Several species of "Vibrio" are pathogens. Most disease-causing strains are associated with gastroenteritis, but can also infect open wounds and cause sepsis. They can be carried by numerous marine animals, such as crabs or prawns, and have been known to cause fatal infections in humans during exposure. Risk of clinical disease and death increases with certain factors, such as uncontrolled diabetes, elevated iron levels (cirrhosis, sickle cell disease, hemochromatosis), and cancer or other immunocompromised states. Pathogenic "Vibrio" species include "V. cholerae" (the causative agent of cholera), "V. parahaemolyticus", and "V. vulnificus." "V. cholerae" is generally transmitted by contaminated water. Pathogenic "Vibrio" species can cause foodborne illness (infection), usually associated with eating undercooked seafood. When ingested "Vibrio" bacteria can primarily result in watery diarrhea along with other secondary symptoms.The pathogenic features can be linked to quorum sensing, where bacteria are able to express their virulence factor via their signalling molecules.