Part 2

It appears to me not improbable that this specimen may be found to supply what has hitherto been a missing link, namely, the male animal.

Since writing this I have had the opportunity of submitting the specimen to Dr. Munson, who at once recognised it as the male worm, and has undertaken to make a careful microscopical examination and description of it.

“Report by DR. MANSON on the structure of the Filaria loa, from an examination of the specimen removed in the foregoing case, as well as of the specimen of the same parasite exhibited at a meeting of the Society on January 31st, 1895. The latter filaria was removed from the eyelid of a patient by Dr. J. R. Logan, Liverpool.—

Male. Nat. size.]

Male. × 6.]

Head of male.]

Tail of male. Dr. Logan’s.]

Tail of male. Dr. A. Robertson’s.]

Filaria loa: male.—Body filiform, cylindrical, measuring from 25 mm. to 30 mm. in length, by 0·30 mm. in breadth, of uniform thickness, except where it tapers at the head and tail. The cephalic end tapers somewhat abruptly to the simple mouth, which is destitute of papillæ and armature. There is no distinctly marked neck, but there is a sort of shoulder about 0·15 mm. behind the mouth, where a number of strong muscular longitudinal bands originate to pass down the body. In one of the specimens the extreme head end is retracted and abruptly truncated, measuring at the free end 0·1 mm. across; in the other worm this part is more conical, and in it a short pharynx can be seen, which opens out somewhat posteriorly. At 0·1 mm. from the mouth the diameter of the worms is 0·15 mm.; further back, at 0·6 mm. from the month, it is 0·25 mm. The tail end is sharply incurvated and, perhaps, excavated ventrally; it is not spirally twisted. The tail is provided with well-marked lateral alæ, which can be traced forwards to a point 0·3 mm. from the tip of the tail. At the base of the anterior papilla the tail is 0·08 mm. in diameter. There are five well-marked papillæ on each side of the ventral surface of the tail. The three anterior papillæ are præanal and very large, the most anterior being the largest. The papillæ are closely approximated, stout, and bulbous at the free end; they measure 0·04 mm. in length by 0·022 mm. in breadth. The fourth papilla appears to be adanal or post-anal, and is rather more separated from the third than the three anterior papillæ are from each other, and is distinctly nearer the middle line; it is also considerably smaller, 0·03 mm. by 0·01 mm. The fifth and most posterior papilla is very much smaller than the others and differently shaped, being conical and sharp-pointed. It measures 0·014 mm. in length by 0·005 mm. in breadth at this base. There are two slender and unequal spicules projecting from one of the specimens. The cuticle is not obviously striated, but is dotted over with a number of widely scattered, nearly hemispherical, smooth bosses, springing abruptly from the surface. There appears to be no definite arrangement of these bosses; at all events, if they are arranged after a pattern this could not be discerned. The larger bosses are found towards the middle of the parasite; at the head and tail they are considerably smaller, and in these situations they are more sparingly distributed. The larger measure at the base 0·12 mm., and rise about 0·004 mm. above the general surface. The extreme ends of the parasite are not provided with bosses, the first met with being about 1·5 mm. from the mouth and tail-tip respectively.

“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.”

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.

2. Mrs. H⸺, the widow of a medical missionary to Old Calabar. I had the opportunity of seeing this lady, and eliciting the following particulars.

She was three years in Old Calabar, from 1860 to 1863, at Old Town Station. Here the water-supply was obtained from a spring which emerged from the ground at a little distance from the river. Before use for drinking the water was filtered through a porous stone basin, but it was not boiled. The water for washing was not boiled or filtered, nor were any precautions taken to prevent it coming in contact with the eyes. During part of the time she was at Old Calabar she suffered from worm in the eye, sometimes one, sometimes the other was affected, but never both at the same time. She occasionally had a feeling as if the worm were making its way under the skin at the root of the nose, in the eyelids, or on the temple. The left eye was the one chiefly affected. She was invalided home on account of intermittent fever. She did not suffer from dysentery. The worms troubled her occasionally after her return home, but they never came to the surface at a convenient time for removal till in 1875, when her husband, Dr. H⸺, succeeded in removing a worm from her left eye. She could not now recall the steps of the operation. About a year later another worm was similarly removed by her husband—she thinks from the same eye, and since then she has not experienced any symptoms of filaria. These worms were preserved in spirits, but she fears were, after some years, thrown away.

