Aeromonas hydrophila diarrhea in a long-term care setting

Infectious diarrheal diseases can be a serious problem in long-term care institutions. Aeromonas hydrophila, a facultative, anaerobic gram-negative rod, has not been implicated previously in an acute diarrheal outbreak in this setting. We report 17 patients with this disorder all characterized by the acute onset of painless, nonbloody diarrhea. Thirteen of 17 (76%) patients had two to four loose bowel movements and a duration of illness of less than 48 hours. Eleven of 17 (65%) patients were afebrile. Stool cultures were obtained in 11 patients; 4 (36%) were positive for A. hydrophila. The disease was fatal in one patient who experienced profuse diarrhea and developed fever, tachycardia, and hypotension. The original source of the A. hydrophila was not identified but transmission is known to be water- or food-borne. Although usually mild and self-limited, A. hydrophila infection as noted in one patient can be fulminant and severe. A. hydrophila diarrhea responds to antibiotic therapy; it is important to consider in the differential diagnosis of acute diarrheal illness among older persons in an institutional setting.