(3) Treatment. The antibiotic of choice is ampicillin (100 mg/kg/d) which can
be given for 5 to 7 days orally in 4 divided doses. If there is improvement, do not
continue with the medication any longer even if the stool cultures are still positive.
Other medication effectively used in treating dysentery are tetracycline,
chloramphenicol, or co-trimoxazole. Actually the use of even mildly toxic antibiotics is
usually not justified because the majority of cases are mild and self-limited. For all
moderately or severely ill patients, parenteral hydration and correction of acidosis and
electrolyte disturbances are a necessity. Give clear fluids for 2 or 3 days after the bowel
has been at rest for a short time and offer the patient small frequent feedings with a diet
that is soft and easily digestible. Whole milk, high residue, and fatty foods should be
avoided. If cramps are severe, anti-spasmodics (i.e., tincture of belladonna) may be
helpful. Place the patient on effective stool isolation precautions to limit the spread of
infection.
b. Cholera.
(1) General. Cholera is an acute bacterial diarrheal disease of the small
intestine. Cholera is caused by Vibrio cholerae which are transmitted by food or drink
that is contaminated by feces containing a large number of vibrios. These vibrios
produce a powerful exotoxin in the small intestine (in particular, the ileum) where they
grow. The reduction of the sodium reabsorption causes massive diarrhea that is fatal in
50 percent of cases if untreated. This exotoxin induces hypersecretion of water and
chloride in the small bowel.
(2) Signs and symptoms. Cholera victims experience a sudden onset of
painless, watery diarrhea of up to 15 liters per 24 hours. The liquid stool is grayish
containing mucus and food particles. There is no fecal odor, blood, or pus, but rapid
dehydration takes place. The patient may have occurrences of vomiting and becomes
markedly dehydrated and acidotic. His eyes are sunken and he experiences intense
thirst, hypotension, a subnormal temperature, oliguria, shock, muscle cramps, and
coma.
(3) Treatment. The loss of water and electrolyte must be restored
immediately and continuously, and acidosis must be corrected. Replacement of oral
fluids (same volume as that lost) may be possible in the moderately ill patients. If the
patient is unable to take fluids by mouth, an I.V. infusion of Ringer's lactate must be
used to replace the fluids until the blood pressure and circulating blood volume are
restored. The medication used to suppress vibrio growth and shorten the time of vibrio
excretion is tetracycline, 0.5g given orally every 6 hours for 3-5 days. If untreated,
cholera lasts 3-5 days and has a mortality rate of up to 80 percent. If the victim receives
prompt and competent treatment, however, the mortality rate can be reduced to 1
percent. The health department must be notified if it is suspected that a victim has
cholera.
MD0589
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