Chapter L: The Faeces and the Alimentary Tract in Tropical Diseases

THE FAECES

It is advisable to examine a stool macroscopically before taking up
the microscopical examination. Pus or blood in stools may often be
noted without the aid of the microscope.

The normal stool is sausage-shaped and soft.

The mucus of bacillary dysentery is opaque and grayish from the
great number of pus and phagocytic cells. It is well to remember
that Charcot-Leyden crystals, which are practically always absent
from bacillary dysentery stools, are not infrequent findings in
the amoebae-containing stools; of course, these crystals appear in
other intestinal parasite infections.

In obstruction of the common bile duct we have acholic, whitish,
foul-smelling stools. If the putty color be due to bacterial change
exposure to the air will restore the brownish tinge.

Sprue stools are whitewash to putty-colored, pultaceous, and filled
with air bubbles. The amount is excessive.

A very practical way of obtaining amoebae is to pass a rectal tube
or a piece of drainage tube with fenestrations into the bowel, and
amoebae may be found in the mucus filling the perforations in the
tube.

Ordinarily the stool is best collected in quart fruit jars
and examined as soon after evacuation as possible. The wooden
spatula-like tongue depressors are well adapted for handling the
specimen.

In examining a stool, it is well to color the drop of faeces, which
is to be covered with the cover-glass, with a small loopful of ½%
solution of neutral red. If diluting fluid is used, it should be
salt solution, and not water. The neutral red tinges the granules
of the endoplasm of amoebae and flagellates a very striking
brown-red color, thus differentiating them from vegetable cells or
body cells.

Encysted protozoa are difficult to diagnose, unless one possesses
considerable experience. In examining for encysted amoebae as well
as for bringing out the number of flagella of flagellates I now use
the following method: Take a clean slide and make a vaseline line
across it about 1 inch from the end. A drop of the iodine solution
is placed on the slide about ½ inch from the vaselined line and a
suitable portion of the faeces to be examined is emulsified in it.
The edge of a square cover-glass is then applied to the vaselined
line and allowed to drop on the preparation. By pressure suitable
thicknesses of fluid can be examined. There is an absence of
current motion.

Epithelial cells are generally more or less disintegrated. In
the mucus of bacillary dysenteric stools, however, large intact
phagocytic cells are frequent, which may be mistaken for encysted
amoebae, and the polynuclear cell count averages 90% as contrasted
with the average polynuclear count of 7.5% in amoebic dysentery.

When a smear preparation is desired, we may smear out a fragment
of mucus and stain by Romanowsky’s or Gram’s method. Beautiful
preparations may be made by mixing the faeces with water, then
centrifuging for one minute. This throws down vegetable débris
and crystals. Now decant the supernatant fluid, which holds the
bacteria in suspension, and add an equal amount of alcohol. Again
centrifuge, decant, and smear out and examine the bacterial
sediment.

Simply taking a small mass of faeces and emulsifying it with a wooden toothpick on a concave slide in 70% alcohol—then, after the sediment settles, taking up a loopful with platinum loop from the surface and smearing out, gives a very satisfactory smear. Gram’s method, with dilute carbol fuchsin counterstaining, gives the best picture.

To culture for typhoid, dysentery, cholera, or other bacteria,
take up the material in a tube of sterile bouillon and smear it
out with a swab over a lactose litmus agar plate or an Endo or
Conradi-Drigalski plate. Before streaking the plates they should
be very dry on the surface. This can be best done by pouring the
melted agar into a plate with a circular piece of filter-paper in
the lid and placing in the incubator for one-half hour to dry. The
filter-paper absorbs the moisture. Then inoculate the surface of
the plate with the faecal material.

=Teague Medium.=—We have formerly preferred the Endo plate for typhoid work and the lactose litmus agar when culturing for dysentery bacilli. More recently we have obtained most satisfactory results with the Teague medium. The colon colonies, after eighteen hours, are deep black and opaque while the typhoid-dysentery group show colorless, transparent colonies.

