CHAPTER XXII

FILARIAL INFECTIONS

GENERAL CONSIDERATIONS

The filarial worms are thread-like nematodes, with a thin cylindrical oesophagus, which live in various parts of the body and may or may not give rise to disease conditions. It is one of the most remarkable facts in animal parasitology that a person may harbor numerous adult filariae and myriads of embryos without in any way manifesting symptoms of the infection. In most of the filarial worms the female has a double uterus with the uterine opening near the anterior extremity.

[Illustration: FIG. 94.—Geographical distribution of Filariasis.]

It has been proposed to designate the filarial embryo by the term microfilaria, reserving the generic name _Filaria_ for the adult parasite. This may be convenient for differentiation but zoölogical nomenclature does not permit different names for adults and embryos. While there have been almost 20 different filarial species reported for man there is, in some instances, doubt as to the correctness of the observation, and again, a well recognized species has at times been considered as a new species and given a new name.

From a practical standpoint we need only consider: (1) _Filaria bancrofti_; the adult of which lives in the lymphatic glands and vessels while the sheathed embryos (which from their appearance in the blood only at night are called _Filaria nocturna_) obtain access to the peripheral blood vessels.

[Illustration: FIG. 95.—1a, Adult female Guinea worm (_Dracunculus medinensis_) showing anchoring hook at posterior extremity. 1b, Cross section of female _Dracunculus_ showing uterus filled with embryos. 1c, Striated embryos of the Guinea worm. 1d, _Cyclops coronatus_, the minute crustacean which serves as the intermediate host of _D. medinensis_. 2a-2d, Anterior and posterior extremities of _L. loa_. 2c, Section showing tuberculated cuticle. 2b, Male and female _L. loa_, natural size. 3a, Bulbous anterior extremity, _Filaria bancrofti_. 3b, Tail of male. 3c, Tail of female. 3d, Male and female, natural size of _F. bancrofti_. 4a, Tumor mass of _O. volvulus_ laid open. 5, Mosquito showing filarial embryos in thoracic muscles (a) and in labium (b). The labella which are separated from the labium by Dutton’s membrane are seen at (c). 6(a) Embryo of _F. bancrofti_. (b) Embryo of _L. loa_ showing filling of tail end with cells. 7, Microfilaria of _F. bancrofti_ in blood. Dotted lines show location of break in cell column and V spot.]

Various well-known conditions are caused by this parasite, such as elephantiasis, varicose groin glands, chyluria, etc. This infection was formerly stated to be caused by _Filaria sanguinis hominis_.

(2) _Loa loa_, the adult of which wanders about in the subcutaneous tissues, characteristically in the region of the eyes, while the sheathed embryo is found in the blood during the day, hence _Filaria diurna_.

Calabar swellings, irregular febrile conditions and the disagreeable sensations incident to the wanderings of the worm are clinical features of this infection.

-----------+--------------------+--------------------+------------------- | Adults | Embryos | Remarks -----------+--------------------+--------------------+------------------- |Male 40 by 0.1 mm. |Sheathed, 300 by 7.5|Transmitted by | Female 90 by 0.28 | microns. Distance | mosquitoes, Culex | mm. Smooth cuticle.| from head to V spot| fatigans and Filaria | Bulbous anterior | 90 microns; to | Stegomyia pseudo- bancrofti | extremity. | break in cells 50 | scutellaris. | Occupy lymphatic | microns. Tail | Causes | glands and vessels.| rather straight. | elephantiasis, | | Terminal cells do | lymph scrotum, | | not fill up tail | chyluria, etc. | | end. Nocturnal | | | periodicity in | | | peripheral | | | circulation. | -----------+--------------------+--------------------+------------------- |Male 27 by 0.3 mm. |Sheathed, 240 × 7 |Transmitted by | Female 55 by 0.4 | microns. Distance |species of a biting | mm. Cuticle tuber- | from head to V spot| fly—Chrysops. | culated. Anterior | 65 microns; to | Causes calabar Loa loa | extremity like | break in cells | swellings. Worms | truncated cone. | 40 microns. Cork- | often visit ocular | Wanders in | screw tail which is| region. | subcutaneous | completely filled | | tissues. | up with terminal | | | cells. Diurnal | | | periodicity in | | | peripheral | | | circulation. | -----------+--------------------+--------------------+------------------- |Male 40 by 0.07 mm. |Without sheaths, 200|Transmitting agent | Female 75 by 0.1 | by 5 microns. Post-| not surely known. | mm. Cuticle smooth.| erior two-thirds | Mosquitoes and Acanthoch- | Tip of tail shows 2| tapers to blunt | ticks suggested. eilonema | triangular | ending. Distance | No pathogenicity. perstans | processes. Found | from head to V spot| | about root of | 49 microns; to | | mesentery. | break in cells 34 | | | microns. Persists | | | in circulation both| | | day and night. | -----------+--------------------+--------------------+------------------- |Male 30 by 0.14 mm. |Without sheaths, 250|Method of trans- | Female usually | by 7.5 microns. | mission unknown. Onchocerca | fragmented. | Found in cyst-like | Causes small volvulus | Possibly 75 by 0.36| spaces of tumors. | cystic tumors, | mm. Cuticle | Not in peripheral | under skin of | striated. Found | circulation. | thorax | coiled up in | | especially. | cyst-like tumors | | | under skin. | | -----------+--------------------+--------------------+------------------- |Male from Leiper’s |Without sheaths. 600|Embryos swallowed | monkey 22 mm. | × 20 microns. Long | by Cyclops. Man | Female 80 to 90 cm.| slender tail. | drinks water | long by 1.6 mm. | Cuticle striated. | containing Dracunculus| wide. Smooth white | Extruded from break| Cyclops. medinensis| body. Anchoring | in skin of patient.| | hook at tail end. | | | Female lives in | | | subcutaneous | | | tissue of lower | | | extremity. | | -----------+--------------------+--------------------+-------------------

