I spoke to my LFS manager the other day, and she told me that she has had four or five people come in regarding their female guppies.

A Cottony-white covering on part of their bodies, and tattered tails.  

She wanted to know if I had heard of anything out there, and what my thoughts were.  Well, I told her that yes, someone did write in that their females had what sounds like the exact same thing!!

She wanted to know if she diagnosed it right, and we both concered that it was some sort of bacterial, columnaris-type infection.
We discussed treatments, and agreed as well.

Then she told me that she's found out that three of the big fish chains, including Walmart and Petco, are having the same problem with their females.

The only thing we could think of as to why it's just the girls, is that they are usually under more stress than the males.

We were both at a loss for determining the cause, yet my thought was that possibly it came from contaminated food.

I had recently purchased some frozen brine shrimp, not Hikari, I think it was Golden Gate, or something. When I took it out of the freezer, part of the package felt "smooshie", like it wasn't completely frozen.  
I threw that part away and broke off a chunk of it that was frozen solid, and thawed it in some aquarium water.  Before I fed it to my fish, I did the, "old smell it" test.
It smelled "riper" than what I was used too, and so I threw it all away.

At first I thought that during the holidays, the freezer compartment was probably opened more often than usual, and that may have caused the problem.

So I checked all my other frozen foods, and they were all solid, without any evidence of being thawed and refrozen.  I thawed a portion of all of them, and they were all fine.

When I told her that the person that wrote in with the same problem lives in Southern California, her response was, "Scary."  

I agree, so I would be very cautious about buying any frozen foods, and female guppies for a while.

It may also be a  good time to check our own supplies.

Please, let me know if any of you find out, or hear anything else regarding this problem.

Thanks all,