Five healthy adult community volunteers participated in a virulent cholera challenge study at the Johns Hopkins University Vaccine Testing Unit with challenge occurring on September 10. This is the fourth group tested with this challenge at the VTU and the third receiving a dose of 5 logs. The inoculum of 9.9 X 10 4 was prepared and administered. Four of five volunteers developed diarrhea during the study, and all were managed with rehydration fluids. Three of the volunteers developed a fever. Four of 5 volunteers had stools repeatedly positive for V cholerae during days 1 to 4, but the stool cultures became negative for v. cholerae within one - two days of starting tetracycline. One did not have a stool during the study so only rectal swabs were cultured and these were negative. This volunteer also developed pruritis shortly after starting tetracycline and was switched to ciprofloxacin.