Warwick wrote:

snips......
I wish people would get themselves straight on this one.

The old wives' tale that once a woman is pregnant she must banish all
cats from her household is simply not true.

possibly .....

T.Gondii infects the vast majority of cats while they are kittens. An
adult cat has thrown out the parasite unless it it immunosuppressed in
some way (cat HIV). The risks to the mother are highest during the first
trimester.

If you say so, although the article in New Scientist some months ago did
not mention that adult cats were immune and I haven't seen that claimed
anywhere else.

As a precaution pregnant women are advised to avoid all fecal matter
from cats throughout pregnancy. To increase the risk by being accurate
you should say that pregnant women should avoid ingesting fecal matter
of kittens and sick cats for the first half of pregnancy.

Including adult cats? And how much fecal matter needs to be ingested?

Flies, beetles and cockroaches are common carriers of T.Gondii and their
fecal matter can harbour live eggs. The fly and beetle matter is much
more likely to be present in the soil when gardning and a T.Gondii
infection from such a source is overwhelmingly likely to be the source
of an accidental gardening infection (presumably you don't know you've
had your hand on a speck of fly crap and are more likely to e.g. get
that small splinter out with your teeth than if the splinter came after
you'd encountered cat faeces).

Hmm .... If a speck of insect fecal matter is a risk, then touching cats
strikes me as a serious problem. Have you watched what cats lick?

A pregnant woman should be gardning in gloves especially for the first
half of the pregnancy since there's lots of nasties in the soil and
T.Gondii is just one of them.

Warwick

What else is a specific threat to pregnant women? Most of the threats in
soil are a general threat to everybody, aren't they? Isn't it only T.
gondii which is a specific threat to pregnant women?

My understanding is that T. gondii is part of a predator/prey parasitic
cycle which changes the behaviour of the prey (small rodents) so that
the predator (cats) catches more infected prey, thus amplifying the
incidence of the parasite in the predator and prey species. And, as
usual, the predator tends to concentrate the the parasite/poison, being
at the top of the food chain (e.g. DDT and birds of prey).

So, with no evidence, other than a small appreciation of predator/prey
dynamics, my first guess would be that a top predator (cat) would
concentrate T. gondii parasites much more significantly than insects,
much lower down the food chain:-)

But I could be wrong!
--
Larry Stoter