History and exam
Key diagnostic factors
common
presence of risk factors
Key risk factors include the following: extremes of age, pregnancy, chronic disease, recent history of travel, immunocompromised state, history of contact with other people with food poisoning, consumption of undercooked meat, consumption of raw seafood, consumption of homemade canned foods, consumption of unpasteurised soft cheeses, consumption of deli meats, consumption of unpasteurised milk or juice, consumption of raw eggs, improper food handling and storage.
diarrhoea
Usually a history of acute diarrhoea (<2 weeks).
nausea and vomiting
Staphylococcus aureus, Bacillus cereus, norovirus, or rotavirus is suspected when vomiting is the major presenting symptom. Ingestion of poisonous mushrooms or heavy metals may also present with nausea and vomiting.[2]
Other diagnostic factors
common
abdominal pain
Abdominal pain is commonly severe in inflammatory processes. Painful abdominal muscle cramps suggest underlying electrolyte loss, as in severe cholera.
Yersinia enterocolitis may mimic the symptoms of appendicitis or Crohn's ileitis (right lower quadrant pain and guarding), as can trematodiasis.
bloating
Bloating for a relatively long period should raise the suspicion of giardiasis.
fever
Suggests invasive pathogen or agent causing systemic disease. Fever may result from infection outside the gastrointestinal tract or superimposed infections.
dehydration
Dehydration may be minimal early in the diarrhoeal illness, with no signs of dehydration present. Moderate dehydration is indicated by thirst, restless or irritable behaviour, decreased skin elasticity, and sunken eyes. In severe dehydration, symptoms become more severe with shock, diminished consciousness, lack of urine output, cool, moist extremities, a rapid and feeble pulse, low or undetectable blood pressure, and pale skin. Patients with severe dehydration may also experience orthostasis.
blood or mucus in stool
Indicates invasion of the intestinal or colonic mucosa. Proctitis syndrome, seen with shigellosis, is characterised by tenesmus, rectal discomfort, and frequent painful bowel movement containing blood, pus, and mucus.
uncommon
profuse rice-water stool
Suggests cholera or a similar process. This leads to large-volume watery stools in the absence of blood, pus, or severe abdominal pain. Profound dehydration may result.
reactive arthritis
Can be seen with Salmonella, Shigella, Campylobacter, and Yersinia infections.
skin manifestations
Rose spot macules on the upper abdomen may be seen in Salmonella typhi infection.
Erythema nodosum is suggestive of Yersinia infection.
Patients with Vibrio vulnificus or V alginolyticus may present with cellulitis.
ear, nose, and throat manifestations
Exudative pharyngitis is suggestive of Yersinia infection.
Patients with Vibrio vulnificus or V alginolyticus may present with otitis media.
hepatosplenomegaly
May be seen in Salmonella typhi infection.
neurological manifestations
May encompass paraesthesia, metallic taste, visual disturbances, hallucinations, confusion, respiratory depression or distress, bronchospasm, and cranial nerve palsies. Neurological symptoms may be caused by botulism, non-infectious agents (including pesticides and mushrooms), and Campylobacter jejuni (Guillain-Barre syndrome). Diplopia, reduced muscle tone, and slurred speech are associated with botulism.
hepatobiliary disease
Patients with trematodiasis can present with features of biliary colic, cholestasis, cholelithiasis, hepatic abscess, or hepatitis.[5]
pulmonary symptoms
Patients with trematodiasis can present with chronic cough, chest pain, dyspnoea, or haemoptysis.[5]
other intestinal features
Patients can present with mucosal ulceration or malnutrition.[5]
manifestations of ectopic infection
Ectopic infection from trematodiasis can include central nervous system, heart, reproductive organ, spleen, skin, or blood vessel manifestations.[5]
Risk factors
strong
older people and pregnant women
Pregnant women and those at the extremes of age are at higher risk of, and more vulnerable to, foodborne illness. They may experience a severe illness that may require hospitalisation. Increased risk results from both direct factors (e.g., ageing immune system resulting in decreased intestinal motility and immune function and increased susceptibility to systemic illness) and indirect factors (e.g., improper food preparation and handling practices that may increase the likelihood of illness).[17][18][19]
chronic disease
Some chronic diseases (e.g., diabetes and cancer) and chronic use of immunosuppressive medications (e.g., corticosteroids, anti-tumour necrosis factor therapy, and chemotherapies) are associated with increased vulnerability to opportunistic infections.[17][20][21] People with alcohol-use disorder and people with chronic liver disease (haemochromatosis or cirrhosis) are at increased risk of infections due to Vibrio vulnificus from raw shellfish.[22]
recent history of travel
May indicate specific pathogens.
immunocompromised state
Immunocompromised states (from specific conditions or related to medications) are associated with higher risk of more frequent and more severe foodborne illness.[23]
history of contact with other people with food poisoning
Friends or family may have presented with similar symptoms.
If 2 or more people have symptoms of diarrhoea, then this is considered an outbreak.
Certain pathogens are notifiable. UK Health Security Agency: notifiable diseases and causative organisms: how to report Opens in new window CDC: how to report a foodborne illness - healthcare professionals Opens in new window
consumption of undercooked meat
Associated with Salmonella, Campylobacter, Shiga toxin-producing Escherichia coli, Clostridium perfringens, and hepatitis E.[24]
consumption of raw seafood
Associated with norovirus, Vibrio species, hepatitis A, and trematoda (flukes).
consumption of homemade canned foods
Associated with Clostridium botulinum.
consumption of unpasteurised soft cheeses
Associated with Listeria,Salmonella, Campylobacter, Shiga toxin-producing E coli, and Yersinia.
consumption of deli meats
Associated with listeriosis.
consumption of unpasteurised milk or juice
Associated with Salmonella, Campylobacter, Shiga toxin-producing E coli, Yersinia, andBrucella.
consumption of raw eggs
Associated with Salmonella.
improper food handling and storage
Associated with higher risk of developing and transmitting foodborne illness. Examples include: improper refrigeration and storage (home-canning); not rinsing cutting boards and sinks before and after washing fresh produce; not keeping raw animal products separated from fresh produce in the refrigerator, or when transporting from shop to home; not using a meat thermometer to determine whether meat is cooked; not refrigerating foods promptly; putting large quantities of hot food in the refrigerator without portioning into smaller amounts; thawing frozen food on the counter; using refrigerators that are too warm (≥6°C [43°F]) for safe storage of food.[1][17][20][25][26]
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