A bacterial or parasitic
disease causing abdominal pain, diarrhea,
and fever. In children, bacillary
dysentery due to Shigella species is a common endemic
or epidemic disease, and is associated
with poor hygiene. It is a short-lived illness but may cause dehydration
in severe cases. The organism may be carried in feces
in the absence of symptoms. Antibiotics
may be used to shorten the attack and reduce carrier rates.
|Amebic dysentery is caused by the microbe Entameba
histolytica, found in contaminated water and food. Entameba is
a natural inhabitant of the gut, however, under certain conditions
invasion of the gut wall occurs. Ingested Entameba cysts
undergo division and multiplication in the large intestine (1). After
division, eight trophozoites (feeding protozoa) are produced (2),
non-infective trophozoites remain in the intestine (3) feeding on
bacteria and food particles. Infective trophozoites invade the gut
wall (4), multiply and dissolve away tissues by producing protein-digesting
enzymes. If organisms enter the blood stream (5) they can be carried
to the lungs (6), liver and brain where abscesses develop. Those released
from gut abscesses reinvade tissues or form cysts (7) and are passed
in the feces. The disease is transmitted if flies carry cysts from
feces to food or, more commonly, drinking contaminated water (8).
dysentery, also called amebiasis, is a chronic
disease, usually seen in warm climates, with episodes of diarrhea and constipation,
accompanied by mucus and occasionally blood; constitutional symptoms occur
and the disease may resemble noninfective colitis.
Treatment with ementine, while effective, is accompanied by a high risk
of toxicity; metronidazole is a less toxic antiamebic agent.