC estimates that 97% of all cases of food poisoning result from improper food handling; 79% of cases result from food prepared in commercial or institutional establishments and 21% of cases result from food prepared at home. [7]

The most common causes are as follows: (1) leaving prepared food at temperatures that allow bacterial growth, (2) inadequate cooking or reheating, (3) cross-contamination, and (4) infection in food handlers. Cross-contamination may occur when raw contaminated food comes in contact with other foods, especially cooked foods, through direct contact or indirect contact on food preparation surfaces.

Bacteria are responsible for approximately 75% of the outbreaks of food poisoning and for 80% of the cases with a known cause in the United States. [5] As many as 1 in 10 Americans has diarrhea due to food-borne infection each year.

Table 1.Causes of Food Poisoning. (Open Table in a new window)

Causative Agents Source and



Clinical Features



Pathogenesis Diagnosis and



Treatment



Staphylococci Improperly stored foods with high salt or sugar content favors growth of staphylococci.



Intense vomiting and watery diarrhea start 1-4 h after ingestion and last as long as 24-48 h



Enterotoxin acts on receptors in the gut that transmit impulses to the medullary centers Symptomatic treatment
B cereus Contaminated fried rice (emetic)



Meatballs (diarrheal)



Emetic: Duration is 9 h, vomiting and cramps



Diarrheal: Lasts for 24 h



Mainly vomiting after 1-6 h and mainly diarrhea after 8-16 h after ingestion; lasts as long as 1 d



Emetic enterotoxin (short incubation and duration) - Poorly understood



Diarrheal enterotoxin (long incubation and duration) - Increasing intestinal secretion by activation of adenylate cyclase in intestinal epithelium



Symptomatic treatment
C perfringens Inadequately cooked meat, poultry, or legumes



Acute onset of abdominal cramps with diarrhea starts 8-24 h after ingestion.



Vomiting is rare. It lasts less than 1 d.



Enteritis necroticans associated with C perfringens type C in improperly cooked pork (40% mortality)



Enterotoxin produced in the gut, and food causes hypersecretion in the small intestine Culture of clostridia in food and stool



Symptomatic treatment



C botulinum Canned foods (eg, smoked fish, mushrooms, vegetables, honey)



Descending weakness and paralysis start 1-4 d after ingestion, followed by constipation.



Mortality is high



Toxin absorbed from the gut blocks the release of acetylcholine in the neuromuscular junction Toxin present in food, serum, and stool.



Respiratory support



Intravenous trivalent antitoxin from CDC



Listeria monocytogenes Raw and pasteurized milk, soft cheeses, raw vegetables, shrimp



Systemic disease associated with bacteremia



Intestinal symptoms precede systemic disease



Can seed meninges, heart valves, and other organs



Highest mortality among bacterial food poisonings



Highly motile, heat-resistant, gram-positive organism CSF or blood culture



Must treat with antibiotics if bacteremic



Enterotoxic E coli (eg, traveler's diarrhea) Contaminated water and food (eg, salad, cheese, meat)



Acute-onset watery diarrhea starts 24-48 h after ingestion



Concomitant vomiting and abdominal cramps may be present. It lasts for 1-2 d



Enterotoxin causes hypersecretion in small and large intestine via guanylate cyclase activation Supportive treatment



No antibiotics



Enterohemorrhagic E coli (eg, E coli O157:H7) Improperly cooked hamburger meat and previously spinach



Most common isolate pathogen in bloody diarrhea starts 3-4 d after ingestion



Usually progresses from watery to bloody diarrhea. It lasts for 3-8 d



May be complicated by hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura



Cytotoxin results in endothelial damage and leads to platelet aggregation and microvascular fibrin thrombi Diagnosis with stool culture



Supportive treatment



No antibiotics



Enteroinvasive E coli Contaminated imported cheese



Usually watery diarrhea (some may present with dysentery)



Enterotoxin produces secretion



Shigalike toxin facilitates invasion



Supportive treatment



No antibiotics



Enteroaggregative E coli Implicated in traveler's diarrhea in developing countries



