I know someone who lost a baby in pregnancy from Listeria.
With my first 2, I thought it was just all rubbish and I still continued eating like i would normally, this included cold meats and soft cheese. The boys were fine thank God.
Then I met my friend, she told me about her son, it broke my heart and this time I was careful.
I think at the end of the day you do what you want, but to me now that I know what happens, can happen, has happened, I don't think it is worth the risk for a peice of ham or a bit of kabana.