has anyone else experienced what my friend calls the 4 day flu in DR. I have visited twice and i get the flu after 4 days there. I have all my booster shots and even took a flu shot weeks before i traveled. No insect bites, normal diet, no travelers diarherria, i never drink the local water, but i do take showers with the water. I don't brush my teeth with it though. I've heard that i need the floride that is in my native country (USA).