Thanks for all the comments.

I don't eat fish of any kind, so I should be fine on that point. I also don't plan on consuming any liquids that don't come out of a bottle, nor do I plan on consuming ice. I'll look into whether my hotel (Melia Cabo Real) has a water treatment system, though I don't know if I'll believe them even if they tell me they do.

My concern has more to do with food preparation staff carrying hepatitis, and whether they then transfer the illness to my prepared food.

It sounds like you all would err on the side of caution and would get the shot (or already have done so!). My complicating factors are a/ my husband donates blood products regularly and would no longer be able to do so if he got the shots, and b/ I was once immuno-compromised and prefer not to overload my immune system with vaccines unless I absolutely can't avoid it (and in fact I am forbidden from receiving live-virus vaccines, though the hepatitis vaccine isn't live-virus).

I'll give the matter some more thought.