CHAPTER IX
DYSENTERY
DEFINITION AND SYNONYMS
=Definition.=—The designation dysentery refers to a symptom-complex of (1) small, frequently passed mucous or muco-sanguinolent stools and (2) pains connected with spasm of the sphincter ani (tenesmus) or intestinal gripings (tormina).
The condition may be set up by numerous causes but of these two so outweigh the others that it is usual to have in mind either bacillary or amoebic dysentery when the term is employed.
=Synonyms.=—The Bloody Flux. French: Dysenterie. German: Ruhr.
GENERAL CONSIDERATIONS
As will be noted in the sections dealing with amoebic and bacillary dysentery our present knowledge of these conditions is of recent date. There was so much that was etiologically, epidemiologically and clinically contradictory that the subject was impossible of elucidation until the existence of a group of dysentery bacilli was generally accepted, following the reporting, in 1898, by Shiga, of his bacillus of dysentery.
Although Hippocrates was the first accurately to describe the disease we now know as dysentery yet there is good ground for believing that the disease existed in Egypt and India for centuries before Christ.
Many of the older writers failed to differentiate conditions which showed admixtures of mucus and blood in the stools from those with blood alone.
Commencing with the last century, authorities have considered the association of mucus with the blood as essential in clinical diagnosis.
It is interesting that with a better knowledge of etiology we are now recognizing as of dysenteric nature diarrhoeal conditions in which there is an absence of the typical stool of dysentery.
Our views as to the etiology and epidemiology of bacillary dysentery have been fairly definite for at least twenty years, while those relating to amoebic dysentery, notwithstanding the important researches of Kartulis, Councilman and Lafleur, Schaudinn and others have remained rather chaotic until quite recently.
_The Term Dysentery._—By the term dysentery we understand a symptom-complex of more or less characteristic stools and more or less characteristic pains.
As a rule the stool is composed of one or more teaspoonfuls of greenish yellow or dirty brown mucus, the altered blood being intimately admixed with the mucus, or we may have a whitish to grayish muco-purulent mass with streaks or flecks of blood on the outside. These mucoid masses may be found suspended in serous, sanguineous or more or less feculent discharges which are usually small in amount and passed with much frequency.
The terms tormina and tenesmus are the ones used to designate the characteristics of the pains of dysentery, tormina for the griping colicky pains, which center about the umbilicus or run in the direction of the large intestine, and tenesmus for the painful spasmodic contractions of the sphincter ani to which is due the sensation of lack of ability to complete the act of defecation leading to straining and justifying Manson’s description “glued to the commode.”
It is usually stated that the nearer the dysenteric process is to the rectum, the greater the tenesmus and the nearer to the caecum, the greater the tormina.
THE MODERN CLASSIFICATION OF DYSENTERIES IS BASED ON ETIOLOGY RATHER THAN UPON CLINICAL MANIFESTATIONS
Owing to the great importance of the two main kinds of dysentery, amoebic, or that caused by _Entamoeba histolytica_, and bacillary, or that caused by some strain of _Bacillus dysenteriae_, we shall consider them separately from the other causes of the dysenteric symptom-complex.
=A. Dysenteries caused by animal parasites.=
_Protozoal dysenteries._
1. Amoebic dysentery (_Entamoeba histolytica_).
2. Flagellate dysenteries (_Lamblia intestinalis_, _Trichomonas intestinalis_ and _Chilomastix mesnili_).
While in adults these intestinal flagellates usually cause only a diarrhoea, with at times marked nervousness, they may produce dysenteric symptoms in young children. The onset in children under three years of age may be insidious and attended with fever. The stool contains much mucus with only a little blood.
In cases of amoebic dysentery, the diarrhoeal attacks, which at times occur, are often associated with an abundance of flagellates, which may well be the cause of the complication. Cases of dysenteric diarrhoea have been reported from Gallipoli in which _Lamblia (Giardia)_ were apparently the only parasites involved. Such stools are often of a yellow ochre color. Relapses are common features of _Lamblia_ infections. _Lamblia_ is an inhabitant of the upper intestine while _Trichomonas_ and _Chilomastix_ belong to the large intestine, especially in the region of the caecum. While these last named flagellates are often found in the stools of those convalescent from dysentery there is a general opinion that they are nonpathogenic. These organisms may be present in diarrhoeal conditions in which case it is common to designate such diarrhoeas as flagellate diarrhoeas. Fantham and Porter have reported 187 cases of pure lambliasis.
