Hi-
OUr daughter was positive for Hep C antibodies as well. When we got to the orphanage we found out that they had actually retested her several times and found her to be negative - otherwise she could would have been in a special orphanage.
Most of what I had read is that if positive for antibodies at birth usually only 5-9% actually develop the disease and that it can take up to 18months for the antibodies to clear the bloodstream.
Here is a good link about Hep C - I have a ton of others - pm me if you want them.
http://www.hepcnet.net/hepatitiscfaq.html