Laboratory tests for diagnosing Gastroenteritis/foodborne intoxication
Gastroenteritis/foodborne intoxication should be recorded using name of specific disease or toxin.  Generally the presence of the organism or toxin can be regarded as a positive result but the result may need to be interpreted in relation to symptoms, incubation times, food history etc.

Bacillus cereus food intoxication:  Isolation of ≥ 10³/g B. cereus from a clinical specimen or ≥ 10⁴ B. cereus from leftover food or detection of diarrhoeal toxin in a faecal sample.

Botulism:  Detection of botulinum toxin in serum, faeces or leftover food.

Chemical food poisoning:  Detection of implicated chemical in leftover food.

Ciguatera fish poisoning:  Demonstration of  ciguatoxin in implicated fish.

Clostridium perfringens food intoxication:  Detection of enterotoxin in faecal specimen or faecal spore count of ≥ 10⁶/gram or isolation of ≥ 10⁵C. perfringens in leftover food.

Histamine (scombroid) poisoning:  Detection of histamine levels ≥ 50mg/100g fish muscle.

Norovirus gastroenteritis:  Detection of NLV in faecal or vomit specimen or leftover food.

Other viral gastroenteritis:  Detection of virus in faecal or blood specimen.

Rotavirus gastroenteritis:  Detection of rotavirus antigen in faecal specimen.

Staphylococcal food intoxication: Detection of enterotoxin in faecal or vomit specimen or in leftover food or isolation of ≥ 10³/gram coagulase-positive S. aureus from faecal or vomit specimen or ≥ 10⁵ from leftover food.

Vibrio parahaemolyticus infection:  Isolation of Kanagawa-positive or pathogenic serotype of V. parahaemolyticus from a faecal specimen or isolation of ≥ 10⁵/gram V. parahaemolyticus from leftover food.

Laboratory tests for diagnosing for other Notifiable Enteric Diseases

Campylobacteriosis: Isolation of Campylobacter from a clinical specimen.

Cholera:  Isolation of Vibrio cholerae serogroup O1 or O139 from a clinical specimen.

Cryptosporidiosis:  Detection of Cryptosporidium parvum oocysts in a faecal specimen.

Giardiasis: Detection of Giardia cysts or trophozoites in a specimen from the human intestinal tract
OR detection of Giardia antigen in faeces.

Paratyphoid: Isolation of Salmonella Paratyphi from any clinical specimen.

Salmonellosis:  Isolation of Salmonella species from any clinical specimen.

Shigellosis: Isolation of Shigella from a clinical specimen.

Typhoid:  Isolation of Salmonella Typhi from any clinical specimen.

Yersiniosis: Isolation of Yersinia enterocolitica or Y. pseudotuberculosis from blood or faeces
OR detection of circulating antigen by ELISA or agglutination test.