(3) _Onchocerca volvulus._ The males and females of this parasite are found coiled up in channeled connective tissue tumors of the subcutaneous tissues.

The sheathless embryos have been surely found only within these tumors and not in the blood.

(4) _Acanthocheilonema perstans._ This parasite does not seem to give rise to clinical manifestations except possibly to cause an irregular fever.

The adult is found in the retroperitoneal connective tissue or fat, while the sheathless, blunt-tailed embryo is found in the blood, both by day and night, hence _perstans_. The adult forms are found in the tissues behind the abdominal aorta and at the attachment of the mesentery.

(5) _Dracunculus medinensis._ The female of this parasite, about 36 inches long and 1/15 inch in diameter, travels to the subcutaneous tissues of the extremities and boring through the skin causes a small surface erosion.

An unimportant filarial worm which has been found only in the West Indies and British Guiana is known as _Filaria demarquayi_ or _F. ozzardi_. The embryos have sharp tails and are without a sheath. The parasite is not known to produce symptoms.

HISTORY

_Filaria bancrofti._—While elephantiasis was frequently described by ancient writers yet the confusion between Elephantiasis Graecorum, a term applied to leprosy, and Elephantiasis Arabum, or the filarial condition, made the question of the nature of the skin thickenings very indefinite.

The thickenings due to leprosy and those connected with filariasis were separated clinically by observers during the 17th and 18th centuries, Hilary, in 1750, having accurately described the progress of that form of elephantiasis connected with elephantoid fever and lymphangitis. In 1863 Demarquay discovered filarial embryos in the exudate of a chylous hydrocele and three years later Wucherer, in Brazil, found similar nematode larvae in the urine of a case of haematochyluria. Commencing with the year 1863 Lewis carried on a series of investigations in Calcutta in which he found these embryos not only in the urine of patients with chyluria but as well in the lymph and blood of those affected with elephantiasis. He called the parasite _Filaria sanguinis hominis_, a name still frequently employed by medical writers.

In 1876 Bancroft, in Australia, discovered the adult filarial worms in a lymphatic abscess, hence the name _Filaria bancrofti_. In 1878 Manson, in China, demonstrated the mosquito transmission of the disease as well as the phenomenon of nocturnal periodicity. Manson’s idea, however, was that the fully developed embryo escaped from the body of the infected mosquito at the time of the death of the insect and that man contracted the infection in drinking water.

The investigations of Low and more recently those of Fülleborn and Bahr and others have shown that the larvae escape by way of the mosquito’s proboscis and enter the skin of man.

_Loa loa._—The knowledge of a filarial infection of the region of the eye seems to date from the time of Magellan. Although the disease is now confined to the west coast of Africa, cases were reported from the West Indies by Mongin and Bajou during the 18th century. These cases were in slaves who had contracted the infection in Africa.

[Illustration: FIG. 96.—Section of _Stegomyia pseudoscutellaris_, showing filariae in thorax on tenth day of development, travelling forwards into proboscis. By permission from Manson’s Tropical Diseases.]

In 1891 Manson noted the presence of the larval forms which showed a diurnal periodicity in the peripheral blood.

_Dracunculus medinensis._—Ancient Egyptian writings would indicate that the disease was well known in those times. It is believed that the fiery serpent of the wilderness, which afflicted the Children of Israel, was an infection of this sort.

The prevalence of dracontiasis, as the infection is generally termed, in Arabia, was well known to the Greeks and Romans.

