PLAGUE, in medicine, a term formerly given to any epidemic disease causing a great mortality, but now confined to a specific infectious fever caused by b. pestis.
History to 1880.—The first historical notice of the plague is contained in a fragment of the physician Rufus of Ephesus, who lived in the time of Trajan, preserved in the Collections of Ori basins'. Rufus speaks of the buboes called pestilential as being specially fatal and as being found chiefly in Libya, Egypt and Syria. This passage shows the antiquity of the plague in northern Africa, which for centuries was considered as its home. It is not till the 6th century of our era, that we find bubonic plague in Europe, as a part of the great cycle of pestilence, which lasted fifty years, and spread over the whole Roman world, beginning in maritime towns and radiating inland. In another direction it ex tended from Egypt along the north coast of Africa. Whether the numerous pestilences recorded in the 7th century were the plague cannot now be said ; but it is possible the pestilences in England chronicled by Bede in the years 664, 672, 679 and 683 may have been of this disease, especially as in 690 pestis inguinaria is again recorded in Rome.
In the great cycle of epidemics in the 14th century known as the Black Death, some at least were bubonic plague. The mortality of the black death was, as is well known, enormous. It is estimated in various parts of Europe at two-thirds or three-fourths of the population in the first pestilence, in England even higher ; but some countries were much less severely affected. Hecker calculates that one-fourth of the population of Europe, or 25 millions of persons, died in the whole of the epidemics.
The Great Plague of London.—The great plague of 1664 1665 must not be regarded as an isolated phenomenon. Plague had recurred frequently in all parts of Europe in the 15th, 16th and 7th centuries. Nevertheless in London the preceding years had been unusually free from plague, and it was not mentioned in the bills of mortality till in the autumn of 1664 (Nov. 2) a few isolated
cases were observed in Westminster and a few occurred in the fol lowing winter, which was very severe. About May 1665 the disease again became noticeable and spread, but somewhat slowly. Bog hurst, a contemporary doctor, notices that it crept down Holborn and took six months to travel from the western suburbs to the eastern through the city. The mortality rapidly rose from 43 in May to 590 in June, 6,137 in July, 17,036 in August, 31,159 in September, after which it began to decline. The total number of deaths from plague in that year, according to the bills of mortality, was 68,596, in a population estimated at 460,00o, out of whom two thirds are supposed to have fled to escape the contagion. This number is likely to be underestimated, since of the 6,432 recorded deaths from spotted fever many were probably really from plague, though not declared so to avoid painful restrictions. In December there was a sudden fall in the mortality which continued through the winter; but in 1666 nearly 2,000 deaths are recorded.
According to some authorities, the plague was imported into London by bales of merchandise from Holland, which came originally from the Levant ; according to others it was introduced 'Lib. xliv. cap. i7—Oeuvres de Oribase, ed. Bussemaker and Darem berg (Paris, 1851), iii. 607.
by Dutch prisoners of war. From London the disease spread widely over England.
After 1666 there was no epidemic of plague in London or any part of England, though sporadic cases appear in bills of mortality up to 1679; and a column filled up with "o" was left till 1703, when it finally disappeared. The disappearance of plague in London was attributed to the Great Fire, but no such cause existed in other cities. It has also been ascribed to quarantine, but no effective quarantine was established till 1720, so that the cessa tion of plague in England must be regarded as spontaneous.