Health Alert - Lake Swimmers beware

Incidence rate of rare and fatal brain infection from amoebas in lake water is increasing.

http://www.cnn.com/2007/HEALTH/10/04/amoeba.lake/index.html

PS: the article erroneously calls it a "virus". As we all know from high school biology, an amoeba is a single celled microscopic animal that lives in water.(This message has been edited by scoutldr)

Is that air temp over 80 or water temp over 80?

Sounds a cold lake is better?

Water temp.

It sounds like Lake Wobegon is safe.

One of the fatalities was from a sports camp in Texas where my son worked this summer - swimming in Lake LBJ - water temp was high, they didn''t have the issue of drought/low water which was mentioned as a factor on the news last night (they had floods much of the summer).

Boy had a non-specific symptoms - fever (not extremely high), headache, achy. Camp sent him home I think day after symptoms, family doctor put him in the hospital, died about 10 days later (after camp ended).

The only thing I''ve heard is to try to prevent water up the nose - the amoeba goes up the olifactory nerve to the brain. The news story suggested nose clips, and stories I read suggested not jumping into the water (where water is forced up nose.)

This is one of my favorites of all time and I have posted on this before. These organisms and several others like it are everywhere and they are always present in natural environments.

Scoutldr has it right in that it is what we used to think of as a microscopic animal. However, it is now listed in the kindom: Protista or Protoctista, depending on whose phylogeny you want to follow.

It is a eukaryotic, single-celled organism and mtm25653 has it correct in that the infection usually occurs through the nasal passage crossing mucous membranes and getting into the central nervous system whereupon it goes to the brain and starts eating brain cells.

Most often the infection occurs associated with swimming or some other water-related activity but there is at least one documented case where a woman died from an infection by airborne spores from her dusty, recently-tilled garden.

There was also an episode on "House" in which one patient died and the black doctor (whose name I forget just now) also gets infected. That's where the TV show leaves reality behind. They give the black doctor some drugs and he recovers.

In reality, this organism is almost 100% fatal and it is a really, REALLY, grisly death. You start with 'cold-like' symptoms, then you start to experience hallucinations or start displaying weird behaviors and mood swings. Then you really start to lose it, maybe becoming violent or maybe chewing off your own tongue or something. Then, strapped down on a hospital bed, you scream in complete dementia for a few hours or days, later becoming unconscious, then death. We don't know if patients actually experience pain or not.

It would be an interesting experience but the last one in life.

OGE is also correct in that while it is present almost everywhere all the time, it takes on the parasitic form mostly in warm or hot waters. One of the classic places this thing is found in virulent form is hot springs or really warm lakes (such as in Texas, or other southern climes). Some people were killed in New Zealand, I think, swimming in pools fed by hot springs.

When Ronald Reagan decided that this country needed to be able to bounce the rubble more often than the Soviet Union, we built a new production reactor (L-reactor) and a lake to cool it (L-Pond) at Savannah River Site. This lake was really hot, thermally, and one of the interesting things about it was that it was heavily infested with Naegleria fowleri, the parasitic amoeba. Doing work on that lake was so dangerous because of this organism that we were required to wear respirators and white suits.

I did some work on this thing a few years ago and maybe with global warming, I should take it up again. Like I said, it's one of my favorite little aquatic nasties.

Incidentally, despite what you may read, there is no way to avoid it. There is no precaution that you can take that will prevent it, should you go swimming. If you get it you are going to take the celestial dirt bath.

You are totally at the mercy of your immune system and whether or not these things have tipped over to the dark side for that lake. I really love this stuff. Have a nice day. (This message has been edited by packsaddle)

I wasn''t aware that amoebae formed spores and could survive dessiccation.

Scoutldr,

There are many aquatic organisms capable of producing forms (spores) that are resistant to adverse conditions, including dessication. They include algae, fungi, bacteria, and many protozoans including free-living amoeba.

BTW, I checked the literature and recent papers have discredited the circumstantial evidence for airborne transmission. The current wisdom is that infections are strictly waterborne.

There is some hope if the infection is diagnosed very early. The problem is that anything that attacks one eukaryotic cell (the amoeba) is likely to be kind of rough on its eukaryotic host (us). And early diagnosis is unlikely. At any rate, permanent damage and impairment is likely for survivors.

At one time there was a common wisdom that blowing one's nose would help prevent infection. I suppose it gave a sense of security or something. But for now, in reality we must swim at our own risk.

Edited part: double quote fix(This message has been edited by packsaddle)