Fedschenko, in 1870, noted the transmission of the disease by species of _Cyclops_.

_Onchocerca volvulus_ was first discovered in 1893, in peculiar tumors of the natives of the Gold Coast.

[Illustration: FIG. 97.—Female guinea worm (_Dracunculus medinensis_) lying under the skin of the forearm. By permission from Manson’s Tropical Diseases.]

_Acanthocheilonema perstans_ was first found by Manson, in 1891, in the blood of natives of the Congo.

Daniels also found these embryos, along with those of _F. demarquayi_, in the blood of natives of British Guiana.

FILARIA BANCROFTI

GEOGRAPHICAL DISTRIBUTION

This parasite has been found in almost all tropical and subtropical countries. It is quite prevalent in the West Indies and has been found in some of the Southern states of the U. S. It is very common in some of the South American countries as well as in Central America. The infection is widespread in Arabia, India and China. Africa, especially the West Coast, and Australia, particularly in Queensland, are parts of the world where the infection prevails.

It is especially in some of the Pacific islands, as Samoa and Fiji, that it is extraordinarily prevalent. Bahr has stated that Fijians in the proportion of 27% show filarial embryos in their blood. In 25% of these natives clinical manifestations of the disease exist but the embryos are absent from the peripheral circulation. In other words more than one-half of the population show absolute evidence of infection.

LIFE HISTORY

It is a well-known fact that filarial embryos may be present at night in the peripheral blood of persons not showing a single symptom of filariasis and again, in those with marked elephantiasis, varicose groin glands or chyluria there may be an entire and permanent absence of embryos in the blood. When certain mosquitoes bite persons having embryos in the blood they take into their stomachs the sheathed embryos of _F. bancrofti_. Flu states he has succeeded in infecting the following mosquitoes: _C. fatigans_, _S. scutellaris_, _M. ludlowi_ and _M. rossii_. The most suitable carriers proved to be _C. fatigans_ and _S. scutellaris_. Large numbers of larvae perish in anopheline mosquitoes.

The following developmental cycle has been demonstrated for _Culex fatigans_ and _Stegomyia pseudoscutellaris_. Bahr has found that if there are too many embryos taken up by the mosquito the insect is apt to die, as the result of too heavy an infection; so that a person harboring many filarial embryos may be less dangerous than one with a smaller number. Upon reaching the stomach of the mosquito the sheath of the embryo becomes fixed in the viscid blood contents and the embryo itself by active motions is able to force itself from its sheath. This escape usually occurs within two hours but may take longer. The free embryo then bores its way through the stomach walls and within twenty-four hours has reached the thoracic muscles of the mosquito. Within forty-eight hours the embryo begins to broaden and the anterior and posterior V spots to become more prominent. About the end of the first week there commences the formation of an alimentary canal, by which time the developing larva is about 0.5 mm. long. When the larva is about 0.6 mm. long an ecdysis apparently takes place. Later on these larvae develop 3 or 4 terminal papillae and make their way to the fleshy labium of the mosquito’s proboscis. An occasional larva may enter other structures than the labium but in such case they would be unable to effect an entrance to their definitive host, man. These larvae in the proboscis are about 1.5 mm. long and about 20 microns broad.

The mosquitoes have two terminal processes, the labella, separated from the labium by a thin membranous partition called Dutton’s membrane. The larvae, having completed their developmental cycle in the mosquito, which takes about three weeks, and moving down the labium, break through this membrane when it is put upon a stretch by the wide separation of the labella at the time of feeding on the part of the mosquito. It was formerly supposed that the larvae entered man through the puncture made by the biting parts of the mosquito, but Bahr has shown by experiments that they effect an entrance through the intact pores of the skin as does the ancylostome larva.

These larvae upon entering the human host reach the lymphatic vessels or glands and in this definitive host (man) the females are fertilized by the males and give off sheathed larvae from the uterine opening near the anterior end of the worm.

[Illustration: FIG. 98.—Male (a) and female (b) of _Filaria bancrofti_. Natural size. (From Greene after Manson.)]

The sheath is simply the egg membrane which from being oval at first becomes stretched by the developing embryo to finally become a long, narrow sac encasing the fully developed embryo as it exists in man. From the lymph stream they reach the general circulation. In a case of a man with filarial embryos in his peripheral circulation, who committed suicide one morning, Manson found the embryos, in large part, contained in the vessels of the lungs. There were 675 embryos per slide in blood from the lungs for one from blood from the spleen or liver. It would thus appear that during the day, when the embryos are absent from the peripheral circulation, they retire to the lungs. In the case of the filarial embryo of persons in the Pacific Islands there does not appear to exist any periodicity. Bahr thinks this absence of nocturnal periodicity to be connected with the habits of its principal intermediary host, _Stegomyia pseudoscutellaris_, which feeds by day. _Culex fatigans_ feeds at night.

