Rabbits can get ear mites from direct contact with other rabbits, from being outside, and from our hands if we have recently handled an infected rabbit and then pet our own rabbit without washing.
«The scientists found that the naturally evolved weakening of the virus is actually beneficial for the virus because infected rabbits lived longer and were able to better transmit the virus.»
1990 — Researchers at the University of Rochester combine antibodies from infected rabbits with the live virus; the proof-of-concept vaccine successfully prevents foreskin-grafted mice from contracting HPV on their borrowed private parts.
Louis Pasteur developed the first rabies vaccine, made from the dried spinal cords of infected rabbits, and famously used it to save the life of a 9-year-old Parisian boy in 1885.
Since the pinworm is a direct life cycle with NO intermediate host, this means your rabbit got it from the feces of an infected rabbit (it didn't just happen to your rabbit).