Report on the outbreak of plague at Sydney [1900-1907] / by J. Ashburton Thompson, Chief Medical Officer of the Government and President of the Board of Health.
- New South Wales. Department of Public Health
- Date:
- 1900-1908
Licence: In copyright
Credit: Report on the outbreak of plague at Sydney [1900-1907] / by J. Ashburton Thompson, Chief Medical Officer of the Government and President of the Board of Health. Source: Wellcome Collection.
Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.
235/452
![buildings connected with it, and from some closely adjacent streets of the city, being localities in which experience had shown that recurrent plague was most likely first to show itself. Thus, on 28th February, 1904, it appeared probable that Sydney had been free from plague in its rats for more than six months, as it certainly had been free from plague in man. 8. During the second, or epizo5tic, period which dated from 1st March to 3rd December, 1904, the number of rats destroyed was 61,657, of mice, 47,279; total, 108,936. Of these, 41,263 rats and 23,85i mice, total 65,114, were brought in by the public, and were paid for as above-mentioned. None of them were examined. The intelligence stafl'delivered 20,394 rats and 23,428 mice (total, 43,822), all of which were examined at the laboratory, at the rate of about 182 a day. Among them, 181 rats and 62 mice, total 243, were found to have had plague ; the remainder were free from this infection. Additionally, 13 other animals were referred for examination, namely, 5 domestic cats, 1 opossum, 5 native-cats [Dasyurus viverinus, Shaw), 1 tiger-cat {Dasyurus maculatus, Kerr), and 1 sparrow {Passer doniesticus). Plague was identified in 1 domestic cat, and this was the second in which this infection had been observed at Sydney {see Report, 1900, p. 39). Besides the above-mentioned animals, the infection of plague has been identified at Sydney by Tidswell in the folhjwing, which had become exposed to it in a zoological gai'den :—4 wallabies, 1 wallaroo, 1 pademelon, and 1 tree-kangaroo (all of which are marsupials), in 1 Indian antelope, and in 3 caged guinea-pigs. As plague had not previously been observed in marsupials, the methods employed to discover and to discriminate the bacillus were of the highest importance ; they were, therefore, described at length (Report, 1902, parts 157-163), although they differed not at all from those usually followed in this laboratory in connection with plague-work in general. No other animals, and especially none of the farm-yard species, have fallen under suspicion of infection in this part of the world. Simpson and Hunter, working at Hongkong, have reported that various domestic animals (pigs, calves, fowls, turkeys, geese, ducks, pigeons. Arc.) were infected experi- mentally by them, and that the pigs often survived for more than a month, during which they ofi'ered no evident sign of illness except an increased body temperature, although they died of plague at last. (Simpson : Report to the Secretary of State for the Colonies on Plague at Hongkong, 1903, pp. 49-103.) The evidence adduced by the authors in suf)port of their conclusions was meagre. Bacteriological methods and results, and the experimental conditions in general, were not adequately described, so that their state- ments amounted to little more than assertions, notwithstanding clinical accounts of the cases. Confirmation must, therefore, be awaited. These experiments were repeated in Natal by Mr. H. Watkins-Pitchford, F.R.C. V.S., Government Bacteriologist, who reported upon them, and Dr. Haydon. (Report on the Plague in Natal, 1902-3; by Ernest Hill, M.R.C.S., D.P.H., Health Ofiicer for the Colony. Cassell & Co., London, 1904). The series of animals employed comprised 20 barn-yard fowls, II pigs, and 2 calves. The results were uniformly negative ; plague was not communicated in any instance. The details were so completely given by Mr. Pitchford that little was left wanting. 9. During the third, or ensuing plague-free period, which dated from 4th December to 31st December, 1904, 5,435 rats and 2,796 mice, total 8,231, were destroyed. Of these, 3,504 rats, and 1,582 mice, total 5,086, were brought in by the public, and none of them were examined. The intelligence staff delivered 1,931 rats and 1,214 mice, total 3,115, all of which were examined at the laboratory, and all were found to be free from infection with plague. 10. The several species of rodents examined in the laboratory during the whole of the year 1904, and the proportions in which they occurred, can be stated. The total number was 52,014; 35*43 per cent, of them were 3Ius decumanvs, 1406 per cent, were 3Ius rattus, and 50'47 per cent, were Mus nmsculus. 11. Tlie number examined during the epizootic period alone was 43,822 ; 32'15 per cent, of them were 3Ius decmnanns, 14 36 per cent, were 3Ius ralfus, and 53'44 per cent, were Mus musculus. 12. Of those which were found to be infected with plague, 108 were Mus decumanus, 73 Mtis rattus, and 62 Mus musculus, and these constituted respectively 44*26 per cent., 29'92 per cent., and 25 41 per cent., of the total (243) infected. 13. The percentage of each species infected to the total of each species examined during the epizootic period was for Mus decumanus '76, for Mus rattus 116, and for 3Ius musculus 26 ; or, for all rats 9, and for mice but 26, although the number of mice examined (23,428) exceeded the number of both species of rats taken together (20,394.) As all these rodents were collected by the same staff, Avorking on the same areas, ]ierhaps some reason appears for supposing that mice may be less susceptible than rats to natural, as they are to laboratory, plague. In con- nection with the small joroportion of the infected to the total rodents examined during this period, remarks already made (Report, 1903, pars. 13 to 15) should be rej^erused. 14.](https://iiif.wellcomecollection.org/image/b21354704_0235.jp2/full/800%2C/0/default.jpg)