With the filarial embryos found in patients in the Philippines there is also a lack of nocturnal periodicity. In the opinion of Ashburn and Craig the Philippine filarial worm is a new species, _Filaria philippinensis_.

Walker, however, recently examined four adult filarial worms in the Philippines and was unable to note any differences from _F. bancrofti_.

PATHOLOGY AND MORBID ANATOMY

The adult worms may exist in numbers and over long periods of time give off great numbers of embryos into the peripheral circulation without there being any evidence of disease in the patient. There is apt to be at such time a marked eosinophilia. The process by which the fibrosis of lymph channels with obstruction to the flow of lymph occurs is unknown. Some think that with the pouring out of embryos inflammatory processes, bacterial or otherwise, may be set up. We know that there is a tendency for these adults to die and become calcified, in this way bringing about lymphatic obstruction.

Bahr notes the influence of adult filariae in producing an increase in connective tissue in glands and considers such glands as less resistant to bacterial infection.

Manson has an idea that some factor may cause the female to give off immature embryos, which being oval, and of considerable width, may block the lymphatics.

It has often been claimed that various cocci were the exciting factors in the lymphangitis associated with filariasis. Recently Dutcher has reported the isolation of an organism resembling _B. subtilis_ as the cause of filarial lymphangitis (_Bacillus lymphangiticus_).

As the result of the lymphangitis and blocking of the channels the embryos cannot reach the peripheral circulation; hence when obstruction does occur and symptoms of lymph stasis appear, there may be an absence of embryos in the circulation.

It is now well established that patients with elephantiasis very rarely show embryos in the peripheral circulation, and this fact should be better understood because there is a tendency to negative a filarial diagnosis when embryos are absent from the peripheral circulation.

These lymph channel obstructions may at one time cause dilatations or varices and at another bring about solid oedemas of the tributary parts. The treatment will be considered under each special form of the disease. It may be stated however that salvarsan, arsenophenylglycin and other similar remedies have been without special effect in destroying the filarial worms.

CLINICAL MANIFESTATIONS

Not only is it important to understand that elephantiasis and other manifestations of filarial infection may and usually do exist without there being embryos in the peripheral blood of the patient, but also, that a high percentage of a population may show filarial embryos in their blood and yet never or with extreme rarity show any of the signs of filarial disease. These people, with abundant embryos in their blood, usually show no disturbance of health. In the Philippines one may rarely see a case of chylocele but usually there is nothing clinical to note.

Johnson, in examining 400 people, in Charleston, S. C., found 19% with filarial embryos, yet only 5% showed any symptoms of filariasis. Croll states that 11.5% of 4000 Europeans admitted to the Brisbane Hospital (Australia) showed filarial infection but practically none had symptoms. In South Queensland cases of lymphangitis, chyluria and varicose groin glands are occasionally seen and rather frequently hydrocele and filarial abscesses. There is an absence of elephantiasis.

Elephantoid Fever

The febrile accessions that accompany the recurring attacks of lymphangitis in elephantiasis, lymph scrotum and other filarial manifestations, are very important because they may lead to errors in diagnosis.

Thus in Barbadoes, where there is no malaria, a condition in which there occurs a high fever of sudden onset with rigors and associated erysipelatous redness of leg or scrotum, accompanied by lymphangitis and painful lymphatic glands, has given a suggestion of a malarial paroxysm. The tense inflamed area, after several days, shows an exudation of lymph and the redness disappears, but with some resulting thickening of the affected tissues. Such attacks may terminate with profuse sweating.

The treatment of the condition is such as would be advisable for ordinary lymphangitis—rest in bed, elevation of the part, laxatives and local applications.

Lymph Scrotum

This condition is apt to set in with fever. The scrotal tissues are somewhat tense and reddened and may show numerous lymphatic varices which when pricked with a needle, give exit to lymph which may or may not contain filarial embryos. The lymph continues to exude for a long time. Erysipelatous manifestations are not uncommon. With recurring attacks the scrotal tissues become more and more hypertrophied and may go on to elephantiasis of the scrotum.

Ordinarily local applications with suspension of the scrotum is the proper treatment. Should the thickening increase to a great extent the blubbery tissues may be excised, care being exercised to avoid the testicles and to bring together sound tissue for the enclosing flaps. These wounds usually heal readily, although there may be delay in healing from the outpouring of lymph in cases where the flaps include diseased tissue.

Varicose Groin Glands

Swellings which come on rather slowly and insidiously may involve the inguinal or femoral groups of glands of one or both sides. The epitrochlear glands may also be involved. The skin over the enlarged, rather doughy glands can be freely moved but the glands themselves are bound down to the deeper tissues. Elephantoid fever may set in associated with local manifestations of pain and redness.

