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

  • Great Britain. Local Government Board.
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 Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    ?0 Woodbri(l{]^e and Felixstowe urban districts, without the occur- rence of one case of Imman plague. It must, too, be reineinbered that this rat destruction was for the most ]>art carried out by persons who were unaware of or, at least, who did not fully appreciate the danger which they might be incurring from rat fleas, and that, consequently, notwithstanding advice which was given them, few precautions were taken to prevent the trans- mission from rat fo man of ])ossible jdague-infected fleas. The explanation of this human immunity may in part be due to the fact that the rat destruction process took place in the open country during the winter months when the rat flea population in this country is probably at its lowest. But there may probably be a more dominant factor at work in the circumstance, that the rat which is in question in this country is, for practical purposes, exclusively Mus Norvegicus vel decumanus, the habits of which are essentially different from those of the black rat of India (Mus rattus), which is largely a domesticated animal, and which, from the circumstances of Eastern life, is brought far more intimately into relation with the human population than is the case with Mus decumamis, which inhabits mainly the hedgerows and stacks and which largely avoids the vicinity of man. Moreover, the rat flea of Miis rattus is Xenopsylla cheopis formerly known as Pulex cheopis, which bites man readily and which infests the rats freely. The investigations of Drs. Martin and Rowland, an account of which follows, tend to show that at any rate in East Suffolk the rat-flea population in the winter mouths of 1910-11 was a very scanty one, averaging under one flea per rat, and that the Xenopsylla cheopis was absent. Moreover, more than 50 per cent, of this rat-flea population was made up of Ctenoph- thalmus agyrtes,* a flea which, so far as the limited experiments carried out up to the present indicate, rarely, if ever, bites man; the remainder of the rat-flea poimlation being composed of Ceratophyllus fasciatus, which bites man,* but not nearly so readily as does Xenopsylla cheopis. There is thus left on the average less than half a man-biting flea per rat. As further bearing upon the immunity of the human popu- lation in East Suffolk, attention may be directed to some experiments carried out by the Indian Plague Commission as to the transmission of plague by fleas.J In the course of this investigation, some experiments were conducted with the view of ascertaining whether a single flea taken from a septicaemic-plague rat could transmit the infection to the white English rat, which, as is well known, is extremely suscej)tible to plague. Out of 67 experiments made, only in one instance was plague transmitted through the agency of a single flea, although it was estimated, on the basis of some previous experiments. • Of the 584 rat fleas 324 were Ceratophyllus fasciatus and 259 Ctemphthalmus agyrtes.