I wouldn't worry so much about either the water or fruits and veggies in and of themselves. I treat them exactly as I would back home in Canada when I am using them here. Your bigger worry (as in the rest of the world) is unwashed hands or cross contamination (the cutting board used earlier in the day for the raw chicken also being used for cutting the vegetables). And of course, if you travel to the east side of the island, be mindful that the lack of electricity may mean food hasn't been held at the right temperatures. If you see a restaurant packed with locals, you can safely assume the hygiene is good and people don't get sick eating there, since word would get around fast otherwise.