Table 1. Pathogen-based categories of diagnostic codes used to identify gastroenteritis-associated medical encounters, supplied by the United States Armed Forces Health Surveillance Center, July 1998–June 2011.

Pathogen Category and Diagnoses	ICD-9-CM* Code(s)
Cause unspecified
Infectious colitis, enteritis, and gastroenteritis	009.0
Colitis, enteritis, and gastroenteritis of presumed infectious origin	009.1
Infectious diarrhea	009.2
Diarrhea of presumed infectious origin	009.3
Presumed noninfectious	558.1–558.9
Symptom: Diarrhea NOS	787.91
Other viral enteritis	008.64–008.69
Intestinal infection due to other organism not elsewhere classified	008.8
Rotavirus	008.61
Adenovirus	008.62
Norovirus (Norwalk)	008.63
Bacterial
Cholera	001 (all subgroups)
Typhoid/Paratyphoid	002.0–002.9
Salmonella	003.0–003.9
Shigella	004 (all subgroups)
Vibrio parahaemolyticus	005.4
Escherichia coli	008.0
Campylobacter	008.43
Yersinia	008.44
Clostridium difficile	008.45
Other/unspecified bacteria	008.1–008.5
Other bacterial food poisoning	005.0–005.9
Protozoal
Ameba	006.0–006.2; 006.9
Other protozoal	007 (all subgroups)

*International Classification of Diseases, Ninth Revision, Clinical Modification