THE 
TRICHINA SPIRALIS. 
BY 
\y 
EDWARD R. HUN, M.D. 
A PAPER READ BEFORE THE ALBANY INSTITUTE, 
JANUARY 5, 1869. 
ALBANY, N. Y. : 
J. MUNSELL, STATE STREET 
1869. TRICHINA SPIRALIS. 
The Trichina Spiralis is a round worm belonging to the 
class of Nematoidea, and is found as a parasite affecting 
man and certain animals. 
It was first found in human muscles by Mr. Hilton in 
1832, and three years later was described by Professor 
Owen, who gave to it the name of Trichina Spiralis, from 
its slender form and habit of coiling itself up in a spiral 
shape. From this time, until 1860, the Trichina was fre- 
quently observed in the muscles of subjects in the dissect- 
ing room, but no account was given, and no theory formed 
as to how it got there. In all these cases the worm was 
found enclosed in a calcareous cyst. 
Zenker of Dresden, in 1860, first called public attention 
to the fact that these little parasites, hitherto considered 
harmless, might be, and often were, the cause of severe and 
fatal diseases. A farmer, his wife and several other per- 
sons were attacked with a severe illness after eating of the 
flesh of a pig raised and slaughtered on their farm near 
Dresden —a servant who had eaten some of the meat died. 
Zenker, upon examination, found Trichinae in the ham, 
head cheese and sausages made from the pork, and the 
muscles of the dead girl were filled with them. He sent 
some of the muscle to Professor Virchow of Berlin, who, by 
a series of experiments upon animals, developed the follow- 
ing interesting facts: 
The Trichina, as found free in the muscles, is a round 
worm about one-twenty-fifth of an inch in length, rather 
more pointed at its cephalic then at its caudal extremity. 4 
A digestive canal runs the whole length of the animal, 
and at its posterior part is a closed sac running about one- 
third of its whole length and filled with granular matter. 
No sexual organs are to be seen. 
If portions of this muscle are introduced into the stomach 
of certain animals (as rabbits for example), and these ani- 
mals are killed and examined at different intervals, we find 
that the Trichina passes through the following stages of 
development. 
During the three days following its ingestion it grows 
rapidly in size, becoming from three to four times its ori- 
ginal length. At the same time sexual organs are deve- 
loped, and the closed sac, mentioned above as occupying the 
posterior portion of the body, becomes ovaries in the female 
and testicles in the male, and within from eight to ten 
days from the time of their entrance into the stomach each 
female Trichina gives birth to living young whose number 
has been estimated at from two hundred to one thousand 
from each parent. Whether the same individual becomes 
pregnant more than once, is not yet fully determined, but 
from some of the facts observed it is probable that they do. 
The young Trichime are exceedingly minute and thread- 
like, and commence immediately after birth to bore through 
the walls of the stomach and intestines containing them, 
and disseminate themselves with wonderful rapidity all 
through the muscular tissue. It is a curious fact that they 
are found to locate themselves only in the tissue of those 
muscles which are under the control of the will, never 
having been found in the heart or muscles of organic life. 
After reaching their destination in the muscle they in- 
crease gradually in size until they attain one-twenty-tifth 
of an inch in length, and then coil up in a spiral form and 
remain quiet in the midst of the deposit of fibrinous matter, 
which the irritation of their presence has caused to be depo- 
sited around them by the vessels supplying nutriment to the 5 
part. This afterwards contracts, enclosing each worm in a 
separate sac, which is finally in its turn enveloped by a 
deposit of calcareous matter. The Trichina now remains 
quiescent in his shell for an indefinite period of time, wait- 
ing until some unfortunate animal shall receive him into 
his stomach, when the acid contained in the gastric juice dis- 
solves the-walls of his prison house, and sets him free to 
give birth to a new generation, who go through a similar 
cycle of existence, while the parent worm dies and passes off 
with the intestinal evacuations. It follows from the above 
observations that the Trichinae have four distinct phases 
of existence : 
1st. The Trichinae, when swallowed, stop in the intes- 
tine, complete their development there, give birth to young, 
and then die. 
2d. The little Trichinae, as soon as born, migrate into 
all the striated muscles, except those of the heart. 
3d. Having reached the muscular system they increase 
in size but not in number. 