If such glands are punctured with a hypodermic needle lymph, which may contain embryos, exudes. This test together with their slow disappearance on lying down and slow return on assuming the upright position should differentiate hernia. When the contents of a hernial sac are omental there is some difficulty in diagnosis. As a rule it is not advisable to interfere surgically in this filarial condition.

[Illustration: FIG. 99.—Varicose groin glands and elephantiasis of scrotum and penis. (From Ruge and zur Verth.)]

Filarial Abscesses

As a rule injury to the adult filarial worms, which results in their death, is not followed by abscess formation but such termination may occur. These abscesses have been found deeply seated in the extremities. Wise and Minett in a careful examination of 28 such cases found evidences of adult filariae in 22 cases. In 21 of these abscesses, infections with streptococci or staphylococci were demonstrated. Very interesting also is the finding of filarial worms in deep-seated abdominal abscesses.

As regards location, these filarial abscesses were found 31 times in the pelvis of the kidney, 18 times in the epididymis, 12 times in the retro-peritoneal tissues, 25 times in the inguinal glands, 4 times in the ilio-psoas muscles and 8 times in the lymphatic vessels.

They regard the endemic funiculitis to which attention has been directed by Castellani as simply a similar process involving the tissues about the spermatic cord. The treatment of filarial abscesses is similar to that of other abscesses.

Chyluria

As the result of obstruction of the lymphatic vessels varices may form in the bladder lymphatics and, as the result of their rupture, milky urine may be passed. If the thoracic duct be occluded the urine will show an abundance of fat, while if the obstruction exists only in other lymphatics, the milky fluid will be found to show but little fat. Blood is usually present in chyluria so that the urine will show an pinkish tinge.

Chylous urine coagulates rapidly and we have in such a specimen of urine, upon standing, an upper fatty layer and pinkish sediment at the bottom, with a clot between.

The sediment shows lymphocytes and at times filarial embryos. When the exudate is lymph mixed with blood the term haematolymphuria would be a better one.

Clots may form in the bladder and give rise to obstruction to the flow of urine from the bladder.

The appearance of the chyluria is often preceded by heaviness about the loins and pains in the region of the bladder.

The morning urine in such a case is apt to be clear while that passed later in the day is milky in appearance.

A feature of chyluria is its tendency to disappear and reappear so that when treating such a case one should be conservative in considering the treatment as effecting a cure.

It is difficult to understand why chyluria should be common in India and China while almost unknown in the filarial infections of the Pacific islands.

In treating a case of chyluria one should enjoin rest in bed, laxatives and a restriction of fluids and fats. Patients subject to the condition should refrain from active exercise and other conditions which might cause fatigue. Drugs are of little value.

Filarial Orchitis and Hydrocele

The condition rather resembles an attack of epididymitis. As a result of recurring attacks hydrocele develops. The fluid may be lymphous or chylous in appearance and upon microscopical examination may show filarial embryos. These filarial hydroceles seemed to be the most common manifestations of the disease as observed in the Philippines. These hydroceles or chyloceles do not become very large but may require tapping.

Elephantiasis

As the result of recurring attacks of lymphangitis the tissues of the affected part show the effects of lymphatic obstruction by an hypertrophy of the skin and subcutaneous tissues. It would seem that the combination of lymphatic obstruction and bacterial infection is necessary for the production of elephantiasis. The skin of a part affected with elephantiasis is rough and the hair scanty. In addition to the lymphoedema of the part there is a great increase in the connective tissue.

On account of the lymphatic stasis incision into the blubbery tissue causes the outpouring of much lymph.

Elephantiasis of the lower extremities is by far the most common situation, giving us probably 90% of such affections. In Fiji elephantiasis of the upper extremities is quite common.

Other favorite sites are the scrotum, vulva, breasts and penis. Rarely the scalp or areas about neck or trunk may show involvement.

[Illustration: FIG. 100.—Elephantiasis of the legs. (From Ruge and zur Verth.)]

Surgical treatment is the one usually followed. When an extremity becomes too much of a burden, amputation may be indicated. The employment of the method of lymphangioplasty, which consists in the introduction of silk threads into the subcutaneous tissues, to make a channel to the normal lymphatics, does not seem to have been attended with any degree of success or at any rate permanent results. These wounds tend to become infected and if this does not occur the new channels are speedily obliterated.

Castellani recommends the use of Merck’s fibrolysin in injections of from 2 to 4 cc. daily, for three to six months. After each injection the part is tightly bandaged with flannel or rubber bandages. The injections may either be made into the affected part or into the gluteal region. Massage prior to the bandaging may give better results. When the limb becomes smaller and the skin smoother, long strips of skin and subcutaneous tissue may be dissected out and the adjacent edges sutured.

