PUBLIC RECORD OFFICE
Reference :-
CO885
7
PUBLIC RECORD OFFICE, LONDON
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
Yunnan, in China.
The identity of rat plague
and human
plague
established
in the
epidemic at
in 1994.
4
outbreak of mahamurree was the death in the first instance of the rat." In Syria, also, the mortality among rats was well- known to be the accompaniment of plague.
3. In Yunnan, another centre of plague in which the discase has been endemic for at least 50 years, it is to be gathered from the reports of the French Missionaries and of M. Rocher, now the French Consul in Liverpool, who visited Yimugn in 1870, that the Chinese inhabitants are acquainted with the rat mortality preceding outbursts of plague. The rats, it is stated, are first attacked, and when they sicken they leave their holes in troops, stagger about, fall over each other, and drop down dead. From the fact of the rat mortality preceding the plague, the Chinese hold that plague is a soil disease.
In Canton, in 1894, no fewer than 22,000 dead rats were buried outside one of the principal gates of the town by Chinese officials at the commencement of an epidemic of plague which destroyed 80,000 of the inhabitants.
It was further observed in this epidemic that when plague continued for some time in a district the rats disappeared, while in those districts where the mortality among the rats began to increase there the plague also extended.
4. Rat mortality and plague again showed themselves together in the epidemie at Hong Kong in 1894. Hitherto the connection between them was founded only on the frequency with which they had been observed preceding or accompanying one another, and the relation to each other, though a matter of common opinion in the endemie areas, had never been absolutely proved. Now, Hong Kong however, by the discovery of the plague bacillus in man, and the observations ami experiments which this discovery permitted to be made Kitasato and Yersin were able to establish that mice and rats could be infected with the plague bacillus, causing in them a similar disease to plague in man, the principal lesions being buboes, extravasations, and congestions in the internal organs, and that when this disease was produced in ruts and mice the glands and organs contained the bacillus in extraordinary numbers.
The practi.
of tho
5. The importance of these facts, in conjunction with the el bearing often-repeated history of rat mortality and plague, is immense, discovery in especially in regard to its practical bearing on the prevention of Hong Kong plague. It is a matter of great concern that its importance is not realised not sufficiently realised to be put into practice everywhere, even in the early stages of the at the present day. It was not realised in 'the early days of the plague in Bombay in 1896, for when attention was called to the enormous number of dead rats it was ascertained that for more than a month previous to the outbreak in Mandvie rats had been observed to have been dying in unusual numbers. Dr. Surveyor found the plague bacillus in the rats found dead in large numbers in the grain depôts, streets and drains of the city, and proved by
Bombay
epidemic in 1896, but
put into suc- cessful use in Calcutta in 1896.
the cultural tests to which he subjected the bacillus that it wae the same as the plague bacillus in man.
Later in the year certain cases of plague appeared in Calcutta, and in a grain depot with business relations with Bombay rats began to die. They comported themselves in the same way as recorded in those localities 'where the unusual occurrence had proved to be the precursor of plague. They left their usual hiding places and came out into the open in great numbers. They were very ill, and in a dazed or stupified condition, their eyes were watery and bleary, their coats partially deprived of hair, and they hobbled about with difficulty, staggering and falling over one another. They had lost their timidity for man in their evident desire for fresh air, and they failed in energy even to attempt to escape when approached. The sick and the dead were heaped together. In one day 100 dead were found. Sick rats killed and examined had their glands in the groin axilla or neck enlarged, congested and agglutinated together, their internal organs congested, and their spleen and liver enlarged and full of plague bacilli.
Profiting by the occurrences in Hong Kong and Bombay, it was determined to make strenuous efforts to stamp out the rat plague, which appeared only to be the precursor of human plague. For this purpose the floors were taken up, the rats were killed, and the floors and runs were flooded with crude carbolic acid, with the result that the epidemic among the rats whose mortality had mounted up to 100 a day, was arrested. Similar treatment of some of the adjacent houses to which rats had migrated put an end to the epidemic, and no cases of plague occurred in that locality.
278
on the rat
6. During the first epidemic of plague in Bombay, some very Further important observations were made bearing on the influence of observations. the rat, as an agent in the propagation of plague. It was noticed in the Bom- that the infection was limited in epidemic form for a long time bay epidemic to the first locality affected, notwithstanding that there was a na a dissemi- great exodus of the inhabitants from the infected centre to other nator of districts of the town. This could not be explained by supposing plague. that all who fled were healthy people, for some of the refugees- died from plague immediately they had reached the districts. It was further observed that the infection did not follow the line of the greatest emigration of the inhabitants, but closely corre- sponded with the emigration of and mortality among the rats. Whenever there was a mortality of rats in one of the districts. it was a sure precursor of plague, and until the mortality of rats occurred the district was comparatively free of plague. This mortality of rats usually began in the warehouses and grain depôts which had business relations with each other, and from the rats it spread to the workmen in these warehouses and grain depôts. Similar facts were noticed also in the jails. The jail which kept free from a rat mortality was also free from plague, but the jail