Date Published: January 15, 2008
Publisher: Public Library of Science
Author(s): Nils Chr Stenseth, Bakyt B Atshabar, Mike Begon, Steven R Belmain, Eric Bertherat, Elisabeth Carniel, Kenneth L Gage, Herwig Leirs, Lila Rahalison
Abstract: The authors argue that plague should be taken much more seriously by the international health community.
Partial Text: Recent experience with SARS (severe acute respiratory syndrome)  and avian flu shows that the public and political response to threats from new anthropozoonoses can be near-hysteria. This can readily make us forget more classical animal-borne diseases, such as plague (Box 1).
The plague bacillus causes a rapidly progressing, serious illness that in its bubonic form is likely to be fatal (40%–70% mortality). Without prompt antibiotic treatment, pneumonic and septicaemic plague are virtually always fatal. For these reasons Y. pestis is considered one of the most pathogenic bacteria for humans.
Plague has given rise to at least three major pandemics. The first (“the Justinian plague”) spread around the Mediterranean Sea in the 6th century AD, the second (“the Black Death”) started in Europe in the 14th century and recurred intermittently for more than 300 years, and the third started in China during the middle of the 19th century and spread throughout the world. Purportedly, each pandemic was caused by a different biovar of Y. pestis, respectively, Antiqua (still found in Africa and Central Asia), Medievalis (currently limited to Central Asia), and Orientalis (almost worldwide in its distribution) [12,13].
Given this history, plague is often classified as a problem of the past. However, it remains a current threat in many parts of the world (Figure 1A), particularly in Africa, where both the number of cases (Figure 1B) and the number of countries reporting plague (Figure 1C) have increased during recent decades. Following the reappearance of plague during the 1990s in several countries, plague has been categorised as a re-emerging disease [20,21].
Plague cannot be eradicated, since it is widespread in wildlife rodent reservoirs. Hence, there is a critical need to understand how human risks are affected by the dynamics of these wildlife reservoirs. For example, the likelihood of a plague outbreak in North American and Central Asian rodents, and the resulting risk to humans, is known to be affected by climate [43,44]. Recent analysis of data from Kazakhstan  shows that warmer springs and wetter summers increase the prevalence of plague in its main host, the great gerbil. Such environmental conditions also seem to have prevailed during the emergence of the Second and Third Pandemics [46,47]—conditions that might become more common in the future .