I went to Tesco this afternoon and they had crab claws half price. I bought them because I like to sit there on a saturday evening having various bits of shellfish, especially ones you peel/crack. I bought shell on prawns as well. But after browsing the aisles for over and hour, getting home and unpacking they seem to be half defrosted. I really didn't want to eat them tonight and have shoved them in the freezer. How likely am I to get severe sickness. Has anyone ever done this or do it regularly and lived to tell the tale? It was frozen/half defrosted/frozen again, then it will be defrosted ready to eat saturday.
There is a risk that bacteria on the shelfish bbecame active when the temperature increased, and get busy multiplying, and will do so again when you defrost them again, so make sure you cook them thoroughly.
If there where no bacteria on thwem in the first place, defrosting and refreezing won't make any difference.