FOOD BORNE DISEASES

FOOD BORNE DISEASES (INFECTIONS AND INTOXICATION)

Table 1: Bacterial Food Diseases (Infections and Intoxication)

Etiologic Agent	Incubation Period	Clinical Syndrome	Confirmation
Bacillus cereus – Vomiting toxin	1-6 hrs	Vomiting; some patients with diarrhea; fever uncommon	Isolation of organism from stool of two or more ill persons and not from stool of control patients OR Isolation of 10⁵ organisms/g from epidemiologically implicated food, provided specimen is properly handled
Bacillus cereus – Diarrheal toxin	6-24 hrs	Diarrhea, abdominal cramps, and vomiting in some patients; fever uncommon	Isolation of organism from stool of two or more ill persons and not from stool of control patients OR Isolation of 10⁵ organisms/g from epidemiologically implicated food, provided specimen is properly handled
Brucella	Several days to several mos; usually >30 days	Weakness, fever, headache, sweats, chills, arthralgia, weight loss, splenomegaly	Two or more ill persons and isolation of organism in culture of blood or bone marrow; greater than fourfold increase in standard agglutination titer (SAT) over several wks, or single SAT 1:160 in person who has compatible clinical symptoms and history of exposure
Campylobacter jejuni/coli	2-10 days; usually 2-5 days	Diarrhea (often bloody), abdominal pain, fever	Isolation of organism from clinical specimens from two or more ill persons OR Isolation of organism from epidemiologically implicated food
Clostridium botulinum	2 hrs-8 days; usually 12-48 hrs	Illness of variable severity; common symptoms are diplopia, blurred vision, and bulbar weakness; paralysis, which is usually descending and bilateral, might progress rapidly	Detection of botulinum toxin in serum, stool, gastric contents, or implicated food OR Isolation of organism from stool or intestine
Clostridium perfringens	6-24 hrs	Diarrhea, abdominal cramps; vomiting and fever uncommon	Isolation of 10⁶ organisms/g from stool of two or more ill persons, provided specimen is properly handled. OR Demonstration of enterotoxin in the stool of two or more ill persons OR Isolation of 10⁵ organisms/g from epidemiologically implicated food, provided specimen is properly handled
Escherichia coli –Enterohemorrhagic (E. coli O157:H7 and others)	1-10 days; usually 3-4 days	Diarrhea (often bloody), abdominal cramps (often severe), little or no fever	Isolation of E. coli O157:H7 or other Shiga-like toxin-producing E. coli from clinical specimen from two or more ill persons OR Isolation of E. coli O157:H7 or other Shiga-like toxin-producing E. coli from epidemiologically implicated food
Escherichia coli –Enterotoxigenic (ETEC)	6-48 hrs	Diarrhea, abdominal cramps, nausea; vomiting and fever less common	Isolation of organism of same serotype, demonstrated to produce heat-stable (ST) and/or heat-labile (LT) enterotoxin, from stool of two or more ill persons
Escherichia coli –Enteropathogenic (EPEC)	Variable	Diarrhea, fever, abdominal cramps	Isolation of organism of same enteropathogenic serotype from stool of two or more ill persons
Escherichia coli –Enteroinvasive (EIEC)	Variable	Diarrhea (might be bloody), fever, abdominal cramps	Isolation of same enteroinvasive serotype from stool of two or more ill persons
Listeria monocytogenes –Invasive disease	2-6 wks	Meningitis, neonatal sepsis, fever	Isolation of organism from normally sterile site
Listeria monocytogenes –Diarrheal disease	Unknown	Diarrhea, abdominal cramps, fever	Isolation of organism of same serotype from stool of two or more ill persons exposed to food that is epidemiologically implicated or from which organism of same serotype has been isolated
Nontyphoidal Salmonella	6 hrs-10 days; usually 6-48 hrs	Diarrhea, often with fever and abdominal cramps	Isolation of organism of same serotype from clinical specimens from two or more ill persons OR Isolation of organism from epidemiologically implicated food
Salmonella Typhi	3-60 days; usually 7-14 days	Fever, anorexia, malaise, headache, and myalgia; sometimes diarrhea or constipation	Isolation of organism from clinical specimens from two or more ill persons OR Isolation of organism from epidemiologically implicated food
Shigella spp.	12 hrs-6 days; usually 2-4 days	Diarrhea (sometimes bloody), often accompanied by fever and abdominal cramps	Isolation of organism of same species or serotype from clinical specimens from two or more ill persons OR Isolation of organism from epidemiologically implicated food
Staphylococcus aureus	30 min-8 hrs; usually 2-4 hrs	Vomiting, diarrhea	Isolation of organism of same phage type from stool or vomitus of two or more ill persons OR Detection of enterotoxin in epidemiologically implicated food OR Isolation of 10⁵ organisms/g from epidemiologically implicated food, provided specimen is properly handled
Streptococcus, group A	1-4 days	Fever, pharyngitis, scarlet fever, upper respiratory infection	Isolation of organism of same M- or T-type from throats of two or more ill persons OR Isolation of organism of same M- or T-type from epidemiologically implicated food
Vibrio cholerae –O1 or O139	1-5 days	Watery diarrhea, often accompanied by vomiting	Isolation of toxigenic organism from stool or vomitus of two or more ill persons OR Significant rise in vibriocidal, bacterial-agglutinating, or antitoxin antibodies in acute- and early convalescent-phase sera among persons not recently immunized OR Isolation of toxigenic organism from epidemiologically implicated food
Vibrio cholerae –non-O1 and non-O139	1-5 days	Watery diarrhea	Isolation of organism of same serotype from stool of two or more ill persons
Vibrio parahaemolyticus	4-30 hrs	Diarrhea	Isolation of Kanagawa-positive organism from stool of two or more ill persons OR Isolation of 10⁵ Kanagawa-positive organisms/g from epidemiologically implicated food, provided specimen is properly handled
Yersinia enterocolitica	1-10 days; usually 4-6 days	Diarrhea, abdominal pain (often severe)	Isolation of organism from clinical specimen from two or more ill persons OR Isolation of pathogenic strain of organism from epidemiologically implicated food

