Vibrio cholerae is a species of bacteria. Some strains of Vibrio cholerae cause cholera, a severe diarrheal illness. Vibrio cholerae has many different types or serogroups, only two of which can cause epidemic cholera. Those two serogroups are called serogroup O1 and serogroup O139 (O139 is found only in Asia) and can cause epidemic cholera if they also produce the cholera toxin. The other serogroups are known collectively as non-O1 and non-O139 Vibrio cholerae. These serogroups can cause a diarrheal disease which is less severe than cholera and does not have epidemic potential.
Non-O1 and non-O139 Vibrio cholerae are the third most commonly reported group of Vibrio bacteria. On the average, around 40 cases of non-O1 and non-O139 Vibrio cholerae were reported to the CDC each year since 2000. Infections are seasonal with a peak in the late summer and early fall, coinciding with the warmest water temperatures.
Symptoms of Infection
- People with gastroenteritis caused by non-O1, non-O139 Vibrio cholerae can have symptoms of differing severity ranging from mild diarrhea to severe watery diarrhea. Fever and bloody diarrhea are not typically seen in gastroenteritis due to non-O1, non-O139 Vibrio cholerae infection.
- Sepsis due to non-O1 and non-O139 Vibrio cholerae is seen in immunocompromised people and in people with liver disease. Its symptoms include fevers, chills, and decreased blood pressure (shock).
- Non-O1 and non-0139 Vibrio cholerae has occasionally been reported to cause wound infections with redness and swelling at the site of infection.
How People Become Infected
The non-O1 and non-O139 Vibrio cholerae bacteria have a natural reservoir in sea and coastal waters. In the US, transmission of Vibrio infections is primarily through consumption of raw or undercooked seafood, particularly oysters. Casual contact with an infected person is not a risk for becoming ill. Occasionally, wounds exposed to water containing Vibrio cholerae may become infected.
Persons with profuse watery diarrhea should see a health care provider. If the health care provider suspects that the diarrheal illness is due to a Vibrio bacteria, he or she may request a stool sample for culture. The laboratory will then be able to determine if Vibrio cholerae is present and the serogroup to which it belongs.
Diarrhea caused by Vibrio cholerae is treatable, primarily by rehydration, and antibiotic therapy. The most important treatment is to replace the fluids and electrolytes that have been lost due to diarrhea. This is done either through oral fluid rehydration or, in severe cases, intravenous fluid rehydration. In many cases, antibiotics are used to hasten the recovery, but they do not take the place of early and appropriate rehydration therapy. Wounds exposed to seawater should be washed with soap and water as soon as possible, and infected wounds should be evaluated by a health care provider. Wounds that become infected and sepsis should be treated with antibiotics.
Infections with non-O1 and non-O139 Vibrio cholerae are acute illnesses, and those who recover should not expect long-term consequences.
At this time no vaccine exists for infections with non-O1 and non-O139 Vibrio cholerae.