[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

TB in fresh water tanks

>This is not to say I think one should have a cavalier attitude when it comes 
>to hygiene and aquariums, but by coincidence I had to have a tuberculin test 
>done last week and it came out negative. I've keep fish since I was a kid 
>and have alway done the no-no by starting the syphon by mouth. I may just 
>be very lucky or piscine TB is not the same as human, especially if it 
>manifests as a red rash. I made a note of the posting from the Shedd 
>Aquarium the other day. Could it be possible that the people who tested 
>positive for TB picked in up elsewhere?

There may be other nasties you can get from sucking aquarium water... (I
have heard of fish coming into wholesalers infected with E. cola, for
instance, which I would _not_ want in my mouth!<g>)  But as far as "fish
TB" is concerned, you won't get it by swallowing it.  Fish TB is _not_ a
virus as someone mused earlier in this thread, it is a bacterium.
Mycobacterium marinum to be exact.  The reason that it is of lesser concern
for people is that it cannot survive the core body temperature of a mammal.
 So you _can't_ get it as a systemic infection the way you can the
mammalian versions of TB.  

But that's also why it CAN cause localized infections on the hands and arms
of aquarists who work in an infected tank with open wounds on their hands.
The bacteria can set up housekeeping in the cooler temperatures of our
These can be in the form of open boils, or lumps or bumps under the skin,
and often start to grow in a line up the arm.  In some cases the lymph
nodes in that arm get involved.  

The obnoxious part is that, like other Mycobacteria, it is _very_ resistant
to antibiotics, so you have to be treated for a long, long time.  And being
on long-term antibiotics can cause other health problems, some merely
uncomfortable, others more severe.  Both of my friends who have had and
been treated for M. marinum had to be on antibiotics for over 9 months.

I don't keep neons, and never have, so although I've heard of NTD, I don't
know that much about it.  But if it does not slowly spread to the other
species in the tank, I doubt it is TB.  Rainbows are COMMON carriers of TB,
but as far as I know, no fish are immune.  But I also don't think that it
is so common that you'd find it in every tank, or even most tanks.  Even
among fish that have it, it tends to spread slowly, and most often that
spread is by fish eating the flesh of an infected fish that as died or
become too weak to escape.  You can even get a "clean" population of
Rainbows, by spawning the parents, pulling the eggs and raising the fry in
clean tanks.  

I work in my tanks all the time with bare arms, and have never had a
problem.  But I have a healthy population of fish, don't introduce new ones
often, and would be reluctant to put a hand with a cut into a tank that had
fish with obvious signs of the disease.  From what I've read, there is
little risk even in a tank KNOWN to harbor fish TB if you wash thoroughly
with soap and water as soon as you finish working in the tank.  That's
probably just good hygiene.

As far as I know, there is no effective cure for a fish that is infected
with TB, and the best answer is to euthanize it before the disease is
spread to other fish.