Microbiology
gram-negative rod; includes A. caviae, A. hydrophilia, A. salmonicida, A. sobria.
Epidemiologic Risks
Freshwater exposure. It is found in warmer climates, including cases in the Caribbean. It causes bacteremia in patients with underlying medical problems. It is part of the normal flora of leeches, so infections are associated with medicinal leeches (used in reattachment of fingers and the like). Even though antibiotics are given with leech therapy, occasionally a resistant organism sneaks in (PubMed).
Syndromes
Colitis sometimes mimicking acute ulcerative colitis, necrotizing soft tissue infection after freshwater trauma, cellulitis often with bacteremia (PubMed) and the usual hodgepodge of focal infections.
In Korea and Taiwan, it is a major cause of SBP in cirrhotics (PubMed).
In drowning patients (well, those who survive drowning) it is the most common cause of pneumonia (PubMed).
Case of recurrent infection traced to well, or not so well, water. If you ask you will be surprised at the various sources from which people get their water, even in urban areas. Here in the great Pacific NW, a remarkable number of people are on well water.
Treatment
Third-generation cephalosporins, carbapenems, or quinolones anything BUT ampicillin or ticarcillin. Note the BUT. BUT BUT BUT.
For diarrhea ciprofloxacin, 750 mg once a day; or azithromycin, 500 mg once a day, both for 3 days (PubMed).
Notes
I once had a patient who had severe colitis from Aeromonas and the source was Holy Water she brought back from a Catholic shrine in S. America. True story. From this, I deduce that Louis Pasteur went to Hell. As an aside, it is possible to get a variety of infections from Holy Water. The water in shrines often has flora similar to stool.
Curious Cases
Relevant links to my Medscape blog
Last update: 05/05/18