Further reports (no. 5) on flies as carriers of infection.

Date:
1912
Catalogue details

Licence: In copyright

Credit: Further reports (no. 5) on flies as carriers of infection. Source: Wellcome Collection.

    24/30 (page 20)
    *■ ^ t was not until the autumn that the larva3 were observed. They were expelled repeatedly in large numbers, and their expulsion in this manner continued for several months. The larvse were about equal in size and extremely active on their appearance. The malady did not recur and the evacuation of the larvae ceased shortly; the patient’s health gradually improved, but not com- pletely. The author calls attention to the fact that the symptoms made their appearance in the spring but the larvae were not expelled until the summer and autumn following. It would appear, therefore, that they entered the stomach in the egg state and after hatching passed into the intestine where they completed their growth. In 1876 Judd describes the discharge of the larvae of F. scalaris from the intestine of a boy in Kentucky, U.S.A. Stephens (1905) records the larvae of F. canicularis as having been passed per rectum. Cattle (1906) refers to a case in which large quantities of Fannia larvae occurred in the intestine, there were few symptoms and the larvae were being discharged per anum seven months after he first saw the patient. The writer (1909) has also recorded the occurrence of F. canicularis in the stools. Kecently, Saltan (1910) has recorded the occurrence at Plymouth on the 28th of Mav of the larva of F. canicularis in the stools of a man who had no previous intestinal pains. The occurrence in September, 1909, in the faeces of a hoy aged 12 of the larvae of a species of Fannia has been described by Garrod (1910). Occurrence in the Urinary Tract. It would appear most unlikely that the larvae of these insects should be discharged from the urinary tract and yet there are a number of records of such occurrences. These have been excellently summarised by Chevrel (1909), who, in addition, reports a case of the occurrence of the larva of F. canicularis in a woman of 55 who suffered from albuminuria and urinated with much difficulty. Eventually, thirty to forty larvae of F. canicularis of different sizes were passed from the urethra. Method of Infection. The larvae of the Hies belonging to the genus Fannia inhabit, as has been, seen from the preceding account of their breeding habits, excrement and decaying vegetable products and the female flies, guided by their sense of smell and impelled by their maternal instincts, seek such substances. They are attracted to excrement, decaying, putrefying or purulent substances. These facts render several methods of infection possible. In the case of intestinal myiasis, the flies may have deposited their eggs in rotting or decaying fruit, vegetables or other food which may be eaten in a raw state and thus the eggs or young larvce will be taken into the digestive tract; or, the flies, which are generally to be found depositing their eggs in the old style privies, may deposit their eggs in or near the anus, especially if the person is somewhat costive. The larva', on hatching, make