Reports and papers on suspected cases of human plague in East Suffolk and on an epizootic of plague in rodents.

Date:
1911
Catalogue details

Licence: In copyright

Credit: Reports and papers on suspected cases of human plague in East Suffolk and on an epizootic of plague in rodents. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    anil forwarding the rats were undertaken by l)rs. Bulstrode< i'letcher, and Reece. The rats were sent to Ipswich, where they were received and particulars tabulated by Mr. C. J. Huddart on behalf of the Board. The examination of rats was entrusted to Drs. Petrie and Macalister, of the Lister Institute, and was carried out at a laboratory which had been gratuitously placed at the disposal of the Board by the Ipswich Town Council, and prepared for the purpose by Dr. Pringle, medical officer of health of that borough. The system of examination adopted consisted of a primary post-mortem examination of each rat. If any suspicious signs were visible, a bacteriological examination was made; and if this did not enable a negative diagnosis as regards plague to be made, the examination was remitted to the Lister Institute for more complete experiments. The report by Drs. Petrie and MacAlister on their laboratory work is given on page 56; and on page 86 will be found a tabulated summary of the number and sources of rats examined, which has been prej)ared from Mr. TIuddart’s records. This tabulated summary .should be considered in connection with the map facing this page. Altogether 6,071 rats wen* received fioni 22 urban districts, and from 301 parishes in 15 rural districts. Of this number 6,017 were declared negative on post-mortem examination, 43 on further cultural te.sts at Ipswich, and 8 after further examina- tion at the Lister Institute. The remaining 3 rats, which did not manifest very susj)icious features on po.st-mortem examination, yielded on culture an organism similar to bacillus pestis. This bacillus on further examination (xee i>age 61) is regarded as the bacillus pseudo-tuberculosis rodentium. The diagrammatic map facing this page shows clearly the area under observation in this delimiting experiment, and the position of the parishes from which rats were obtained for examination. SciE.xTiFic Work on Rat Fi,ea.s. A report is included (pages 41 to 55) by Drs. C'. J. Martin and Sydney Rowland, of the Lister Institute, on epizootic plague in East Anglia, with special reference to the fleas infesting rodents. As is well known, the chief flea infesting the ordinary black rat of India is the Xeiiopsylla cheopix, which readily bites man. No black rats were found in Suffolk; and the exami- nation of the brown rats showed that they are infested with about equal numbers of two species of fleas, Ceratophi/lhix fasciatus and Ctenopthalmus agyrtes. Of the.se, the former readily bites man; and Dr. Martin found the bacillus pestis in the stomachs of some fleas of this species removed from plague-infected rats. The second kind of flea does not readily bite man. It is noteworthy also that the number of fleas was small. From 568 rats examined, only 584 fleas were obtained. Omitting the Ctenopthalmus agyrtes, which does not seem to bite man, the effective prevalence in Ea.st Anglia is only about one flea to two rats. This, as Dr. Martin points out, “is an infesta- tion which was not found sufficient to give rise to a human