A pathogen responsible for a growing number of diarrhoea cases

Aeromonas hydrophila is a waterborn gram negative bacterium that is ubiquitous in brackish and freshwater environments, frequently causing illness in immunocompromised individuals, very young children and older people. Transmission can be caused via contaminated water (especially in hospital environments) and ingesting infected beef and fish (especially salmon).

The bacterium can cause a rather nasty bout of diarrhoea, that can last over a couple of weeks and is mostly associated with pretty painful abdominal pain and malaise.

Over the last couple of years there has been a controversy over wether A. hydrophila is actually responsible for the symptoms, over it is just an copathogen, but recently several studies seem to show that the little critter is actually the main pathogen.

Treatment is mostly supportive, but funnily enough the disease can be exacerbated by Augmentin due to the suppression of the other residual enteric flora. If clinically necessary (i.e. the patient is dehydrated and unwell), the antibiotic of choice is Norfloxacin. There are no current incidence records for Aeromonas species, but the literature indicates a raise in local epidemics.

Better cook that fish before you eat it then...

Source: http://vm.cfsan.fda.gov/~mow/chap17.html
and a very helpful clinical microbiologist from Southern Community Labs, New Zealand