As in the case of my patient, Mrs. H⸺ noticed that the worms scarcely troubled her at all during winter. It was only in warm weather they were lively. Both ladies occasionally noticed that the worm lay for a short time coiled up and motionless under the conjunctiva. When the worm appeared on the surface Mrs. H⸺ experienced a “biting, nibbling sensation” at the part where the worm was, and the eye became tender and watery, so that she had to keep it closed, but it never produced any severe inflammation. When not under the conjunctiva or skin she was not aware of its presence.

3. The Rev. J. L⸺ went to Calabar in October, 1868, and returned in July, 1872. He often suffered from intermittent fever, on account of which he was invalided, and by medical advice did not return. His recollection of the time and circumstances of the appearance of the worm is now somewhat faint, but he thinks it appeared during the latter part of his residence in Old Calabar, and certainly troubled him after his return home. As far as he remembers, one eye only, and he thinks the right, was affected, but he cannot say with certainty. It only caused slight irritation, and no severe inflammation. It affected the eyelids, he thinks, more than the eye. He recalls one time in particular when, after preaching at Musselburgh, he felt it wriggling under the skin of the upper lid, and directed the attention of some friends to it, and they saw the movement of the worm. The intervals at which it appeared were irregular, but generally pretty long. He never felt the worm in any other part of the body. As far as he can remember, the visits of the worm to the eye or lids did not generally last long—at most two days. No attempt was made to extract it, nor did any doctor see it. He has seen or felt nothing of the worm for the last eight or nine years, at any rate. He did not notice that the worm was influenced in its visits by the external temperature.

In addition to these cases among members of the Old Calabar Mission, I may refer to the experience of Dr. Thompstone, who was for eighteen months stationed at Opobo, on the delta of the Niger, and who is in this country at present. He informs me that while he was at Opobo he saw two cases of Filaria loa. In the one negro the parasite was situated in the lower eyelid at the inner canthus close to the lachrymal sac—the swelling in that region giving the appearance of dacryocystitis. He tried to press out what he considered the contents of the distended sac, when he observed the coiled-up worm to wriggle away into the orbit, and the swelling disappeared.

In the other negro he observed the worm moving about under the conjunctiva when he depressed the lower lid. The patient was affected with slight conjunctivitis. Dr. Thompstone wished to undertake the extraction of the parasite, but the patient declined operative interference. While at Opobo he neither saw nor heard of other cases of the affection. The water-supply for the native population there was very polluted.

The literature on this subject is very scanty. As far as I have been able to ascertain there have hitherto not been more than twenty cases recorded, and in most of them the accounts given have been bald and short in the extreme. I may, therefore, be permitted to give a short résumé of what has been written regarding this filaria.

The first case recorded appears to be that observed by M. Bajon, a French surgeon, who for twelve years practised his profession in the island of Cayenne and in Guiana. He reports that in July, 1768, the captain of a ship from Guadalupe brought to him a young negress about six or seven years of age, and asked him to examine one of her eyes, in which a small worm, about the thickness of a fine sewing thread, could be distinctly seen. It was about two inches in length. It cruised round about the eyeball in the cellular tissue between the conjunctiva and sclerotic. It moved in a tortuous oblique manner. The colour of the eye was not changed, and the young negress said she felt no pain with the movements of the worm, but she had an almost continual watering of the eye.

On reflecting on the means he should employ to draw it out, he concluded that if he made a minute aperture in the conjunctiva close to the head of the small animal, and then stimulated it to move, it would emerge through the opening. In carrying out this manœuvre, however, he found that in place of escaping through the incision he had made, it passed by the side of it, and went to the opposite surface of the eye. As this proceeding did not succeed with him, he had recourse to the device of seizing the worm by the middle with small forceps, along with the conjunctiva, then making a small deep opening with a lancet by the side of its body, and then introducing an ordinary needle, whereby he succeeded in drawing it out doubled in two.

Again, in 1771, another young negress, a little older than the last, was brought to M. Bajon suffering from painful inflammation of the conjunctiva. On examination he observed a worm a little longer than in the previous case, and which, like it, moved round about the eye between the conjunctiva and sclerotic. He proposed to employ the same procedure that succeeded in the other case, but the patient would not consent.

He considered that the worm was a dracunculus (dragonneau) similar to those removed from other parts of the body in negroes, only finer and shorter.