Introduction
Mission
Statement
This web page, developed for an
undergraduate parasitology course at Stanford, is dedicated
to the parasite family Oesophagostomum, with an emphasis on
species that infect humans. The lifecycle,
classification, clinical
manifestations, epidemiology, diagnosis, treatment, and prevention are
all reviewed. In addition, there are a number of references, including
other web links as well as historical and current journal articles to which
the reader is referred for further interest.
Background
Oesophagostomiasis is a parasitic disease caused by species
in the family Oesophagostomum. Although it is a well known
parasite of goats, sheep, pigs, cattle, and monkeys,
Oesophagostomum can infect humans. Endemic to regions in Ghana and
Togo, this parasite has been termed the "nodule worm" because of the
nodules that form on the intestines of the host it infects. Its life
cycle is similar to that of the hookworm and thus it is believed that
humans become infected after accidentally swallowing the stage 3 larvae in
contaminated soil. The public health implications of this parasitic
disease in endemic regions is important yet very under-researched.
However, recent developments have provided improved treatment for
Oesophagostomum infection, better biomarkers for epidemiological
detection of the parasite, and better methods of diagnosis
for this disease.
History
The first case of Oesophagostomum infection was reported by Brumpti in
1905. The patient was a male from the Omo river near Lake Rudolph in East
Africa. The second case was described in more detail by Thomas et al.
five years later in an article entitled "The Pathological Report of a
Case of Oesophagostomiasis in Man," published in the Annals of
Tropical Medicine. A detailed description of the clinical pathology
was recorded (see "Case Study" below) which set the baseline to which
future cases of the disease would be compared to. Throughout the 20th
century, sporadic cases were reported in Brazil, Indonesia, and Uganda.
However, the majority of infections seems to be endemic to areas in Ghana
and Togo in West Africa. Because of better nutrition, sanitation, and
health care, the disease is no longer as fatal as it once was.
Oesophagostomiasis is still a serious health threat though and deserves
serious attention.
A Historical Case Study
The following is a case study of the first presentation of
Oesophagostomiasis by Brumpti.
The
patient: A
36 year-old male from the Amazon state, Rio Purus. He was emaciated yet had
well-developed muscles.
Chief Complaints: Patient presented with acute dysentery and
later became delirious.
Outcome: Died within 3
days. The following post-mortem was
observed.
Gross: Pale and scanty
subcutaneous fat; pale, brown muscle fibers;
white fluid in pericardium; left side of heart enlarged; disteneded small
intestine; surface of ileum, caecum, and colon were covered with nodules;
liver and spleen were slightly enlarged; small intestine was studded with
nodules for approximately 35 cm; 37 well-marked tumors identified, nodules were
either soft and gray
or small, hard, and opaque; nodules contained one worm at most; bowels were constricted; wall
of S.I. was thin; dark-blue tumor in appendix; some worms found penetrating
mesentery tissue;
submucosa, intramuscular, and subperitoneal regions all had cysts; cysts lining the colon
were yellow; small blood vessels were ruptured
where worm had penetrate nodule.
Post-Mortem Pathology Plates
All plates borrowed from Brumpti and Thomas. "The
Pathological Report of Oesophagostomiasis in Man." Annals of Tropical
Medicine. 1910.

Colon and small intestine tissue samples
from patient infected with Oesophagostomum. Important to note are the
nodules lining the lumen of the colon (right).

Worm protruding from nodule on the lining
of the colon.

Outside covering of encysted worm.
Introduction
Classification
Life
Cycle
Epidemiology
Clinical Manifestations
Diagnosis
Treatment
Links
References
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