Scourge of the medieval world, the Black Death spread swiftly from the trading ports of 14th-century China through the Mediterranean and up into Europe, leaving a third of the continent's population dead in its wake. The worst disaster ever to befall the modern age may be long forgotten, but it is far from gone, lurking in isolated pockets around the world. In Madagascar, antibiotic-resistant strains are beginning to spread, just as tourists are trekking into its heartland. Plague once came ashore with rats from ships; today it is just a plane ride away
NO DISEASE IN RECORDED HISTORY has carried the totemic power of plague. No disease has erupted with such violence and with such brutal efficiency, nor remained so poorly understood for so long. It was plague that destroyed one-third of Europe's population during the Black Death of the Middle Ages; plague that swept through London in 1665; plague that killed some ten million Indians in the first two decades of the 20th century.
Yet now, at least outside scientific and geographical circles, the perception is that plague is a disease of the past, an infection with a negligible threat--certainly compared to that of Aids, Ebola and resurgent tuberculosis. The late 19th-century discovery that the disease is caused by a bacillus carried by rat fleas, coupled with the use of antibiotics from the 1940s to fight the infection, have encouraged a that plague is now a toothless longer to be feared.
Nothing could be more dangerously misleading. According to World Health Organization (WHO) statistics, close to 24,000 plague cases were reported by 24 countries in the 15 years before 1996; of these, more than 2,000 were fatal. The worst-affected countries were Madagascar, Tanzania, Vietnam and Peru. Since the early 1990s the rate of infection has been increasing steadily, which led the WHO in 1996 to reclassify plague. No longer dormant, it is now a `re-emerging disease'. A 1998 report in the journal Emerging Infectious Diseases blamed "under-reporting in remote areas" along with "the lack of sensitivity of the bacteriological techniques used for diagnosis". The warning bell has sounded.
Of the four worst-affected countries, the one that causes most concern is Madagascar. On this island, the last decade has seen a powerful resurgence of plague. Here, moreover, strains of the bacillus have been found which have developed resistance to all effective antibiotics. In the measured words of Dr Mike Prentice, senior lecturer in medical microbiology at St Bartholomew's Hospital in London, plague is "down but not out". He adds, "Given the resurrection of whatever conditions allowed plague to spread in the first three pandemics [that of the sixth century, the Black Death of the Middle Ages, and the pandemic that began in the 1890s in China and is still with us in sporadic pockets today], there is always the potential that it could come back." In Madagascar, it already has.
The most vigorous and sustained research into plague on the island is being conducted by the Pasteur Institute. This is the organisation that employed Dr Alexandre Yersin, who discovered the cause of plague in 1894 in Hong Kong. The Institute's work reveals that Madagascar is not only in the grip of a medical emergency, but its local customs and beliefs have combined to bring an already grave situation close to critical.
The villain of the piece is the rat, and in the central highlands as well as in the capital Antananarivo, experiments are under way to ascertain the degree to which the rodents are infested with fleas, and what of the fleas are themselves with plague. Slow-acting poisoned bait boxes are set inside houses, with great care taken to ensure the rats wade through insecticide powder before getting to the bait. This is a risky undertaking: if rats die without their fleas being killed, the infected fleas will search for a new host. …