In considering the advantages of operation in elephantiasis of the scrotum it is usually stated that the only question involved is the removal of a burdensome mass which in no way is a source of danger to the life of the patient. At the same time such patients are subject to attacks of elephantoid fever, a condition not without its dangers. There is one factor not usually brought forward and that is the remarkable effect of a successful operation on the mental state of the patient. This is well shown in the accompanying illustrations of the patient before and after operation. If sexual deficiencies are of so powerful an influence on persons of education how much greater must they weigh on an uneducated native with but few of the higher interests of life.

Prior to operation the patient should be kept in bed for a day or so to lessen the amount of fluid and to secure relaxation of tissues. Thorough scrubbing with soap and water the day of and the day before the operation and the use of alcohol as an antiseptic are important. Some prefer iodine.

[Illustration: FIG. 101.—Elephantiasis of the scrotum. Before operation. (Fauntleroy.)]

For the operation the lithotomy position is employed. An assistant supports the scrotal tumor wrapped in a sterile towel. Fauntleroy, whose method I give, does not recommend a tourniquet to the base of the tumor as in his opinion it assists but little in controlling haemorrhage and endangers asepsis. Haemostats answer better and as the vessels which give most trouble are deeply situated the elastic cord would not affect them. In some cases there is very little bleeding. The upper part of the pear-shaped tumor usually affords sufficient sound skin next the thighs for the flaps. As a rule the elephantoid tissue does not involve the upper 2 or 3 inches of the skin anteriorly, which is thus available to cover in the base of the penis. In addition to this covering for the penis we have a long prepuce which has been considerably stretched so that after removing all elephantoid tissue there is enough sound prepuce remaining to cover the distal 2 or 3 inches, so that usually there is sufficient sound skin for a 5-inch penis.

[Illustration: FIG. 102.—Elephantiasis of the scrotum. After operation. Note change in mental state. (Fauntleroy.)]

The flaps which are to cover the penis and testicles should be mapped out with shallow incisions and care must be exercised that only sound skin is included in these flaps. A horseshoe shaped incision is made commencing at the left side of the base of the tumor about 1 inch from the thigh and about at the level of the penis in health. The incision is carried downward and passes just below the opening of the penis on the tumor surface. A similar incision on the right side completes the horseshoe curve. Next a downward incision in the sound skin is made over the posterior surface of the tumor, thus encircling the base of the scrotum. The anterior horseshoe incision is now deepened to free the penis, care being taken not to injure the spermatic cord. Next the incisions are deepened laterally until the testicles are reached. The testicles are usually in the center of the tumor imbedded in a blubbery tissue from which they can be easily stripped. The remains of the gubernacula are then hooked up and cut close to the testicles. The tunicae vaginales are often thickened and contain fluid which has to be drawn off.

In 60% of Fauntleroy’s cases it was necessary to remove one testicle on account of extensive disease. One must also bear in mind the possibility of hernial complications and undescended testicle.

A sound is now introduced into the urethra and the septum of the scrotum divided close to the sheath of the penis, then dissecting away the blubbery tissue. At this stage there may be considerable bleeding.

The testicles and spermatic cords are then dissected away from the tunicae vaginales. The penis is now freed by a circular incision around and above the opening in the anterior part of the mass. The remainder of the horseshoe flap is now dissected up and the penis freed. The proximal covering for the penis is made from this horseshoe flap which is stitched to the distal one shaped from the prepuce, carefully trimmed of elephantoid tissue.

The lateral flaps are brought together with linen or silk-worm gut sutures leaving space for a drainage tube and we thus form a new scrotum for the testicles.

The mortality is usually given as 5% but Fauntleroy did not lose a case among 149 such operations, the tumors varying from 10 to 85 pounds in weight.

Chylous Hydrocele

Filarial affections of the tunica vaginalis or the testicle itself are not rare. In the milky fluid obtained by tapping such a hydrocele we may find filarial embryos.

Besides chylous hydrocele we may have a chylous ascites or a chylous diarrhoea. Where there is no obstruction to the thoracic duct there is less fat and the condition is more properly a lymphocele rather than a chylocele. The same distinction is applicable to the other conditions connected with lymphatic varices due to lymphatic obstructions other than that of the thoracic duct.

LABORATORY DIAGNOSIS

The blood from a needle prick of the finger tip or the lobe of the ear can be examined as a fresh preparation. It is advisable to make a vaseline ring around the drop of blood on the slide and then apply a cover-glass. Such a preparation will permit of the examination of the living embryos for a day or more.

