stupid study because they asked a limited amount of travelers from the UK, so there are all sorts of bias, and clearly Spain tops the list because brits go there to get shitfaced drunk.
I'm sure of the 3000 people they interviewed, not enough had gone to Burundi or Laos to give them a reliable statistic of the safety of street food in those countries.
What I do to stay safe is:
1. Don't trust drinkability of water, especially in less developed areas or old houses, until you know for certain. In Europe usually use it to wash my teeth though as in Europe it's mostly toxicity issues rather than bacteria or parasites.
2. Don't eat salad put as a decoration on your plate
3. Avoid ice
4. Don't order salad or fresh raw vegetables at all when in less hygienic countries
the only time I got really sick to the point I'd call it food poisoning it was due to cooked food on a ship that probably wasn't stored properly, can't do anything about that.....