Case of Filaria loa

by Douglas Argyll Robertson

“Owing to the opacity of the specimens the details of the internal structure cannot be made out. In one worm, as mentioned, a short pharynx can be seen, but its continuation into the œsophagus cannot be traced. The prolapsed testicular and alimentary tubes in one of the specimens are collapsed and ribbon-like; they are about 0·09 mm. in breadth.

“The following diagram roughly indicates what I conceive to be the arrangement of the details of the under surface of the tail.”

Fig. 6.

Diagrammatic.

In endeavouring to ascertain how the parasite entered the system I inquired as to the water and food supply at Old Calabar, and my patient informed me that at Iköröfiön, the mission station at which she resided, the entire water-supply during the dry season was obtained from a spring that bubbled up out of the ground close to the river. During the rains, however, this spring might occasionally be covered by the swollen river, but at that season the water-supply was derived from a tank in which the rain was collected. The water used for drinking was always boiled, and twice filtered. In washing her face she was specially careful to keep her eyes well closed, and if at any time her eyes were sore she bathed them with the drinking-water. These precautions she took, as it was a popular belief among the natives that the worm gets access to the eyes through the water with which the eyes are bathed. She further informed me that the occurrence of this kind of worm in the eye is well known to natives of Old Calabar, and they use a solution of salt and water as a wash to scare them away. Mosquitos abounded at the station, and any water left standing in a dish soon swarmed with their eggs. The fruit supply consisted of mangos, Avocado pears, bananas, pineapples, oranges, and custard-apples. No uncooked vegetables were used as food.

She herself had seen a number of instances of the worm in the eyes of natives, and thus knew the nature of the affection when she had it herself. It is said in Calabar that they are very difficult to capture. She has never heard of the parasite piercing the skin or conjunctiva.

The ordinary guinea-worm (Filaria medinesis) under the skin is unknown in Old Calabar. Miss H⸺ acted as dispenser for about a year during the missionary’s absence, and never saw a case of it, nor heard of it occurring during the whole of her residence there.

As a result of inquiry I found that other members of the Old Calabar Mission had been affected with Filaria loa.

1. A lady, Mrs. M⸺, who for a time had resided with my patient at Iköröfiön. She was in this country this year, but has returned to Old Calabar. While in Scotland the worm was seen in her eye by my patient Miss H⸺ and her sister, who is at present engaged in the study of medicine. The latter saw the worm pass from the one eye to the other, crossing the bridge of the nose under the skin.