The swath of the earth lying between the Tropic of Cancer and the Tropic of Capricorn is home to a variety of severe endemic diseases including: malaria, dracunculiasis or Guinea-worm disease, schistolomiasis, trematode infections, onchocerciasis, leishmaniasis, denge fever, and sleeping sickness. For travelers concerned about possible exposure to both tropical and other diseases, the CDC Travel...