After decades with no confirmed human plague in India, health authorities there are simultaneously responding to outbreaks of bubonic and pneumonic plague in rural and urban populations of the south central and southwestern states of Maharashtra and Gujurat. A major concern is the spread of disease by travellers from these epidemic foci.1 Worldwide, public health authorities have been trying to prevent the introduction of pneumonic plague within their borders, requiring national disease surveillance and quarantine offices to operate on emergency schedules dealing with a situation with which almost none has any first hand experience.2

Public fascination, confusion, and incredulity have been fuelled by press reports. A mass exodus including hospital patients and even staff themselves has occurred from the epicentre of the outbreak of pneumonic plague despite regular pronouncements by the medical community that plague is readily treated with antibiotics. Assurances of the effectiveness of public health measures have seemed incongruous given the explosive spread of disease, which authorities have been slow to confirm and explain. Doctors and public health workers have quickly tried to educate themselves about a disease they had long considered in the past tense. And everyone asks, “How could this happen?”

Plague is caused by infection with Yersinia pestis, a bacterium carried by rodents and transmitted by fleas in parts of Asia, Africa, and the Americas.2 India was one of the countries most affected by the pandemic of plague that began in the latter half of the 19th century, experiencing an estimated 12.5 million deaths during 1889-1950.4 In recent decades plague in India and elsewhere has retreated to rural, natural foci of infection involving …