If these germs infect adults, they may cause listeriosis or toxoplasmosis, but may cause little harm.

http://www.patient.co.uk/health/planning-to-become-pregnant

Raw meat is sometimes contaminated with germs, such as listeria and toxoplasma. If these germs infect adults, they may cause listeriosis or toxoplasmosis, but may cause little harm. However, these germs can cause serious problems to your unborn child if you become infected when you are pregnant.