In diagnosis it is important to recognize the encysted _Lamblia_. These are oval cysts, about 10 × 7µ and show a curved central line, with two lateral dots. When stained these dots show as chromatin areas. These cysts may be found in the faeces in great numbers. The vegetative _Lamblia_ has 4 pairs of flagella, is about 15µ long and has a tumbling motion. Calomel alone or calomel and ipecac give good results at times. Enemata of organic silver salts may be of benefit.
Porter recommends bismuth salicylate. Low has noted the tendency of lambliasis to recur and thinks many of the reported cases of cures are only temporary. His experience with bismuth, salol, thymol and cyllin has not been encouraging.
It is well known that lambliasis is of rather frequent occurrence in mice and rats so that these rodents may be factors in spreading the infection through the agency of their faeces deposited about human food.
Of other drugs recommended in treatment Dobell and Low have had no success with methylene blue, turpentine or beta-naphthol. These authors failed to find any increase in either large mononuclears or eosinophiles in a case of the infection.
Since Lamblia inhabit the upper parts of the small intestine, it may be that the administration of drugs by the duodenal tube will prove an effective method of treatment. Owens reports successful results in the treatment of amoebic dysentery from ipecac so administered. Stiles has recommended sulphur in lambliasis.
3. Ciliate dysenteries (_Balantidium coli_).
While various ciliates may cause a severe type of dysentery it is very exceptional that others than _Balantidium coli_ do so. This oval ciliate is from 60 to 100 microns long by about 50 to 70 microns broad. It is a commensal of hogs and the disease in man is usually found in those having the care of hogs. Infections have been reported from various parts of the world, temperate as well as tropical regions. These ciliates may be found in the faeces of persons apparently well but in such cases symptoms may eventually appear. The parasites multiply in the submucosa and the pathologic process is similar to that observed in the large intestine in amoebic dysentery.
The parasite is so large and has such an active motility that it would be impossible to fail to detect it in a microscopic examination of the faeces. Encysted parasites are round. The onset is rather insidious with diarrhoea which may be followed by dysentery. A severe form of anemia may be noted.
Ipecac, emetine, arsenic and quinine appear to be of little value in the treatment, but Walker considers the organic silver compounds, as protargol, etc., of value. Methylene blue enemata (1-3000) and 2-grain pills by mouth have been recommended.
[Illustration: FIG. 58.—Important pathogenic Protozoa of the intestinal tract. (1a) Motile _E. coli_. Note large amount of peripheral arrangement of chromatin in nucleus. (1b) Encysted _E. coli_. Note larger size than _E. histolytica_ cyst, 8 ring form nuclei and absence of chromidial bodies. (2) Motile _E. histolytica_ from acute dysenteric stool. Note histolytica nucleus with scanty chromatin. (3) Tetragena type of _E. histolytica_ from case of chronic dysentery. Note greater amount of chromatin and central karyosome with centriole. (4a) Preëncysted _E. histolytica_ from carrier. Note small size and heavy peripheral ring of chromatin in nucleus making this feature of chromatin in nucleus similar to the larger _E. coli_. (4b) Encysted _E. histolytica_ from dysentery convalescent. Note small size, 4 ring nuclei and a dark chromatin staining mass, “chromidial body.” (5a and 5b) Motile and encysted cultural amoebae from Manila water supply. (6a and 6b) Oocyst and sporozoite production in 4 spores of _Eimeria stiedae_. (7a and 7b) Oocyst with 2 sporoblasts and oocyst with 2 spores containing 4 sporozoites of _Isospora bigemina_. (8a and 8b) Vegetative and encysted _Trichomonas intestinalis_. (9a and 9b) Vegetative and encysted _Lamblia intestinalis_. (10) _Balantidium coli._ Illustrations of amoebae from Walker—others from Doflein.]
