Diseases caused due to infection are known as infectious diseases. Infection is the invasion of the tissues of an organism's body by disease-causing agents, the toxins they produce, and their multiplication. Infectious agents like bacteria, viruses, nematodes, arthropods, fungi and other macroparasites can cause infections. Some common signs of infection include fever, weight loss, fatigue, night sweats, aches, pains and lack of appetite. Antibiotics, antivirals, antifungals, antiprotozoals and antihelminthics are some of the common medicines used to treat infections. This book aims to shed light on some of the unexplored aspects of infectious diseases and the recent researches in this field. It provides significant information of this discipline to help develop a good understanding of infectious diseases and related aspects. It will provide comprehensive knowledge to the readers.