The medium is prepared as follows: Nutrient agar is made in the
usual way, containing 1.5% agar, 1% Witte’s peptone, 0.5% sodium
chloride, and 0.5% Liebig’s meat extract, to the liter of distilled
water. It is cleared with egg-white, placed in flasks, and
sterilized in the Arnold sterilizer on three successive days. The
reaction is brought to plus 0.8. The agar is melted and saccharose
0.5% and lactose 0.5% are added. The medium is then heated for ten
minutes in the Arnold. To every 50 cc. of the medium are added 1
cc. of 2% yellowish eosin and 1 cc. of 0.5% methylene blue. The
mixture is shaken and plates poured. Eosin solution should be added
first.

=Occult Blood.=—In performing the test for occult blood, one should exclude the possibility of blood reaching the bowels from an extraneous source, such as ingested foods, mouth, nose, lungs and vagina, and the absence of interfering substances should be ensured. An absolute milk diet, or, at least, a diet containing neither meat nor green vegetables, is indicated for two or three days prior to the test, and all medication should be suspended. The technique noted on page 524 should be followed scrupulously when dealing with faeces.

It has been suggested that the absence of occult blood from the faeces may be accepted as an indication of cure in ancylostomiasis.

=Ova in Faeces.=—It is in the faeces we examine either for the parasites or for their ova in connection with practically all the flukes, except the lung fluke and the bladder fluke; for intestinal taeniases and for practically all the round-worms, except the filarial ones.

In the tropics, the examination of the faeces exceeds in value that
of urine and is possibly more important than blood examinations.

=Helminthiasis Statistics.=—There is one point in connection with the statistical reports as to the presence of intestinal parasites in a given section of the tropics that I desire to emphasize.

Because a limited district shows a certain prevalence of intestinal parasites we should not conclude that the entire country from which such findings emanate shows a similar extent and type of infection. Take for instance the Philippine Islands.

In 1910, there were made in Cavite Province 932 stool examinations
upon specimens from cases of sick people and of these only such
patients as it was thought required such an examination for
diagnostic reasons were made to bring such a specimen of faeces.

Of the 932 examinations, 135 or 14.4% failed to show the presence
of intestinal parasites or their ova. The remaining positive
examinations gave findings as follows:

-------------------+----------------------+---------------
Organism | Number of infections | Per cent.
-------------------+----------------------+---------------
_Ascaris_ | 627 | 67.2
_Trichocephalus_ | 607 | 65.1
Flagellates | 135 | 14.4
Amoebae | 111 | 10.9
Hookworm | 23 | 2.4
_Taenia saginata_ | 3 | 0.3
_Balantidium_ | 1 | 0.1
_Strongyloides_ | 1 | 0.1
-------------------+----------------------+---------------

At Bilibid Prison, Garrison encountered amoebic infection in 23% of
the cases. In the medical survey of Taytay, his findings were 2.7%.
Rissler and Gomez report only 0.39% of amoebic infection in their
examinations in Las Piñas and no cases showing such infections in
Tuguegarao and Santa Isabel. Such numbers are in striking contrast
with those of former investigators, some of whom have reported as
high a percentage of infection as 70.

Our findings as regards flagellates (14.4%) corresponded fairly
closely with those of Garrison, namely, 21% at Bilibid and 5.5% at
Taytay.

Garrison, for _Trichocephalus_ infection, obtained 59% at Bilibid
and 77% at Taytay; Rissler and Gomez give 53% at Las Piñas; 25.9%
at Tuguegarao, and 6.23 at Santa Isabel. Our findings were 65.1%.

As regards _Ascaris_ we found a higher rate of infection than for
any other parasite (67.2%). Garrison encountered 26% at Bilibid and
82.9% at Taytay. The percentages of Rissler and Gomez are 77, 73,
and 60 respectively for Las Piñas, Tuguegaroa, and Santa Isabel.

Garrison noted at Bilibid an incidence second only to
_Trichocephalus_ for hookworm infection, namely 52%. His percentage
of infection at Taytay was 11.6. Rissler and Gomez found 11.14% of
all cases examined infected with hookworms at Las Piñas, 8.01%
in Tuguegarao, and 45.38% in Santa Isabel. We noted only 2.4% for
Cavite, San Roque, and Caridad.