4. There are also dysenteric manifestations noted in the terminal stages of kala-azar (_Leishmania donovani_) and in algid pernicious malaria (_Plasmodium falciparum_). These conditions are taken up under the diseases kala-azar and malaria.
Wenyon noted a case of coccidial infection (_Isospora hominis_) in which there was a dysenteric syndrome. There have been about seventy cases of infection with this parasite reported, chiefly from soldiers serving in Gallipoli. The usual opinion is that they are nonpathogenic parasites. The oocysts are ovoid, with one end narrowed, and measure 28 × 14 microns. There are two sporocysts, each of which contains four sporozoites. The cyst when first passed is unsegmented.
_Helminthic dysenteries._—1. In addition to the protozoal causes above noted we may have dysenteric symptoms following infections with trematodes, especially _Schistosoma mansoni_ and _S. japonicum_. In these cases we have mucus coating the stool with more or less clotted blood in which mucus we may find the diagnostic ova. A rather high eosinophilia is present.
2. Infections with _Gastrodiscus hominis_ also give rise to dysenteric manifestations.
3. A very small cestode, _Heterophyes heterophyes_, has been noted to cause a condition suggestive of dysentery.
4. In 1902, Brumpt noted the finding of a nematode, _Oesophagostomum brumpti_, in the large intestine of an African native, which caused dysenteric symptoms and, more recently, another species, _O. stephanostomum_, has been reported as causing a fatal dysentery in a Brazilian at Manaos.
5. There have also been reported cases with dysenteric manifestations which were apparently connected with intestinal myiasis.
=B. Dysenteries caused by bacteria.=
1. Those caused by either the more toxic, nonacid mannite strain of Shiga, or the less toxic, acid mannite strains of the Flexner group.
2. Morgan has reported as the cause of certain bacillary dysenteries a bacillus known as B. Morgan No. 1. It is motile, produces indol, and in glucose bouillon gives a very slight amount of gas. It does not change mannite and does not produce a primary acidity in litmus milk. This organism is a frequent cause of summer diarrhoea of children. Flies from houses with such cases often show Morgan’s bacillus.
Paratyphoid infections may give the clinical picture of a colitis and such cases at times show a large amount of blood in the dysenteric stools. Usually the symptoms are rather those of an entero-colitis or a gastro-enteritis.
3. In Japan, dysentery-like epidemics of a very fatal disease, termed _ekiri_, occur among young children. The organism is very motile, producing gas and acid in glucose, but not in lactose media. It is reported at times to show indol production. Apparently a member of the Gärtner group.
4. Spirillar dysentery. LeDantec has reported a type of dysentery which shows the presence of great numbers of spiral forms. These are Gram negative and noncultivable. It is in question whether they belong to the bacteria. There is no fever in this type of dysentery.
5. Other bacterial causes. Cases of dysentery have been reported as caused by _B. pyocyaneus_, streptococci, atypical _B. coli_ and organisms of the Gärtner group.
In a _Pyocyaneus_ infection the color of the stools would be suggestive. This cause should be borne in mind in the dysenteric infections of debilitated children in the tropics. Some of the cases of so-called ptomaine poisoning due to members of the Gärtner group have clinical similarities to dysentery especially at the commencement of the attack.
=C. Dysenteries resulting from mechanical irritants or poisonous substances.=
A very interesting form of poisoning which gives rise to serious illness or death and is attended with marked abdominal pain and manifestations of dysentery is that reported from North China through the use of short lengths of bristles which are given mixed with the food.
Various irritant metallic poisons as arsenic, antimony and mercury may give rise to dysenteric symptoms. In cancer and syphilis of the rectum there may be a suspicion that the process is an ordinary dysenteric one.
Intussusception shows marked tenesmus with bloody rather than muco-sanguineous stools.
While dysenteric symptoms may be present in the terminal stages of various chronic diseases, especially tuberculosis and cardiac affections, yet it is in chronic nephritis, leading to uremia, that we may see symptoms of a marked catarrhal or even diphtheritic colitis.
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