Smallpox: implications for infection control practitioners. Part one: disease characteristics and history

Abstract

In this, the first of a two-part article, the history and characteristics of smallpox disease are examined, together with a discussion of vaccination strategies. Since the events in New York on 11 September 2001, there has been renewed speculation about terrorists' abilities to initiate biological warfare using highly infectious diseases such as smallpox. There is no effective cure for smallpox and current infection control strategies rely heavily on heightened surveillance, isolation techniques and vaccination of susceptible individuals. Much of the world's population has neither been exposed to the smallpox virus nor vaccinated against it, and so is vulnerable to infection. Furthermore, many healthcare staff have no experience with diagnosis, management or prevention of smallpox and there is a risk that the disease may rapidly spread if it is not recognised quickly. Smallpox begins with non-specific symptoms that can occur with many viral illnesses; misdiagnosis and delayed diagnosis is a very real risk, even in the presence of a rash. This situation has fuelled debate that pre-emptive mass vaccination against smallpox should be introduced to protect the population from the threat of a deliberate release of smallpox.