Schlesinger and Weichselbaum’s case shows that there are forms of myiasis intestinalis which, after prolonged sickness, lead to death, and that in consequence of the formation of intestinal abscesses stricture of the intestine may arise from the subsequent formation of a scar.
The question of the mode of infection is interesting; in this mouth, nose and anus must be considered. The most frequent way is certainly by means of food on which flies have laid their eggs, or which is permeated with young maggots. This may be raw (especially grated) meat, cheese, fruit, salad, milk, cabbage, cold farinaceous foods, raspberries. When the stomach is affected, when the gastric juice has lost acidity and power of digestion, the larvæ will be able to stay and develop more easily. According to Csokor,[1201] if the eggs get into the gastro-intestinal canal of man with the food, the delicate stages of the young larvæ would certainly not survive the action of the gastric juice. Salzmann[1202] assumed that the invasion occasionally occurred through the rectum, the larvæ creeping into the anus while the person is asleep. Wirsing accepts this method of infection for two of his cases, where it was a question of the infection of an infant. Salzmann[1202] reports a case where the maggots of Anthomyia[1203] scalaris were passed in great numbers from the urethra of an old man. The patient had been catheterized on account of urethral stricture and was probably infected with eggs or larvæ at the same time.
The diagnosis of the affection is easy and sure, if living larvæ are found in the contents of the stomach or in the stools, and if contamination is out of the question.
The number of different species of flies whose larvæ are found in myiasis intestinalis is considerable. The larvæ of species of Anthomyia (A. canicularis,[1204] A. scalaris, etc.), of Sarcophaga carnaria and S. magnifica and of Musca vomitoria[1205] are especially observed.
The prognosis is certainly generally favourable, but must be made with some reserve in chronic cases, in view of the observations of Schlesinger and Weichselbaum (intestinal stenosis).
The treatment must aim at removing the larvæ as soon as possible from the digestive canal.
In cases of myiasis of the stomach, a thorough washing out of the stomach (Joseph,[1206] Staniek[1207]) is to be preferred to emetics used with success in individual instances; perhaps it would be advisable to add menthol or thymol to the mixture.
In myiasis of the intestine internal remedies and local treatment of the intestine must be considered.
So far santonin seems to have proved to be the best remedy. In some cases extract. filicis maris, calomel, semina cucurbitæ, naphthalene 0·1 to 0·5 (Peiper[1208]), infus. of Persian insect powder (5 in 200), mineral waters, Carlsbad water, seem to have had good results.
For irrigation of the rectum, weak solutions of argentum nitricum, tannin, thymol, gelatine, ol. ricini, naphthalene may be used. Wirsing administered an aperient (Rurella compound liquorice powder) and a soap enema after the passing of the first larvæ.