Nah, no effects, don't worry about it. I have worked with it a lot... it's a disease that just finds me, somehow. The first time, I contacted a doctor because I wanted to catch up with a pregnant friend, and had been in contact with 9 children who had confirmed cases and another 3 who were suspected. Was told not to worry.
This pregnancy, two kids got it when I was 11 weeks. I kept pretty well clear of them, but had still been in very close contact before their spots showed up. Told my doc, who is incredibly thorough. She contacted infctious diseases at the hospy, and they said it's not a big deal at all, has no known effects.

Wash your hands, a lot. Wash every single toy that goes anywhere near his mouth or hands in warm soapy water OR (and I usually hate it, but in this instance it's great) wipe anything over with Milton solution. Same with the nappy change area, clean that thoroughly after every change.