Hi D.,
With Listeria, what matters is whether the milk used in soft cheese (technically, cheese aged for fewer than 60 days)has been pasteurized. If not, there is a fear of contracting Listeria, which wouldn't be a big deal for a healthy adult but is a problem during pregnancy. These days, the majority of cheeses, even my favorite super-stinky, runny French cheese, Epoisses, are made with pasteurized milk, at least for the US market. A few years ago there was a crackdown on cheese made with unpasteurized milk and aged fewer than 60 days that was being smuggled into the US for top end restaurants and cheese shops. My beloved Epoisses was smuggled into the country in its non-pasteurized form. Even before the crackdown, though, almost all brie sold in the US used pasteurized milk. I'm not sure about feta. Certain cheeses are made both with pasteurized and non-pasteurized milk, depending on whether the batch is intended for export to the US. Definitely check w/your OB on all of this, but look for domestic soft cheeses, many of which are quite good -- especially the Red Hawk and Mt. Tam cheeses from Cowgirl Creamery. Their website says that they pasteurize their milk (I think all domestic producers have to, but don't go just off my word on that). I would probably steer clear of imported soft cheeses just in case the non-pasteurized form is still being smuggled into the country. To the extent it is, it's probably all being directed to super high end restaurants and cheese purveyors. You're unlikely to find it at a typical grocery store, and it's unlikely to be brie (though why take a chance?). Also, just because a cheese is made with unpasteurized cheese, it does not mean that the cheese carries Listeria, just that it might; so, if by any chance you are actually pregnant and you did eat some feta or brie, you're likely just fine.
K.