The “Black Death.”—The most noted epidemic of plague was that of the “Black Death” of the 14th century. The disease seems to have originated in the East, possibly in China, and eventually invaded Asia Minor, Egypt and Europe. The disease was called “Black Death” in Germany, on account of the petechial spots or “tokens” and in Italy, the “Great Mortality.”
In the records of the epidemic we note that it was attended with great stupefaction, the sick losing their speech from palsy of the tongue. Others noted buboes of groins and arms while some noted a putrid inflammation of the lungs with the expectoration of blood. In the plague at Avignon it was noted that at first, for six or eight weeks, the sick expectorated blood and that to come near them was certain death. Afterwards buboes appeared in groin and axilla and some of the sick recovered.
Quarantine.—It was during this epidemic that quarantine became a recognized procedure in Europe. The adoption of a period of detention of forty days probably originated in the medical idea that the 40th day was the last day of ardent diseases, this being one of the critical days. The lazarettos, where strangers were held in quarantine, appear to have first been established on some island near Venice, in 1485.
It has been estimated that one-fourth of the population of Europe succumbed to the “Black Death,” but estimates in certain parts of Europe would indicate a mortality approaching 70% of the inhabitants.
In 1665 occurred the Great Plague of London, during which year it was estimated that approximately 60,000 out of a population of 450,000 died. It was thought that this epidemic was introduced from the Levant by way of Holland.
There was much plague in Europe in the 18th century but it would seem to have completely disappeared by 1841 and only to have returned with the present pandemic.
The Present Pandemic.—The plague epidemic with which all parts of the world are now so concerned is supposed to have originated in China, in the province of Yunnan, and from that center to have reached Canton, in 1894, causing the death of 60,000 people in a population of 1,500,000. In the same year it extended to Hong Kong and from that great seaport has spread over the entire world. India has suffered more than any other country, there having been years when the plague deaths exceeded 1,000,000.
In a recent article by Low it is noted that the highest death rate was reached in 1907 when 1,315,892 persons died. From the time of the introduction of plague into India to the end of 1917 there were 9,841,396 deaths from this disease.
In its spread it has invaded Europe, Egypt, South Africa, Australia, Japan, Philippine Islands, California and parts of Central and South America. It has recently made its appearance in New Orleans.
Geographical Distribution.—At present there are only two important foci of endemicity, one Mesopotamia and another in the region of the Himalayas (India, Thibet and Yunnan). There also seem to be less important centers in Uganda, in Africa, and in the trans-Baikal region of Siberia. In view of the rather widespread infection of the California ground squirrels, from which rodents the disease has from time to time spread to man, it would seem probable that California might be considered another focus of plague.