MedicalNewsToday.com - Looking at "five emerging and re-emerging diseases - malaria, lyme disease (spread by ticks), Hantavirus (spread by mice and rats), West Nile disease (spread by mosquitoes), and schistosomiasis (spread by freshwater snails). They argue that changes in land use, farming practices and climate lie behind the increasing number of outbreaks." http://www.medicalnewstoday.com/articles/175091.php