Just got back from Varadero. My family of 4 took Dukoral, My self, my husband and our boys age 15 and 17. My parents did not and my sister did not. We went to Havana for the day and My sister and I shared my shrimp and her hamburger, it came as two smaller ones so she gave me one. She got sick , vomiting and diarrhea. She was sick for a day.Me nothing. Was my burger just a good one or was it the Dukoral? I wish I knew. My mom also go sick, diarrhea for a day as well. So the 4 of us who took Dukoral never got sick. Our boys ate everything under the sun, lots of meat and never got sick. I ate fish and the prawns mostly. The boys were told if some meat is pink do not eat it, Or if they thought it was not cooked good to leave it. I am not pushing Dukoral I use it for our family and will continue to do so. It is you and your doctors choice. For us our Doctor and pharmacist said it was a good idea.