This updated manual provides a basic understanding of the principles of laboratory and point-of-care (POC) testing in the context of screening and diagnostic approaches, as well as antimicrobial susceptibility testing, as components of sexually transmitted infections (STIs) control. As with previous editions, this manual covers each disease in a separate chapter which provides detailed information on specimen collection, transport and laboratory testing. Two useful annexes covering media, reagents, diagnostic tests and stains (recipes) and laboratory supplies are included at the end of the manual.