Pathogenicity:V. cholerae is the causative agent of cholera. It grows in the small intestine and produces an exotoxin (choleragen) that leads to sudden loss of fluids and electrolytes leading to shock, collapse and often death. Characterized by a profuse (up to 20 liters a day!) and watery diarrhea called rice water stools. An epidemic in 1991-1992 in S. America resulted in over 700,000 cases and 6,000 deaths. Transmitted via contaminated water - fecal-oral route. There is a vaccine available for people who work and live in endemic areas such as Asia and India.
V. parahaemolyticus causes a less severe form of gastroenteritis. The organism usually inhabits coastal salt water and transmission is via raw or undercooked shellfish. It has a generation time of only ten minutes! It is the most common cause of gastroenteritis in Japan. Thousands of cases are reported annually. Fortunately, the symptoms only last about a day or so.
Treatment: fluid and electrolyte replacement with tetracycline.