Our findings as regards _Strongyloides_ (0.1%) were far below
those reported by Garrison at Bilibid (3%) and at Taytay (0.7%).
Rissler and Gomez found 2.24% infected in Las Piñas, but no cases
were encountered in Tuguegarao and Santa Isabel. The same factors
influencing hookworm infection in this locality may be operative
for _Strongyloides_. Garrison found 0.2% of the individuals
examined at Taytay to be infected with ciliates, while Gomez and
Rissler failed to find such infections at Tuguegarao or Santa
Isabel. We found a single case in the 932 examinations.

THE ALIMENTARY TRACT

The Mouth

In _pellagra_ we have moist fissuring at the angles of the mouth with a large indented tongue with central coating and bare tip and sides. There is often a glairy mucus covering these red borders on the side. The fungiform papillae are prominent. Later on the tongue may become fissured and uniformly red. The buccal mucosa shows a carmine flush. The gums are tender but there is not the tendency to aphthous ulcers one sees in sprue. The flow of saliva is frequently increased.

In _sprue_ there is at first great sensitiveness of the buccal mucosa so that articles of moderate pungency give rise to painful burning sensations. The tongue becomes quite sore with vesicle formation along borders and tip which soon turn into ulcers. Ulcerations also occur on the buccal mucosa, particularly at the site of the posterior upper and lower molar teeth (Crombie’s ulcer).

The congestion causes a great increase in mucus especially about
the faucial pillars and pharynx. Ulcers are common about the
fraenum of the tongue. While the tongue is coated at first with
red ulcerated tip and sides it later becomes bare of any coating,
red and finally even glazed as though varnished. It is at times
fissured.

_Onyalai._—A very peculiar disease of Portuguese West Africa and possibly the Soudan region, known as _onyalai_ is characterized by the appearance of blood-distended vesicles of the mucosa of the cheeks and hard palate. The tongue is often swollen. The skin may show haemorrhages and haematuria is not infrequent. The mouth blebs vary in size from that of a split pea to a diameter of ½ inch or more. The cause is unknown.

_Herpes labialis_ is not so common in tropical as in temperate climate malarias. It is absent in plague pneumonia.

In _leprosy_ the nodules which form on the inside of the cheeks and
fauces tend to show ulceration and thickenings. The discharges from
the ulcerations in the nose, especially that on the vomer, reach
the pharynx and such leprosy bacilli-containing discharges may be
expectorated and cause one to consider the material as coming from
the lungs.

In _yellow fever_ the bleeding from the gums usually precedes the black vomit.

In _kala-azar_ and possibly in _malaria_ we may have gangrenous
conditions of the cheek, as cancrum oris.

In the miliary type of _verruga_ we may have the granulomatous lesions appearing on the mucous membranes of the mouth.

In _typhus_ fever the mouth is strikingly foul with marked sordes
covering the teeth. The dry brown tongue in this disease is known
as the “parrot tongue.”

We may rarely have parotid gland enlargement in _Malta fever_, _malaria_ and _tsutsugamushi_.

Parotitis is not uncommon in typhus fever. A type of parotitis
which differs from mumps in not being contagious has been reported
from the Philippines.

Stomach and Oesophagus

Very important in diagnosis is a tenderness in the pyloric end of the stomach, which is brought out by attempting to palpate the epigastric region. It is marked in yellow fever and acute pernicious beriberi as well as in blackwater fever and bilious remittent fever. We also frequently have epigastric tenderness, extending to the right, in ancylostomiasis.

Hookworms patients are often “pot-bellied” and the craving for
eating unusual articles, as earth, may be connected with the
gastric hyperacidity which the patient desired to neutralize with
alkaline earth.

_Sprue_ gives a flatulent dyspepsia with gaseous eructations.

_Pellagra_ gives eructations and pyrosis and very common is a burning sensation going up from the stomach along the line of the oesophagus.

The esophagus is raw in _sprue_ so that swallowing is painful.

Nausea and Vomiting

So many diseases are attended with nausea, besides those in which nausea is accompanied by rather constant vomiting, that it would hardly seem advisable to consider it alone. At the same time the slight nausea which often accompanies _bacillary dysentery_, as one of the manifestations of toxaemia, is of value in differentiating this type of dysentery from the amoebic one.

