Re: pathogens in water

I would like to support what Farzan Saleem <farzan at ibm_net> said on Fri, 
24 Jan 1997:
>Being in the field of Epidemiology, the recent questions about acquiring =
>potentially dangerous pathogens via the aquarium piqued my interest so I =
>thought I would do some quick research of medical literature and see if =
>there are any significant findings. I thought others might be interested =
>in the results, so I have summarized them below:
>I found an article out of Sweden titled "Sporothricoid mycobacterial =
>infection. A case report.".  The abstract states: "A case of bilateral, =
>symmetric, sporothricoid granulomas involving the dorsa of fingers and =
>wrists is reported. The culture-proved Mycobacterium marinum skin =
>infection was acquired by a fish-fancier while clearing his aquarium =
>with bare hands. The patient suffered from chronic hand eczema. =
>Treatment with co-trimoxazole was successful. "

What Farzan is referring to is fish tuberculosis which can be contracted 
by humans. It does not affect us badly because it prefers a lower 
temperature than human core body temperature, hence the cases I have 
heard about all involve the extremities, specifically hands which we 
repeatedly put in tanks.

I have heard of no other diseases from aquaria that humans have caught 
and I have looked (not exhaustively) at some of the literature on 
zoonoses. One of our aquarium shop owners here in Brisbane is a 
vererinarian with a PhD in fish diseases. I have asked him about the 
subject and fish tuberculosis is the only disease he knows of that can be 
transmitted from fish to humans.

That still leaves the field a little open, but I'm happy to accept 
Farzan's search of the literature which sounds a lot more exhaustive than 
what I did (I looked at textbooks but he is searching the professional 
journals for case studies). If he hasn't found anything, and he works in 
epidemiology, I'm prepared to accept that the reports just aren't there.

By the sheer nature of scientific proof, you just can't prove that 
something doesn't exist. No-one can conclusively prove you can't catch 
something from your tank but then, by the same ruled, I can't prove I 
don't have an invisible, 6 foot long white pointer shark swimming in my 3 
foot, freshwater (pH 6.8, GH = 3 degrees) planted tank. There may be 
slightly (g) more chance of me catching a disease when cleaning my tank 
than having my hand ripped off by the invisible white pointer shark, but 
not much.

I stand by what I said previously about legionella infections, but I 
forgot one other point which provides another safety factor in our tanks. 
Legionella bacteria are supposed to prefer stagnant water and we like it 
circulating - another factor that should keep their growth down.

I genuinely see no reason to worry.

David Aiken

   David Aiken                                     email: 
d.aiken at eis_net.au