6 Plague Today

This chapter contains a brief overview of plague today (current foci, epidemiology, clinical symptoms, causative agent, treatment, and prophylaxis), as seen from the viewpoint of the medical and scientific community.It is not an ''argument'' but a description of our current observations and understanding of the disease.Three plague pandemics are traditionally described during the Christian era.The first pandemic, designated ''the plague of Justinian'', broke out in Egypt in 541; the second, known as the ''Black Death'', erupted in Messina, Sicily, in 1347; and the third began in the war-torn Yunnan province of China and reached Hong Kong in 1894.The network of steamships and railways favoured a rapid spread of the disease over all continents and the colonization of previously unscathed areas.Major advances in the knowledge of plague were made during the early years of the last pandemic.In 1894, Alexandre Yersin identified the aetiologic agent (Yersinia pestis) and showed that rats are a reservoir of the disease. 1 Four years later, Paul-Louis Simond demonstrated that plague is transmitted by fleas. 2 Thanks to the advent of effective public health measures, mass vaccination in 1934, and antibiotic therapy in 1938, the number of victims reported during the third pandemic was in no way comparable to those of the previous two. Plague TodayDespite a considerable reduction in mortality and morbidity, plague has not been eradicated.Endemic foci persist in Africa, North and South America, and Asia.During the nineteen years from 1985 to 2003, over 43,000 human cases were reported to the World Health Organization by twenty-five countries. 3 The worldwide numbers are most likely underestimated because of unrecognized cases and the failure of some countries to report occurrences of plague.Since the beginning of the 1990s, a sharp rise in the number of human plague cases has been observed (Figure 1).This rise is partly attributable to the reappearance of epidemics in countries or regions where human plague had disappeared for several decades.This was the case in 1991 in the seaport of Mahajanga (Madagascar) after an absence of over sixty years, in 1994 in Malawi, Zimbabwe, Mozambique and India (where no case had been reported during nearly thirty years), in 1996 in Zambia and some provinces of China, in 1997 in Jordan (with no plague cases during eighty years), and more recently in Algeria (2003)