Smear preparations may be made by the Ehrlich method of drawing cover glasses apart or by the Daniels method on slides. Some prefer making a thick smear of a drop of blood and, after it has dried, carefully to dehaemoglobinize it with water and then staining with dilute haemotoxylin. Staining with Leishman’s or Wright’s stain gives beautiful pictures. Fixation with methyl alcohol or with heat, by burning off a film of alcohol, and then staining with Giemsa’s stain or some haematoxylin preparation, is to be recommended. On the whole I consider haematoxylin the most desirable staining reagent, as such preparations hold their color for a long time. The paper-like sheaths are seen as if twisted about the larvae with their violet-stained cells. One should note a break in the violet-stained cell column which is 50µ from the head end of _F. bancrofti_ and 40µ for _L. loa_.

A V spot is seen posterior to the break in the cell column and shows best with very light staining.

The break in the column of the cell nuclei marks the position of the nerve ring, which is distant from the head one-fifth the total length. The anterior spot, below the break in the cell column, is distant about 30% of the total length. It is the location of the excretory pore. In _F. bancrofti_ the cell nuclei extend to 95% of length, thus differing from those of _L. loa_, which fill up the tail end. At about 82% of the length from the head is located the anal pore.

Ruge’s thick film method for malarial parasites gives excellent results in staining filarial embryos. Either the Giemsa or haemotoxylin staining may be employed.

Embryos may be found in the lymph from varicose groin glands or in the exudate from a chylous hydrocele, as well as in the urinary sediment from a case of chyluria.

The failure to find embryos in no way negatives the existence of a filarial infection.

Adult filariae, either alive or dead and calcified, may be found in the lymphatic glands or in the contents of filarial abscesses.

The blood shows an eosinophilia.

LOA LOA

This filarial infection is at present only known for the West Coast of Africa. In the Cameroons and in Old Calabar the infection is quite common.

As noted in the table previously given, the adults which are a little more than an inch long have cuticular protuberances or bosses, about 12 to 15 microns in height. The sheathed embryo is very similar to that of _F. bancrofti_, but has a more twisted tail and shows a complete filling up of the tail end with rather elongated cells. The lines of the curves of the embryo show irregularities and are not the smooth lines characteristic of _F. bancrofti_ embryos.

The periodicity is diurnal, for which reason the parasite was originally termed _F. diurna_.

Leiper has reported two species of _Chrysops_, one of the tabanid biting flies, as transmitting agents and considers that the embryos undergo development in the salivary glands of the fly.

The life history is not well understood but as a rule a period of several years elapses after infection before adult filariae or filarial embryos are found. Again, for some reason, adult filariae may be noted and when extracted be found full of embryos and yet embryos not be found in the peripheral circulation.

The adults are noted for their tendency to move about in the subcutaneous connective tissues having been found in such tissues in the region of scalp, trunk, penis and extremities.

Most frequently, however, they are noted in the tissues about the region of the eyes and even under the conjunctivae, from which location they have been frequently extracted. It is this which has caused the name _Filaria oculi_ to be given the worm.

[Illustration: FIG. 103.—_L. loa_ above. _Acanthocheilonema perstans_ below. (From Greene, after Fülleborn.)]

The course of the wandering worm is usually marked by an oedematous track. In his own case, recently reported by a medical man, the first symptoms were transient painless swellings about the joints, associated with stiffness. Various diagnoses, such as rheumatism, erythema nodosum and angioneurotic oedema were made in his case. Although two adult filariae were removed at different times the blood examinations were negative for embryos.

As a rule the appearance of the worms in the subcutaneous tissues is characterized by itching sensations and a feeling of tension. Warmth causes them to appear in the superficial tissues while cold makes them confine themselves to the deeper structures. Eosinophilia is rather pronounced.

=Calabar Swellings.=—Although we have no absolute proof that these usually painless swellings, which occur rather suddenly on various parts of the body having only a thin layer of connective tissue, as forearms, face, ankles, hands, are connected with an infection with _L. loa_, yet such is the general view. These swellings are about the size of a hen’s egg, do not pit on pressure and last for about three days. There is marked tension over the swellings and they may itch greatly.

[Illustration: FIG. 104.—_L. loa_ in the subcutaneous tissues, twice normal size. (From Greene, after Fülleborn.)]

Rarely does one note more than one swelling at a time. Eosinophilia is quite marked during the attacks. Manson thinks the oedema results from the extrusion of embryos from the female at the site of the swelling. Ward considers the cause to be toxic material excreted by the worm.

