Yersinia pestis, a problem of the past and a re-emerging threat

Yersinia pestis is the bacteria that causes plague, one of the deadliest diseases in human history. Three major plague pandemics (the Justinian Plague, the Black Death and the Modern Plague) have been recorded. Each caused massive fatalities and has become defining events in the time periods in places that were affected. The presence of natural plague foci in rodents across the world is one of the risk factors for human plague. While plague is a relatively rare problem for most countries, more than 90% of plague cases in the world still occur in Africa. This article discusses the threat of Yersinia pestis in the modern world by considering its prevalence and severity of illness it causes, transmission, antibiotic resistance, and its potential as a bioweapon.