Interview with Dr. Mikhail Agapov on “Balantidiasis in a Patient with Suspected Crohn’s Disease.” Endoscopy. 2006 Mar 3.


1. Which are the methods to treat the disease? How effective are they? And how do they work?

The disease is treated with metranidasol, or tetraciclin for 5-10 days;
some authors recommend repeating such courses 2-3 times in 5 days interval.
The treatment is usually effective, but without antibiotics mortality level
approaches 10-12 % (up to 30 % in fulminate disease). The disease is
especially dangerous in immunocompromised patients as pulmonary parenchyma
involvement is possible.

2. What is the best treatment if there is one and why?

As far as I know all mentioned medicines are equally effective and which
to choose depends on patients history of drug intolerance, possible side
effects and doctor’s own preferences. It is not quite clear why tetracycline
has failed in the presented case; suboptimal dose of the drug or lack of
patient’s compliance might be the possible reasons for it.

3. In the patient with suspected Crohn's disease, why did you stop the tetracycline and put him on metronidazole?

In this case tetracycline was started by family physician for suspected
infectious diarrhea. The treatment did lead to some improvement – decrease
in the number of bowel movements, but symptoms failed to be resoled
completely, more over the patient developed rectal bleeding while on it.
Tetracycline was stopped when Crohn's disease was suspected (it is
completely ineffective in IBD). Metranidasol was started after BALANTIDIUM
COLI had been detected on morphologic examination. So the patient had
several days gap between tetracycline and metranidasol. We decided to
utilize metranidasol as previous treatment with tetracycline had only modest

4. What are some other methods to prevent or control the spread of the disease? Is human to human transmission possible?  If so, why is it that the prevalence is so low?  It would seem that since there are asymptomatic patients and various reservoirs, the disease would be more prevalent in places of poor sanitation where fecal-oral transmission could occur. 

The main hosts of the BALANTIDIUM are pigs. For them the prevalence
of the infection is estimated as high as 80-100 % (pigs are asymptomatic
carriers).    Human to human transmission is possible, but very rare.  The
following article may be of interest for you - Young MD: Attempts to
transmit human Balantidium coli. Am J Trop Med Hyg 1950 Jan; 30(1): 71.
People infected with BALANTIDIUM are often asymptomatic and it’s true
prevalence in population is difficult to estimate.  Fecal-oral transmission
is the only root for the infection (in warm and whet climate BALANTIDIUM may
survive for a long time in contaminated soil and water). So hygienic
measures is the main way of prophylactic. Poor nutrition, immunosuppression
and achlorhydria are the possible factors associated with clinically
pronounced disease.

5. What is the best way to diagnose this?  Since this is a rare disease, what would make you suspect this in a patient?

There is only one way to establish definite diagnosis of balantadiasis –
to detect BALANTIDIUM COLI in the specimens taken from the ulcer margins in
the large bowel or in fezzes. BALANTIDIUM COLI does not stain well on
permanent stained smears, but diagnosis can be made by examining wet smears
of stool specimens (usually under low power as it moves fast). The clinical
and endoscopic picture of the disease has a lot of overlapping features with
other infectious colitis and IBD. Diarrhoea (watery, bloody, mucoid),
abdominal pain, nausea and vomiting, weight loss, headache and abdominal
tenderness without rebound are the main symptoms.    Morphologic examination
is a standard procedure to confirm diagnosis for patients with various
pathology of the large bowel.  I must confess that we did not suspect
balantadiasis in the case before  BALANTIDIUM COLI had been detected. Anyway
one should be aware of the disease, especially when the patient has contact
with pigs, handles fertilizer contaminated with pig excrement, or lives in
areas where the water supply may be contaminated by the excrement of
infected animals.