However, these cases are gender-specific, found routinely in males over 50. This is because estrogen protexted against the V. vulnificus endotoxin.
Another major disease caused by Vibrio species is cholera, which occurs when V. cholerae colonizes the small intestine and releases enterotoxins. Many antibiotic medications are inneffective in treating cholera. Thanks to improved sewage and water treatment, there is a low occurrence of V. cholerae in the United States. Over 90% of the choerla cases occurring in the U.S. are the result of travel to a country where this bacterium is prevalent. Recurring infections of cholera are rare. Attempts at creating a cholera vaccine have had only limited success. Humans are the only natural host of V. cholerae.