it would not be likely to contract an std in that way but it would be wise to wash that blanket anyway. and have a long talk to your roommates about leaving used condoms lying around. disgusting.
can stds be transferred through indirect contact? . this may seem silly but i'm a hypochondriac so i just really need someone to put my mind at rest. i found a used condom on my floor and i definitely avoided touching it and my roommate came in and picked it up. but i'm pretty sure a blanket had been touching it that i later touched. is it possible that an std (assuming the condom-wearer had one) could have transferred to the blanket and then to me when i touched the blanket? i don't really know if bacteria works like that. i'm concerned.