Chikungunya and Zika viruses provides the primary "go-to" source for both historical and current information on these increasingly important human pathogens. Both viruses are newly emerged pathogens that have recently become established in greatly expanded global ranges, to threaten hitherto unexposed populations. Epidemics since 2004 have spread from Africa and Asia to Europe and have caused millions of cases in the Americas. The viruses have probably established themselves in South and Central America permanently leaving millions at risk for future infection. Chikungunya virus (CHIKV) causes severe crippling arthritis and symptoms that can last for months or years. Infections with Zika virus (ZIKV) have been associated with potentially fatal neurological symptoms notably to children of women infected during pregnancy. There are no approved vaccines or specific treatments available. Chikungunya and Zika viruses contributes significantly to our understanding of these pathogens. This dedicated monograph brings this combined knowledge together to provide a single up-to-date source of information.--