Kohn compiles informative entries, maps, and illustrations alongside dull, poorly written, and oddly dehumanized commentaries, particularly the spotty coverage of the Spanish Influenza of 1917-1919. Surprisingly overlooked is the threat of smallpox to the Continental Army during the American Revolutionary War, a subject admirably covered in Elizabeth Ann Fenn's Pox Americana. Also omitted are entries on leprosy, trachoma, and Lyme disease. Indexing is thorough, but tedious and difficult to use. How has so weak a reference work advanced to a third edition?