The times when the majority of diseases were treated by bleeding are over! Medicine has developed very fast during the last century and nowadays even such a dreadful disease as hepatitis A can be easily treated and even cured if a patient has address his or her general practitioner in a timely manner. It is always to be prepared and take the necessary precautions than to catch a disease and then to treat it. But unfortunately we understand this when it is late and when only medical interference is the only way to save a patient’s life.
The same may be said when you desire to travel to the countries that are in a high risk zone, it means that you are to apply for traveler vaccination before your trip to be on a safe side especially if you travel to the countries of African or Asian regions. Nothing can guarantee that you won’t catch a disease even if you have undergone a special immunization but the latter increases your chances to fight, for instance, a whooping cough or to save your stomach from malnutrition if you eat something exotic or drink something that is completely undrinkable for an European.