Can cause bloody diarrhea



Bacteria clump on the cell surfaces Ciprofloxacin may shorten duration and eradicate the organism
V cholera Contaminated water and food



Large amount of nonbloody diarrhea starts 8-24 h after ingestion. It lasts for 3-5 d



Enterotoxin causes hypersecretion in small intestine



Infective dose usually is 107 -109 organisms



Positive stool culture finding



Prompt replacement of fluids and electrolytes (oral rehydration solution)



Tetracycline (or fluoroquinolones) shortens the duration of symptoms and excretion of Vibrio



V parahaemolyticus Raw and improperly cooked seafood (ie, mollusks and crustaceans)



Explosive watery diarrhea starts 8-24 h after ingestion



It lasts for 3-5 d



Enterotoxin causes hypersecretion in small intestine



Hemolytic toxin is lethal



Infective dose is usually 107 -109 organisms



Positive stool culture



Prompt replacement of fluids and electrolytes



Sensitive to tetracycline, but unclear role for antibiotics



V vulnificus Wound infection in salt water or consumption of raw oysters



Can be lethal in patients with liver disease (50% mortality)



Polysaccharide capsule



Growth correlates with availability of iron (especially transferrin saturation >70%)



Culture of characteristic bullous lesions or blood



Immediate antibiotics if suspected (eg, doxycycline and ceftriaxone)



C jejuni Domestic animals, cattle, chickens



Fecal-oral transmission in humans



Foul-smelling watery diarrhea followed by bloody diarrhea



Abdominal pain and fever also may be present; it starts 1-3 d after exposure and recovery is in 5-8 d



Uncertain about endotoxin production and invasion Culture in special media at 42°C



Erythromycin for invasive disease (fever)



Shigella Potato, egg salad, lettuce, vegetables, milk, ice cream, and water



Abrupt onset of bloody diarrhea, cramps, tenesmus, and fever starts 12-30 h after ingestion.



Usually self-limited in 3-7 d



Organisms invade epithelial cells and produce toxins



Infective dose is 102 -103 organisms



Enterotoxin-mediated diarrhea followed by invasion (dysentery/colitis)



Polymorphonuclear leukocytes (PMNs), blood, and mucus in stool



Positive stool culture



Oral rehydration is mainstay



Trimethoprim-sulfamethoxazole (TMP-SMX) or ampicillin for severe cases



No opiates



Salmonella Beef, poultry, eggs, and dairy products



Abrupt onset of moderate-to-large amount of diarrhea with low-grade fever; in some cases, bloody diarrhea



Abdominal pain and vomiting also present, beginning 6-48 h after exposure and lasts 7-12 d



Invasion but no toxin production Positive stool culture finding



Antibiotic for systemic infection



Yersinia Pets; transmission in humans by fecal-oral route or contaminated milk or ice cream



Acute abdominal pain, diarrhea, and fever (enterocolitis)



Incubation period not known Polyarthritis and erythema nodosum in children



May mimic appendicitis



Gastroenteritis and mesenteric adenitis



Direct invasion and enterotoxin



Polymorphonuclear leukocytes and blood in stool



Positive stool culture finding



No evidence that antibiotics alter the course but may be used in severe infections



Aeromonas Untreated well or spring water



Diarrhea may be bloody



May be chronic up to 42 d in the United States



Enterotoxin, hemolysin, and cytotoxin Positive stool culture



Fluoroquinolones or TMP/SMX for chronic diarrhea



Parasitic Food Poisoning Source and Clinical Features Pathogenesis Diagnosis and Treatment
E histolytica Contaminated food and water



90% asymptomatic



10% dysentery



Minority may develop liver abscesses



Invasion of the mucosa by the parasites Criterion standard is colonoscopy with biopsy



Ova and parasites may be seen in the stool but has low sensitivity



Luminal amebicides (eg, paromomycin)



Tissue amebicides (eg, metronidazole)