4th. They become encysted and remain quiescent until 
eaten by man, or certain animals, when they in turn give 
birth to a new generation, after which they die. 
The symptoms produced by this parasite vary according 
to the number swallowed and to their different locations 
in the body, and the disease called Trichinosis may 
be divided into three stages: 1st. The period of a intes- 
tinal irritation. 2d. The period of muscular irritation; and 
3d. That of convalescence or termination. 
The severity of the symptoms of course vary greatly in 
different cases. Sometimes the intestinal irritation is so 
slight as to pass unnoticed by the patient, while, on the 
contrary, it at other times results in diarrhoea with bloody 
discharges, with severe abdominal pain, and more rarely in 
constipation. The tongue is ordinarily dirty and coated. 
There is nausea, with mucous or bilious vomiting, tumefac- 6 
tion of the abdomen, and in severe cases painful colics. The 
pulse is always rapid, and the skin hot. The patient hardly 
ever dies during this stage of the disease. The second 
period of muscular irritation is always present, unless the 
number of Trichinee ingested is very small. When we con- 
sider that each female gives birth to four hundred or five 
hundred young at least, we can understand how a few 
mouthfuls of the infected meat may give rise to millions of 
little worms, each of which bores its way all over the body 
of the patient. This period usually lasts from four to five 
weeks, and commences with languor and chills, followed by 
pains in the limbs, and a puffy swelling of the eye-lids and 
face, which is scarcely ever absent. This swelling often 
attacks the upper and lower limbs as well as the face. The 
muscular pains are very acute, and the slightest motion or 
pressure produces extreme agony. The tongue becomes 
swollen and painful, and the pulse rises from 115 to 130 
per minute, while the diarrhoea often continues, and the 
abdomen is tumid and tender. Sleep is almost entirely 
destroyed, and the thirst becomes very urgent. There is 
often a troublesome cough, which increases the pain and 
soreness. During this period the patient, if he is able to 
walk at all, does so upon his toes, as if unable to put his 
heel to the ground. These symptoms usually abate after 
from the twentieth to the fortieth day, but the patient 
remains worn out and exhausted, and the third period, or 
that of convalescence, is usually long. 
Unfortunately all cases do not reach the stage of convales- 
cence. Death often takes place during the second period, 
or at the commencement of the third, and the patients die 
with symptoms resembling those of a severe case of typhoid 
fever. 
Thus far it has always been observed that Trichinosis 
in man has resulted from eating pork, but the hog is not 
the only animal in which this parasite has been found 7 
to exist. Among the animals in which Trichinae are 
found without the intervention of human agency, are: the 
hog, cat, rat and mouse, mole, badger, etc.; and of 
birds, the owl, crow, raven, hawk, etc. Besides these, it 
is found that the administration of diseased meat will pro- 
duce the Trichinae in the Guinea-pig and rabbit, and the 
chicken and pigeon. It has been found impossible to tri- 
chinose beef, horse, ass, mutton, etc., or the goose, duck or 
turkey. Experiments have also been tried on fishes, but 
with a negative result. It is by no means probable that 
Trichinosis is so rare a disease as it is commonly supposed 
to be. 
It is not an easy disease to detect, because it has 
no pathognomonic symptoms. During the first period 
the symptoms might easily be mistaken for those of dys- 
entery while during the second stage the oedema of the 
face and limbs greatly resemble the early stages of Bright’s 
disease of the kidneys, and the muscular pains are not 
unlike some severe cases of rheumatism. The third period 
has, according to Virchow, been mistaken for consumption. 
The epidemic of Trichinosis which occurred at Hettstadt 
was at first considered to be cholerine, while that at Mag- 
debourg was for some time called by a false name. 
In a medico-legal point of view, this disease presents 
points of great interest. The following case will give a 
just idea of its importance; 
In February, 1865, Langenbek operated upon a man at 
Berlin for a tumor of the neck. During the operation, he 
remarked that the muscles were filled with encysted trich- 
inae. Upon asking this man if he had ever had any 
previous illness, he stated that in 1845, he had with others 
inspected the schools at Jessen; that eight of them had 
breakfasted together upon ham, sausage and white wine, 
with the exception of one who only took a glass of red 
wine. All the other seven, including the man who had 8 
been operated upon, fell sick, and four of them died. 
