Hi!
The concern about sandboxes is probably that there could be cat feces in the sand, and that could contain the toxo spores. I must admit that in my 20 years of practice I have never seen a single case of toxoplasmosis! I"m pretty sure most other OBs would say the same. What I am trying to convey is that if you use good handwashing techniques, avoid cat boxes, avoid sick kids, etc. you should be just fine. If you want to know, you could ask your OB to check your titres--you may already be immune.
Hope this helps!
Dr B
Get the titers done, but most adults have already built up an immunity