Re-emerging infections

Abstract

n recent months, influenza has been receiving general interest from the media and serious attention from health ministries around the world as a re-emerging threat. The interest is because of the ability of influenza viruses to mutate in ways that enable them to escape the controlling influence of human immunity and to spread with increased virulence. This article considers why influenza may soon re-emerge, and contrasts the threat of influenza with the re-emergence of a common bacterial respiratory pathogen, Streptococcus pyogenes (also known as the group A streptococcus).