In _yellow fever_ there may be early vomiting of whitish or
bile-stained mucus but the well-known black vomit is a later
feature, only occurring after the fourth day when the other
haemorrhagic manifestations set in.

Bilious vomiting is the feature in _bilious remittent fever_ which
causes the patient the greatest distress.

In _blackwater fever_ the frequent retching and bilious vomiting tend to exhaust the patient and the persistent vomiting of green bile often precedes death.

Bilious vomiting may be quite a feature of the icteric type of
_relapsing fever_.

_Vomiting sickness._—There is a disease known as _vomiting sickness_ which has been noted in Jamaica. It occurs chiefly in children and has a sudden onset with marked vomiting followed by cerebral symptoms and great mortality. Some have thought the disease to be yellow fever but the fever and jaundice of that disease are absent. Scott has thought it to be epidemic cerebro-spinal meningitis, but more recently has suggested that it is possibly due to the eating of some poisonous substance, plant or otherwise, and that it is not an infectious disease. It is now recognized as due to ackee poisoning.

Vomiting is often a sign of dangerous vagal involvement in _acute
pernicious beriberi_. Some consider that the extreme dilatation of
the right heart, pressing on the stomach, may be the excitant of
this vomiting.

The vomiting of _cholera_ follows the diarrhoea. The material vomited may be of the same character as the rice-water stools.

In _ptomaine poisoning_ vomiting precedes the diarrhoea.

Rarely a _liver abscess_ may burst into the stomach, in which case
we would have the vomiting of pus. Of course the more common route
is by the lungs in which case the chocolate-colored liver abscess
pus would be coughed up instead of vomited up.

The Intestinal Tract

It is usual to consider constipation as a clinical feature of such diseases as plague, yellow fever, Malta fever, beriberi and tsutsugamushi, as well as typhus fever.

Abdominal pains are most often connected with _dysenteric_
conditions and it is customary to state that the greater the
tormina, or intestinal griping, the nearer is the dysenteric
process to the caecum.

In _cholera_ the cramping of the abdominal muscles may follow that of the calf muscles.

In _sprue_ we may have a doughy sensation on palpating the abdomen
due to the fermenting contents of the intestine.

In the algid type of _pernicious malaria_ the abdominal griping may be severe.

Tenesmus is the condition which along with tormina gives a diagnosis of some form of dysentery.

In rectal _schistosomiasis_ the thickenings and blood
extravasations, resulting from the eggs extruded by the fluke,
may give rise to prolapse of the rectum. This may also occur in
severe bacillary dysentery and in a disease of British Guiana
and Venezuela, known as _epidemic gangrenous rectitis_, prolapse
and gangrene of the rectum may occur. The symptoms are those of
gangrenous dysentery.

Diarrhoea

The chronic diarrhoeas of the tropics are often associated with amoebic dysentery and in such cases we generally get a history of recurring attacks of diarrhoea separated by periods of constipation.

In _sprue_ the condition generally sets in as a morning diarrhoea, very profuse and painless. _Hill diarrhoea_ also shows frequent stools of whitish color from early morning until about noon.

The typical stool of _sprue_ is a gas-permeated, putty-colored,
offensive mass, extraordinarily copious.

In _cholera_ the rice-water stool, which is not attended by pain,
causes an unusual sense of prostration even at the onset of the
stage of evacuation.

In _pellagra_ we often have a recurring diarrhoea or mild
manifestations of dysentery.

The stool of pellagra is darker and less copious than that of sprue
and shows only a normal fat content while that of sprue is very
fatty—as much as 30% of ingested fat appearing in the sprue stool
as against the 5% for the normal one.

In _Japanese schistosomiasis_, following the stage of urticarial fever, we have our best diagnostic means in examining the blood-tinged bit of mucus capping the stool for the spineless ova of the fluke.

The _fluke diseases_ of the liver and intestines give rise to
various disturbances. The diagnosis is by the finding of the
specific ova.