G lamblia Contaminated ground water



Fecal-oral transmission in humans



Mild diarrhea with nausea and abdominal cramps starts 2-3 d after ingestion; lasts for 1 wk



May become chronic



Unknown



Highest concentration in the distal duodenum and proximal jejunum



Initial diagnostic test is stool enzyme-linked immunosorbent assay



Duodenal aspiration or small bowel biopsy



Cyst in the stool



Metronidazole



Seafood/Shellfish Poisoning Source and



Clinical Features



Pathogenesis Diagnosis and



Treatment



Paralytic shellfish poisoning Temperate coastal areas



Source - Bivalve mollusks



Onset usually is 30-60 min



Initial symptoms include perioral and intraoral paresthesia



Other symptoms include paresthesia of the extremities, headache, ataxia, vertigo, cranial nerve palsies, and paralysis of respiratory muscles, resulting in respiratory arrest



Fish acquires toxin-producing dinoflagellates General observation for 4-6 h



Maintain patent airway.



Administer oxygen, and assist ventilation if necessary



For recent ingestion, charcoal 50-60 g may be helpful



Neurotoxic shellfish poisoning Coastal Florida



Source - Mollusks



Illness is milder than in paralytic shellfish poisoning



Fish acquires toxin-producing dinoflagellates Symptomatic
Ciguatera Hawaii, Florida, and Caribbean



Source - Carnivorous reef fish



Vomiting, diarrhea, and cramps start 1-6 h after ingestion and last from days to months



Diarrhea may be accompanied by a variety of neurologic symptoms including paresthesia, reversal of hot and cold sensation, vertigo, headache, and autonomic disturbances such as hypotension and bradycardia



Chronic symptoms (eg, fatigue, headache) may be aggravated by caffeine or alcohol



Fish acquires toxin-producing dinoflagellates



Toxin increases intestinal secretion by changing intracellular calcium concentration



Symptomatic



Anecdotal reports of successful treatment of neurologic symptoms with mannitol 1 g/kg IV



Tetrodotoxin poisoning Japan



Source - Puffer fish



Onset of symptoms usually is 30-40 min but may be as short as 10 min; it includes lethargy, paresthesia, emesis, ataxia, weakness, and dysphagia; ascending paralysis occurs in severe cases; mortality is high.



Neurotoxin is concentrated in the skin and viscera of puffer fish. Symptomatic
Scombroid Source - Tuna, mahi-mahi, kingfish



Allergic symptoms such as skin flush, urticaria, bronchospasm, and hypotension usually start within 15-90 min



Improper preservation of large fish results in bacterial degradation of histidine to histamine Antihistamines (diphenhydramine 25-50 mg IV)



H2 blockers (cimetidine 300 mg IV)



Severe reactions may require subcutaneous epinephrine (0.3-0.5 mL of 1:1000 solution)



Heavy Metal Poisoning Source Symptoms Treatment
Mercury Ingestion of inorganic mercuric salts Causes metallic taste, salivation, thirst, discoloration and edema of oral mucous membranes, abdominal pain, vomiting, bloody diarrhea, and acute renal failure Consult a toxicologist



Remove ingested salts by emesis and lavage, and administer activated charcoal and a cathartic



Dimercaprol is useful in acute ingestion



Lead Toxicity results from chronic repeated exposure



It is rare after single ingestion



Common symptoms include colicky abdominal pain, constipation, headache, and irritability



Diagnosis is based on lead level (>10 mcg/dL)



Other than activated charcoal and cathartic, severe toxicity should be treated with antidotes (edetate calcium disodium [EDTA] and dimercaprol).
Arsenic Ingestion of pesticide and industrial chemicals Symptoms usually appear within 1 h after ingestion but may be delayed as long as 12 h



Abdominal pain, watery diarrhea, vomiting, skeletal muscle cramps, profound dehydration, and shock may occur



Gastric lavage and activated charcoal



Dimercaprol injection 10% solution in oil (3-5 mg/kg IM q4-6h for 2 d) and oral penicillamine (100 mg/kg/d divided qid for 1 wk)



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