Although we don't live in same fear as our predecessors from a few centuries ago, the threat of infectious diseases is still very real. There are diseases that decimated countless numbers of the population in earlier times that are preventable today due to vaccines. Some diseases that used to be deadly are now treatable with antibiotics. There's little doubt that we live in a time of incredible medical advances. However, just because health conditions have greatly improved that doesn't mean the threat of certain types of diseases is gone.
Outbreaks can be caused by parasites, bacteria, viruses, and fungi. Some are caused by bites from insects or animals. These occurrences can happen anywhere, however outbreaks are often more common in other countries, particularly third world countries that do not have the same types of environmental practices as other places. People who are traveling abroad should do research regarding risk factors and how to minimize them. This includes being aware of out brakes in area and surroundings that you are going to.
Exposures to different conditions in environment is a factor that must be taken into consideration before traveling. One risk is ingesting contaminated food or water. Many countries have purification systems and strict rules about food, but there are many more who don't. If you aren't sure, invest in bottled water or even get your own purification system. There are tablets that can be put into water to purify it. There are also other ways that it can be done. Research what might work for you on your travels - consider it an investment toward your good health while you are away from home.
There are certain areas of the world where diseases such as measles and chickenpox are still making people ill. It might be a good idea to visit your doctor and get a booster of some of the vaccinations you received years ago. Keep in mind that while some of these diseases are fairly mild, they can lead to other complications. Another good idea is to stick to a stringent hand washing routine. Wash your hands multiple times a day and use hand sanitizer as well. This will help keep your germ exposure to a minimum - something that will definitely add to the enjoyment of your time while traveling!