Scientists discover 21st century plague

"Bacteria that can cause serious heart disease in humans are being spread by rat fleas, sparking concern that the infections could become a bigger problem in humans. Research published in the December issue of the Journal of Medical Microbiology suggests that brown rats, the biggest and most common rats in Europe, may now be carrying the bacteria. Since the early 1990s, more than 20 species of Bartonella bacteria have been discovered. They are considered to be emerging zoonotic pathogens, because they can cause serious illness in humans worldwide from heart disease to infection of the spleen and nervous system" - EurekAlert