Suspicion naturally fell upon the innkeeper, and an inves- 
tigation was made without result. Nevertheless the inn- 
keeper continued to be suspected of having poisoned his 
guests, and he was obliged to emigrate to America. The 
mortality of this disease is not so great as is usually 
estimated, as is shown by the following statistics taken 
from some of the epidemics. At Plauen, two deaths out 
of fifty cases. At Calbe, seven out of thirty-eight. At 
Hettstadt, twenty-seven out of one hundred and fifty-eight; 
and at Bourg, eleven out of fifty. 
Virchow arranges the measures to be taken in order to 
prevent the propagation of the Trichinae under three 
heads: 1st. Preventing as far as possible the infection of 
swine by Trichince. This can only he done by close attention 
to their food and cleanliness, for, since we cannot admit the 
spontaneous generation of Trichinae in the pork, their pre- 
sence necessarily presupposes that infected meat must 
have been taken into the stomach of each diseased hog. 
2d. The meat should be carefully inspected before being delivered 
to the consumer. This can only be done properly by means 
of the microscope; for, to the naked eye, the diseased meat 
offers no abnormal appearance, except in cases where the 
parasites have existed in the muscles for a long time, and are 
surrounded in a thick cyst of calcareous matter, when they 
may be seen upon careful examination as little white 
specks. 3d. Before being placed upon the table, pork should 
be thoroughly cooked. It is not an uncommon habit among 
certain classes to eat the pork raw, in which case thegreatest 
danger, of course, threatens the consumer. But even after 
cooking or smoking, the central part of a large piece of 
pork, often does not reach a sufficiently high degree of 
temperature to destroy the vitality of the Trichina;, and 
as now-a-days hams are often sold as smoked which have 
simply been rubbed over with creasote, pyroligneous acid or some other empyreumatic substance, we find that eating 
cooked pork is not entirely devoid of danger. It has, how- 
ever, been shown by Virchow that a temperature of 210°, 
or a warm fumigation of twenty-four hours duration, infal- 
libly destroys the Trichinae. 
I have given this short account of the Trichina this even- 
ing, thinking that it might be of interest to the members 
of the Institute, and especially because I have met with 
two cases of this disease in this city. I was invited by Dr. 
C. D. Mosher to see two of his patients, one of whom was 
evidently dangerously sick, and yet presented a train of 
symptoms which did not conform to any of the ordinary dis- 
eases which prevail in this locality. Two boys of German 
parentage came into the house hungry one morning, and 
finding a piece of pork unon the table ate some of it raw. 
The remainder was cooked and eaten b}7 the family at din- 
ner time. A few days afterward the elder boy, aged four- 
teen years, became sick and vomited several times. Was fe- 
verish, and his eye-lids and face were swollen. Then a 
general soreness attacked his whole body and limbs, which 
confined him to the bed for a few days, after which it 
gradually abated, so that when I saw him some six weeks 
afterward he was quite well, except slight soreness on pres- 
sure about the muscles of the arms. The younger boy, 
aged ten years, was not so fortunate. lie, too, became sick 
a few days after eating the pork. Ilis face and limbs be- 
came swollen, and he was attacked with a severe diarrhoea. 
The muscular soreness became intense, and he walked on 
his toes with the heels off the ground for three weeks, 
after which he was obliged to lie still in bed, the least 
motion causing extreme pain. About this time a trou- 
blesome cough commenced, and the effort of coughing 
increased the soreness. He could not sit up, hut remained 
stiff and extended upon his back. The least pressure 10 
upon the limbs caused him to cry out in agony. This 
was !us condition when I saw him last. 
By means of a small instrument, which I had constructed 
for the purpose, I removed a little piece of muscle from the 
shoulder of the eldest hoy, which T have examined under 
the microscope, and find studded with trichime which 
are coiled up and quiescent, preparatory to becoming en- 
cysted. Theyounger boy was so tender to the touch that 
I was unwilling to submit him to the pain of the opera- 
tion. 
Note.— Since the above paper was read before the Insti- 
tute, the younger boy has died, and a microscopic exa- 
mination of the muscles showed them to be everywhere 
filled with Trichinae, in some of them enveloped in a newly 
formed cyst, and others free and full of life and motion. 
In order to give some idea of their number I may state that 
I counted forty-one trichinae in a single field presented by 
a lens of one-inch focal distance.