Epi Info is a free computer program from the Centers for Disease Control and Prevention(CDC), downloaded 2 million times since 1998, and referred to in over 1 million web pages. It allows anyone with a computer to design a questionnaire, enter data, and do tabulation and statitistical analysis. This book tells how to use Epi Info for rapid surveys and research studies and for constructing electronic medical records, public health surveillance systems. graphs, and maps. Sample programs can be downloaded from the web.