There is very little of importance in connection with treatment. When the worms, which travel in the tissues about the eye, at the rate of about ½ inch per minute, are noted, some local anaesthetic may be used and the worm seized with forceps and extracted through a small incision. Elliot recommends the application of hot fomentations to the eye and upon the appearance of the worm under the conjunctiva to instill cocaine solution, seize the worm with forceps and then pass a silk ligature through the conjunctival fold taking in the worm. The ligature is tied and an incision made through which the worm is extracted. Cooling local applications, or an ichthyol ointment, may be applied to the Calabar swellings.

ONCHOCERCA VOLVULUS

This name is given to a filarial worm, found principally on the West Coast of Africa, which causes the formation of subcutaneous tumors. In certain localities as many as 10% of the population may be infected. More recently the parasite has been reported from Guatemala.

It is supposed that the adult worms cause an inflammation of the lymphatic vessel in which they may lie and that a formation of new connective tissue results, giving rise to a tumor-like mass, which is most often found in the axilla or about the sides of the thorax. This tissue stroma encompasses the worms except for the anterior extremity of the female, with its uterine opening, and the posterior extremity of the male carrying the spicules, which ends lie loose in a sort of cyst-like dilatation, which is filled with a viscid fluid swarming with unsheathed embryos. These tumor-like masses cause very little discomfort, last indefinitely and do not tend to ulcerate.

It was formerly thought that these larvae were absent from the peripheral circulation but more recent investigations in cases of onchocerciasis have shown sheathless larvae in the blood, which had the characteristics of those in the contents of the tumors. Such findings, however, are of extreme rarity, the blood examination being almost invariably negative.

The cysts are usually found on the sides of the chest and are quite superficial, with the skin freely movable over them. They may be as large as a hen’s egg but usually are smaller. They are also found over trochanters or along the crests of the ilium.

Dubois states that the embryos may be found in juice from puncture of groin glands.

The tumors are easily enucleated.

In the American infections the tumours are more common in the regions near the eye and it has been thought that certain cases of keratitis may be due to onchocerciasis.

DRACUNCULUS MEDINENSIS

The disease caused by infection with this parasite is usually termed dracontiasis and the parasite _Dracunculus medinensis_ or the Guinea worm.

The geographical distribution includes India, Arabia, the West Coast of Africa and Brazil.

_Life History._—The male has not surely been seen in man so that the pathological condition is entirely connected with the female worm. Almost invariably the female worm, which measures about two feet long by 1/12 inch broad, tends to wander down to the connective tissue structures of the lower extremity. In about 10% of the cases the worm may present elsewhere, as scrotum, back or arms. At the posterior extremity there is a sort of anchoring hook.

With the anterior extremity the worm presses against the overlying skin and causes the formation of a blister-like lesion.

This vesicle later on bursts and, if water is applied to the spot, a delicate tube, the uterus, is extruded and there exude a few drops of a milky fluid, which swarms with the sharp-tailed, striated, sheathless embryos. It is thought that the pouring forth of embryos, when water touches the part, is in order that the embryos may reach the water of a pool through which the infected native may be wading. Once in the water of such a pool, the larvae are swallowed by _Cyclops_ and gaining the body cavity of this little crustacean, they continue to develop for about one month.

During this period there are two ecdyses, the first after about two weeks, when the tail becomes blunt.

When one takes these infected cyclops into the stomach, by drinking water containing them, the cyclops is killed by the gastric juice and the Guinea worm larva breaks out of the dead intermediary host and bores its way through the stomach wall and possibly goes to the tissues about the retroperitoneal region. As a matter of fact we are in ignorance of the exact cycle which goes on, until the fertilized female, with her embryo-distended uterine tube, reaches the lower extremity. A cross section of the female shows the body of the worm to be almost entirely made up of uterus, with an insignificant alimentary canal pressed to one side.

The period of incubation is from 8 to 12 months.

Usually there are no other symptoms than discomfort from the blister and a feeling of heaviness about the affected extremity. At times there may be pain and fever. The parasite may fail to gain exit to the skin surface or die before reaching maturity. In such cases she may become calcified or give rise to abscess formation. The _x_-ray plate may show a convoluted cord-like structure with frequent breaks in the line.

[Illustration: FIG. 105.—Guinea worm (_D. medinensis_). Rolled on a stick for gradual extraction. (From Greene’s Medical Diagnosis.)]

_Treatment._—By douching the point of exit we may cause the uterus to empty itself in about three weeks. At that time we may commence extraction by intermittent traction by winding the worm around a large toothpick or similar object. If undue force is exerted the worm may break off and abscess formation or sloughing result.

Macfie has reported success in treating 23 cases of dracontiasis with tartar emetic. He gave 1 grain intravenously every other day and found that it was not necessary to give more than 6 grains in the course of treatment. The inflammation quickly yielded and the discharge from the sore ceased rapidly.

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