The Animal Parasites of Man

by Harold Benjamin Fantham; Max Braun; J. W. W. Stephens; Fred. V. Theobald

Eustrongylus gigas.

Eustrongylus gigas is most frequently found in the pelvis of the kidney. Infection in the majority of cases leads to pyelitis. The inflammation extends to the capsule from the pelvis, resulting in a purulent nephritis. In infections of longer duration, the affected kidneys become changed into so-called kidney sacs, while the kidney itself continuously shrinks. Owing to the worm fixing its posterior end in the ureter, and owing to an inflammatory swelling of the mucosa of the ureter, the passage of urine becomes very difficult.

The symptoms resemble those caused by a foreign body, e.g., kidney pain, suppression of urine, dysuria, discharge of blood and pus with the urine. But these symptoms are not sufficient for a diagnosis; this can only be established by finding eggs or the parasite itself in the urine.

Moscato[833] records a case with chyluria, pain in the region of the right kidney, and hysterical symptoms. During an hysterical attack a specimen of Eustrongylus gigas was discharged in the urine, and the chyluria and nervous affections disappeared. In a case described by Stuertz[834] of an Australian with chyluria due to Eustrongylus gigas the chyluria had existed for seven years. In the urine the eggs of Eustrongylus gigas were found. The cystoscopic examination showed that turbid urine was discharging from the left ureter. Nephrectomy was considered.

Ancylostoma duodenale (Ancylostomiasis).

Whilst up to quite modern times it has been generally maintained that the great majority of worm diseases cause more or less marked symptoms, the exact investigations of the last few years have made it plain that the great majority of people with worms are not only perfectly healthy, but the most careful clinical observations show no single sign of any ill-effect of the intestinal parasites on the health of the host (Löbker and Bruns[835]). If infection has led to the development of only a few ancylostomes, then injury to the general health is, as a rule, scarcely noticeable. In order to produce severe illness the presence of several hundred worms in the intestine is necessary, and in general the intensity of illness varies in exact proportion to the number of worms. Then the duration of the infection comes into play: the longer the human organism is submitted to the injurious effect of the parasite, the clearer is the effect on the host. Besides, the resistance of the individual has to be considered. Whilst a more robust person can harbour without ill-effect for a longer time a larger number of ancylostomes, the symptoms of the disease become more markedly and much sooner apparent in weakly persons or in those weakened by other diseases.

The first symptom is disturbance of the digestive system; more often there is a feeling of pain in the epigastrium, more severe upon pressure, heartburn, nausea, vomiting of mucus or food at different times of the day (occasionally ancylostome ova have been found in the vomit). Whether the eggs which reach the frontal sinus with the vomit can develop into larvæ there is questionable, but the records of v. Ziemssen[836] and Huppertz,[837] to the effect that in some instances ancylostomes have been discharged from the frontal sinus, are of interest. The five cases recorded by the latter had a fatal termination from œdematous swellings of the face with severe inflammation of the meninges. The tongue is furred, and extensive catarrhal stomatitis and ptyalism are recorded. The appetite is variable, increasing or diminishing, there is loathing of nourishment or a marked longing for acid food and unripe fruit, whilst ordinary meals are rejected. At first there is often constipation, later diarrhœa with abundant mucus, and often blood in the stools; microscopically eggs and Charcot-Leyden crystals were found.

In the further course of the disease symptoms due to increasing anæmia predominate; the hæmoglobin of the blood diminishes from one-fourth to one-fifth of the normal (Baravalle[838]), the eosinophile cells increase considerably (Boycott,[839] Lohr[840]), yet in regard to diagnosis eosinophilia cannot be regarded as of equal value to a microscopical examination of the fæces (Bruns, Liefmann, and Meckel[841]). The disturbances of the circulatory system take the form of more or less severe palpitation, pain in the region of the heart, quick pulse, œdema of the eyelids, of the face, of the lower limbs, and even of the whole body. Disturbance of the sexual functions (impotence, irregular menstruation, delayed onset of puberty) are not infrequently observed.

Infection in human beings takes place by the mouth, if uncleansed vegetables are eaten—in Japan especially, where human fæces are used—and articles of food are not sufficiently carefully cleaned (Inouye[842]), or from putting food into the mouth with dirty hands. Looss[843] does not think that drinking water is dangerous as a rule, for the larvæ sink to the bottom in standing water, and are only brought to the top by shaking. Looss has done most valuable service by discovering that infection can arise also through the skin. During the last few years so many authors have confirmed this at first doubted source of infection, that one must accept this source of infection now, even though it is undecided which mode of infection is the more prevalent, by the mouth or through the skin. Some authors have described the changes induced in the skin by the penetration of the larvæ; for instance, Looss and Schaudinn,[844] itching papules in their own skin, and Dieminger[845] a skin affection in the Graf Schwerin mine which was called the “Schweriner itch,” and a skin affection not unlike scabies in the tea plantations of Assam and South America; pani-ghao (water itch) (Dubreuilh[846]); the penetration of the larvæ through the skin also explains the frequent appearance of boils and itching purulent eczema in miners in infected pits (Goldmann[847]).