Further preliminary reports on flies as carriers of infection.

Date:
1909
Catalogue details

Licence: In copyright

Credit: Further preliminary reports on flies as carriers of infection. Source: Wellcome Collection.

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    in 21 numbers; (2) Eye trouble occurs in the same places where flies are numerous (Delta of the Nile); where there are a few flies (The Desert) there are also few cases of illness ; (3) Natives and especi- ally children are remarkably indifferent to the attacks of flies, they allow the flies to settle in crowds about their eyes, sucking the secretions, and never think of driving them away ; (4) Examination of the flies captured on diseased eyes revealed bacteria on their feet which were similar to those found in the conjunctival secretion. Other authors are quite in agreement with Howe in this matter (see Fuchs, 1894, p. 211). That gonorrhoeal and other infections of the eye may be caused by flies is generally agreed (Braux, 1882 ; Demetbiades, 1894 ; German, 1896). Welander (1896) observed an interesting case wherein an old bedridden woman in a hospital became infected. This patient’s bed was alongside of that of another patient who had blennorrhoea, but a screen, which did not reach to the ceiling, separated the beds. All means of infection, except through the agency of flies, appeared to be excluded. Wellander found that flies bore living Gonococci upon their feet three hours after they had been soiled with secretion, for they infected ascites-agar plates with which they came in contact. The evidence regarding the spread of Egyptian ophthalmia by flies appears to be conclusive, and the possibility of gonorrhmal secretions being conveyed by flies cannot be denied. PLAGUE. Although it cannot be claimed to-day that house flies play a part of any moment in the spread of plague it is a matter of some interest to note what has been recorded on the subject. Older writers like Bishop Knud (1498) and Varwich (1577) note the occurrence of flies in large numbers in plague times. Mercurialis (1577) definitely referred to house-flies as carriers of the plague from the fact that they contaminated food upon which they settled after abandoning plague patients. Lange (1791) also regarded flies as carriers “ humoribus pestiferorum ” from the dead to the living. Haeser (1882) refers to Bengasi, Tripolis, in connection with a plague epidemic, in 1858, as being known to the Turks by the name of the “ Kingdom of Flies.” Turning to more recent times it may be noted that Yebsin (1894) in Hong Kong observed many dead flies lying about in his laboratory when he made autopsies on plague animals. He demonstrated by inoculation into animals that a dead fly contained virulent plague bacilli. Nuttall (1897), experimenting with M. domestica fed them on organs of animals dead of plague. He found that flies might survive eight days at 12-14°C. after feeding on infected organs and that they still harboured virulent bacilli 48 hours or more after they were transferred to clean vessels. At higher temperatures, 14°C. and upwards, the infected flies died more rapidly than did control flies which were fed on the organs of healthy animals. Nuttall concluded that the plague bacillus may be fatal to house-flies under suitable conditions of temperature. Matignon (1898, p. 237) observed that flies died in large numbers in Mongolia during plague times.