Table 2: Parasitic Food Diseases (Infections and Intoxication)

Etiologic Agent	Incubation Period	Clinical Syndromes	Confirmation
Cryptosporidium spp.	2-28 days; median: 7 days	Diarrhea, nausea, vomiting; fever	Demonstration of oocysts in stool or in small-bowel biopsy of two or more ill persons OR Demonstration of organism in epidemiologically implicated food
Cyclospora cayetanensis	1-14 days; median: 7 days	Diarrhea, nausea, anorexia, weight loss, cramps, gas, fatigue, low-grade fever; may be relapsing or protracted	Demonstration of the parasite by microscopy or molecular methods in stool or in intestinal aspirate or biopsy specimens from two or more ill persons OR Demonstration of the parasite in epidemiologically implicated food
Giardia intestinalis	3-25 days; median: 7 days	Diarrhea, gas, cramps, nausea, fatigue	Demonstration of the parasite in stool or small-bowel biopsy specimen of two or more ill persons
Trichinella spp.	1-2 days for intestinal phase; 2-4 wks for systemic phase	Fever, myalgia, periorbital edema, high eosinophil count	Two or more ill persons and positive serologic test or demonstration of larvae in muscle biopsy OR Demonstration of larvae in epidemiologically implicated meat

Table 3: Viral Food Diseases (Infections and Intoxication)

Etiologic Agent	Incubation Period	Clinical Syndrome	Confirmation
Hepatitis A	15-50 days; median: 28 days	Jaundice, dark urine, fatigue, anorexia, nausea	Detection of immunoglobulin M antibody to hepatitis A virus (IgM anti-HAV) in serum from two or more persons who consumed epidemiologically implicated food
Norovirus (NoV)	12-48 hrs (median 33 hours)	Diarrhea, vomiting, nausea, abdominal cramps, low-grade fever	Detection of viral RNA in at least two bulk stool or vomitus specimens by real-time or conventional reverse transcriptase-polymerase chain reaction (RT-PCR) OR Visualization of viruses (NoV) with characteristic morphology by electron microscopy in at least two or more bulk stool or vomitus specimens OR Two or more stools positive by commercial enzyme immunoassay (EIA)
Astrovirus	12-48 hrs	Diarrhea, vomiting, nausea, abdominal cramps, low-grade fever	Detection of viral RNA in at least two bulk stool or vomitus specimens by real-time or conventional reverse transcriptase-polymerase chain reaction (RT-PCR) OR Visualization of viruses (NoV) with characteristic morphology by electron microscopy in at least two or more bulk stool or vomitus specimens OR Two or more stools positive by commercial enzyme immunoassay (EIA)

Fungal Intoxication:

· Aflatoxicosis is caused by aflatoxins produced by the fungi, e.g. Aspergillus flavus.

· Four types of aflatoxins have been described i.e. aflatoxin B₁, B₂, G₁ and G₂.

· Animals consuming feeds contaminated with aflatoxin B₁ leads to secretion in the milk of aflatoxin

M₁ and M₂

Table 4: Chemical Food Intoxication

Etiologic Agent	Incubation Period	Clinical Syndrome	Confirmation
Marine toxins – Ciguatoxin	1-48 hrs; usually 2-8 hrs	Usually gastrointestinal symptoms followed by neurologic symptoms (including paresthesia of lips, tongue, throat, or extremities) and reversal of hot and cold sensation	Demonstration of ciguatoxin in epidemiologically implicated fish OR Clinical syndrome among persons who have eaten a type of fish previously associated with ciguatera fish poisoning (e.g., snapper, grouper, or barracuda)
Marine toxins – Scombroid toxin (histamine)	1 min-3 hrs; usually 1 hr	Flushing, dizziness, burning of mouth and throat, headache, gastrointestinal symptoms, urticaria, and generalized pruritis	Demonstration of histamine in epidemiologically implicated fish OR Clinical syndrome among persons who have eaten a type of fish previously associated with histamine fish poisoning (e.g., mahi-mahi or fish of order Scomboidei)
Marine toxins – Paralytic or neurotoxic shellfish poison	30 min-3 hrs	Paresthesia of lips, mouth or face, and extremities; intestinal symptoms or weakness, including respiratory difficulty	Detection of toxin in epidemiologically implicated food OR Detection of large numbers of shellfish-poisoning-associated species of dinoflagellates in water from which epidemiologically implicated mollusks are gathered
Marine toxins – Puffer fish, tetrodotoxin	10 min-3 hrs; usually 10-45 min	Paresthesia of lips, tongue, face, or extremities, often following numbness; loss of proprioception or floating sensations	Demonstration of tetrodotoxin in epidemiologically implicated fish OR Clinical syndrome among persons who have eaten puffer fish
Heavy metals (Antimony, Cadmium, Copper, Iron, Tin, Zinc)	5 min-8 hrs; usually <1 hr="" o:p="">