I'm extremely strict. I'm completely aware that its not probably necessary but for 9 months who cares. The main reason I'm so strict is that when I was 33 weeks with DD1 I ended up being rushed to hospital hideously ill with suspected listeria after eating takeaway chinese food. Turned out not to be listeria but it scared me to death and it is still very vivid in my mind - the sickness I felt, the guilt I felt and the paralysing fear I had for my baby.

As for how common it is, my OB said that in his 30+ years of being an Ob he has only ever seen one case of listeria.