Lyme disease is a bacterial infection caused by the bite of certain, very small infected ticks. The illness is characterized by a circular rash of 2 inches or more with a bull's-eye appearance. If untreated Lyme disease can cause further problems involving the heart, joints, and nervous system. Lyme disease can be treated effectively with antibiotics. Travelers visiting Western European countries who will be hiking, camping, or visiting rural areas are at risk of Lyme disease.
Yellow fever is a viral disease found in parts of Africa and South America.
It is transmitted to humans by a mosquito bite. If you are ONLY traveling from the United States to a Western European country, CDC does not recommend, and you are not required to have a yellow fever vaccination. However, if your travel plans include traveling to or from a country in Africa or South America, you may be required to have a yellow fever vaccination. To reduce mosquito bites travelers should remain in well-screened areas, use mosquito nets, and wear clothes that cover most of the body. Travelers should also take insect repellent with them to use on any exposed areas of the skin.