|
Center for Food Safety & Applied Nutrition Foodborne Pathogenic Microorganisms and Natural Toxins Handbook |
|
|
1. Name of the Organism: Vibrio cholerae Serogroup Non-Ol |
This bacterium infects only humans and other primates. It is related to V. cholerae Serogroup O1, the organism that causes Asiatic or epidemic cholera, but causes a disease less severe than cholera. Both pathogenic and nonpathogenic strains of the organism are normal inhabitants of marine and estuarine environments of the United States. This organism has been referred to as non-cholera vibrio (NCV) and nonagglutinable vibrio (NAG) in the past. |
| 2. Name of Acute Disease: | Non-Ol V. cholerae gastroenteritis is the name associated with this illness. |
| 3. Nature of the Disease: | Diarrhea, abdominal cramps, and fever are the predominant symptoms associated with this illness, with vomiting and nausea occurring in approximately 25% of infected individuals. Approximately 25% of infected individuals will have blood and mucus in their stools. Diarrhea may, in some cases, be quite severe, lasting 6-7 days. Diarrhea will usually occur within 48 hours following ingestion of the organism. It is unknown how the organism causes the illness, although an enterotoxin is suspected as well as an invasive mechanism. Disease is caused when the organism attaches itself to the small intestine of infected individuals and perhaps subsequently invades.
Infective dose -- It is suspected that large numbers (more than one million) of the organism must be ingested to cause illness. |
| 4. Diagnosis of Human Illness: | Diagnosis of a V. cholerae non-Ol infection is made by culturing the organism from an individual's diarrheic stool. |
| 5. Foods in which it Occurs: | Shellfish harvested from U.S. coastal waters frequently contain V. cholerae serogroup non-Ol. Consumption of raw, improperly cooked or cooked, recontaminated shellfish may lead to infection. |
| 6. Relative Frequency of Disease: | No major outbreaks of diarrhea have been attributed to this organism. Sporadic cases occur frequently mainly along the coasts of the U.S., and are usually associated with the consumption of raw oysters during the warmer months. |
| 7. The Usual Course of Disease and Some Complications: | Diarrhea resulting from ingestion of the organism usually lasts 7 days and is self-limiting. Antibiotics such as tetracycline shorten the severity and duration of the illness. Septicemia (bacteria gaining entry into the blood stream and multiplying therein) can occur. This complication is associated with individuals with cirrhosis of the liver, or who are immunosuppressed, but this is relatively rare. FDA has warned individuals with liver disease to refrain from consuming raw or improperly cooked shellfish. |
| 8. Target Populations: | All individuals who consume raw shellfish are susceptible to diarrhea caused by this organism. Cirrhotic or immunosuppressed individuals may develop severe complications such as septicemia. |
| 9. Analysis of Foods: | Methods used to isolate this organism from foods are similar to those used with diarrheic stools. Because many food isolates are nonpathogenic, pathogenicity of all food isolates must be demonstrated. All virulence mechanisms of this group have not been elucidated; therefore, pathogenicity testing must be performed in suitable animal models. |
| 10. Selected Outbreaks: |
Sporadic cases continue to occur all
year, increasing in frequency during the warmer months.
An update report from CDC on Vibrio cholerae O139 in Asia may be found in MMWR 44(11):1995 Mar 24. See MMWR 42(26):1993 Jul 09 for a report on the new O139 Non-O1 Vibrio cholerae (Bengal). |
| For more information on recent outbreaks see the Morbidity and Mortality Weekly Reports from CDC. |
mow@cfsan.fda.gov
January 1992 with periodic updates
