I agree on the ebola but not dengue fever.
excerpt:
“Mexico and Central America harbor TB, malaria, yellow fever, food and waterborne diseases, dengue fever, filariasis, leishmaniasis, onchocerciasis, American trypanosomiasis (Chagas disease), and myasis (various forms of intestinal parasites). Mexicos six border states have over 27 cases of TB per 100,000 people. Legal immigrants have to be evaluated for TB and other diseases before they are allowed into the U.S. Illegal aliens escape such inspection.”
http://canadafreepress.com/index.php/article/63834
Dengue Fever is not contagious.