In infections with _Strongyloides stercoralis_ there may be vague
manifestations of neurasthenia and diarrhoeal disturbances. Cochin
China diarrhoea was once thought to be a _Strongyloides_ infection.

Infections with amoebae, intestinal flagellates and ciliates are
discussed under dysentery.

Intestinal flagellates are so common in the stools of well people
in the tropics that one should be very careful in assigning a
pathogenic rôle to them.

It is now generally accepted that _Lamblia (Giardia)_ can bring
about exhausting diarrhoeas.

Intestinal Myiases

In the tropics vague intestinal disturbances or violent abdominal cramping may be brought about by dipterous larvae in the intestinal canal. The symptoms may be those of a dysentery and may be attended with fever and malaise. The biliary tract also may be invaded. For a more detailed statement of the several myiases, see Chapter XXV.

FIG. 159.—Larva of _Anthomyia canicularis_, enlarged. Rarely found in the stool. (Gould.) (From Tyson.)]

The larvae usually obtain access to the alimentary tract in food
taken in by the mouth. Flies of the genus _Sarcophaga_ are prone
to deposit their larvae on food, especially meat that is somewhat
tainted. Other flies, as _Musca_ or _Anthomyia_, may lay their eggs
on food. Flies of the genus _Anthomyia_ tend to lay their eggs on
plants.

It is possible for a fly to deposit its eggs or larvae about the anus while the man is at stool.

Great care must always be observed to assure one’s self that fly
larvae, which may be present in the stool, have not originated from
larvae deposited on the stool subsequent to its passage.

DETERMINATION OF DIPTEROUS LARVAE

There are certain points in the anatomy of dipterous larvae which must be considered in recognition of the genus or family of the flies concerned in the various myiases. The broad extremity is the posterior one and the tapering one the anterior. The dark hook-like processes, which may be in pairs or fused, project from the anterior or head end and above them is a pair of projecting papillae. The second segment from the head has on either side projecting hand or fan-like structures with varying numbers of terminal divisions, 4 to 40 or more. These are the anterior spiracles.

The large terminal segment has on its posterior surface two
chitinized plates with 3 slits of various architecture in each.
These are the posterior stigmal plates and are the structures we
pay particular attention to in identification. In the early larval
stages there is only one slit; in the second stage there are two.
It is only in the fully developed larval stage that we note the
characteristic 3 slit stigmal plates. The presence or absence of a
rounded protuberance or button at the base of each stigmal plate
should be looked for. The area carrying the stigmal plates may be
sunken to form a pit. (See Fig. 135.)

KEY TO LARVAE OF THE MYIASES. (BANKS.)

1. Body with lateral and dorsal spinose processes Homalomyia.
Body without such processes 2
2. Body ending in two fleshy processes; rather small
species 3
Body truncate or broadly rounded at end 4
3. Processes bearing the stigmal plates; body about
5 mm. long Drosophila.
Processes not bearing the stigmal plates; body 10
mm. or longer Piophila.
4. But one great hook; posterior stigmal plates with
winding slits; no distinct lateral fusiform areas;
tip of body with few if any conical processes Muscinae.
With two great hooks; slits in the stigmal plate
not sinuous 5
5. No tubercles about anal area; no distinct processes
around stigmal field 6
Distinct tubercles above anal area; often processes
around stigmal field; lateral fusiform areas
usually distinct 7
6. Stigmal plates on black tubercles; lateral fusiform
areas distinct Ortalidae.
Stigmal plates barely if at all elevated; lateral
fusiform areas indistinct; stigmal plates often
contiguous or nearly so; slits long and
subparallel Trypetidae.
7. Slits in stigmal plates rather short, and arranged
radiately 8
Slits slender and subparallel to each other 9
8. Two tubercles above anal area; stigmal field with
distinct processes around it Anthomviidae.
Four or more tubercles above anal area; slits of
stigmal plates usually pointed at one end Muscinae.
9. A button to each stigmal plate; slits rather
transverse to body Calliphorinae.
No button to stigmal plates, slits of one plate
subparallel to those in opposite plate; plates
at bottom of a pit Sarcophagidae.

A specimen of stool containing fly larvae may be incubated in a moist chamber in order to obtain the imago for species determination.