PBS NewsHour’s blog “The Rundown” examines “a recent slate of independent studies” that assert “Twitter can accurately track the spread of a virus or disease – and do it much faster than traditional surveillance methods.” “From Iowa to Brazil, researchers are discovering there is a distinct association between complaints, worries and random rants on the social media site and the spread of medical issues as wide-ranging as the flu, dengue fever and pollen-induced allergies,” the blog states (Khan, 8/9).