Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Smallpox is an infectious disease which emerged more than 3,000 years ago in India or Egypt. The disease is caused by variola virus and is known as one of the most devastating diseases in human history – it has caused great suffering and killed 30% of infected individuals. In 1967 the World Health Organization launched its global smallpox eradication campaign and the last naturally occurring case of smallpox infection was documented in 1977. Learn more about the disease, its causes, symptoms and treatments as well as its eradication in this book.