Nicholas Bakalar 
Where the Germs Are [PDF ebook] 
A Scientific Safari

A guided tour through the strange and sometimes dangerous microscopic world
Germs are everywhere–in our intestines and on our skin as well as on kitchen counters, public toilets, doorknobs, and just about everything else. Why are there so many microorganisms? Which ones are dangerous? And how can we avoid the ones that will make us sick? This entertaining and informative book provides the answers. Profiling a rogue”s gallery of harmful germs–from the influenza virus, salmonella, and herpes to hepatitis, tuberculosis, and HIV–as well as helpful microbes (we actually need E. Coli and other bacteria for proper digestion), the book reveals how different germs interact with the human body and what happens when they do.
Nicholas Bakalar (New York, NY) is the author or coauthor of ten books, including Hepatitis A to G and Wiping Out Head Lice.