score:3
It seems from the CDC's details page on DR that their concerns boil (sorry) down to two main issues, both of which you should be ok with if you've had your vaccinations - Hep A, and Typhoid.
It's worth noting that the Australian Smart Traveller website has a concern about cholera as well:
Cholera and other infectious diseases
Confirmed cholera cases continue to be reported in the Dominican Republic. Cholera causes diarrhoea and vomiting and can be fatal if left untreated. Correct food hygiene and preparation are essential to minimise the risk of contracting cholera. Water-borne, food-borne, parasitic and other infectious diseases (including hepatitis, filariasis, and leptospirosis) are prevalent, with serious outbreaks occurring from time to time.
Drink only bottled or boiled water. Avoid ice cubes. Avoid uncooked and undercooked food. Ensure correct food hygiene and preparation.