Viral infection is a disease caused by micro-organisms, which invade a living cell and use its mechanisms to reproduce. Viruses need to colonise a host organism in order to fulfil its vital functions because it lacks the biochemical organisations that replication requires. This book discusses several topics that include viral infections in obstetrics and gynaecology; the management of HIV infection by Chinese medicine; antiviral activity of lactoferrin; and antiviral effects of phytochemicals of the Mediterranean medicinal plants.