eMedicine Specialties > Infectious Diseases > Parasitic Infections

Balantidiasis

Valda M Chijide, MD, Clinical Professor, Department of Medicine, University of Saskatchewan; Consultant in Infectious Diseases, Regina, Saskatchewan, Canada

Updated: Sep 18, 2008

Introduction

Background

Balantidiasis (also known as balantidiosis) is defined as large-intestinal infection with Balantidium coli, which is a ciliated protozoan (and the largest protozoan that infects humans). B coli is known to parasitize the colon, and pigs may be its primary reservoir.

Pathophysiology

B coli exists as a trophozoite and a cyst and usually affects the large intestine, from the caecum to the rectum. The trophozoites replicate by binary fission and conjugation, and they subsist on bacteria. Humans ingest infective cysts, which then migrate to the large intestine, cecum, and terminal ileum. The organisms primarily dwell in the lumen but can also penetrate the mucosa and cause ulcers. B coli produces hyaluronidase, potentially enhancing its ability to invade the mucosa.

Frequency

United States

Balantidiasis is found worldwide and has an overall estimated prevalence of 1%. Balantidiasis epidemics have occurred in psychiatric hospitals in the United States.

International

Balantidiasis tends to be more common among persons who handle pigs. The disease is reported most commonly in Latin America; Southeast Asia; and Papua, New Guinea. In 1971, a balantidiasis outbreak involving 100 people occurred in Truk following a typhoon.¹  In France, a pork butcher with immunosuppression due to alcohol use developed occupational balantidiasis.²

Mortality/Morbidity

Most cases of balantidiasis in immunocompetent individuals are asymptomatic. Mortality rates associated with acute and fulminating types of balantidiasis were as high as 30% in untreated patients prior to the introduction of antibiotics. Pneumonia has been described in patients with cancer-related immunosuppression³ and has not always been associated with direct contact with pigs.

Clinical

History

Potential symptoms of balantidiasis include the following:

• Diarrhea (watery, bloody, mucoid)
• Nausea
• Vomiting
• Abdominal pain
• Anorexia
• Weight loss
• Headache
• Mild colitis
• Fever
• Severe and marked fluid loss (resembling amebic dysentery)

Physical

Patients with balantidiasis may present with abdominal tenderness, fever, and prolonged diarrhea, which may result in signs of dehydration.

Causes

Risk factors for balantidiasis include contact with pigs, handling fertilizer contaminated with pig excrement, and living in areas where the water supply may be contaminated by the excrement of infected animals. Poor nutrition, achlorhydria, alcoholism, and immunosuppression may also be contributing factors.

Differential Diagnoses

Pneumonia, Fungal

Other Problems to Be Considered

Peritonitis

Workup

Laboratory Studies

• Wet smear stool specimens
  • B coli does not stain well on permanent stained smears, complicating diagnosis of balantidiasis; however, the diagnosis can be made by examining wet smears of stool specimens or scrapings from the periphery of ulcers during an endoscopic examination.
  • On unstained specimens, the trophozoite is recognized by its large size (approximately 50-100 µm in length and 40-70 µm in width), a short ciliary covering, and its spiraling motility. It is frequently observed under low power. On stained preparations, the trophozoite characteristically shows 2 nuclei: the macronucleus, which is kidney-shaped, and the micronucleus, which is spherical and lies close to the macronucleus.
  • Cysts may be spherical or ellipsoid and are approximately 50-70 µm long. Newly encysted organisms observed on unstained specimens may still have cilia, but cilia disappear after a longer period of encystment. Observation of a macronucleus and a micronucleus is diagnostic if observed in a cyst on a stained specimen.

Imaging Studies

• Chest radiography may show pulmonary parenchymal involvement in patients with balantidiasis.
• Computed tomography (CT) scanning may reveal pulmonary parenchymal and lymph node involvement, as well as involvement of other organ systems.

Procedures

• Colonoscopy: Perform an endoscopic examination of the colon to obtain a biopsy of ulcers, thereby aiding in diagnosis of balantidiasis. Obtain the specimens from the periphery of ulcers.
• Bronchoalveolar lavage (BAL) can identify organisms on wet mount of bronchial secretions.

Histologic Findings

B coli can invade the mucosa and submucosa, causing ulceration and infiltration with polymorphonuclear cells, lymphocytes, and eosinophils. Trophozoites can be observed at the invading edge of ulcers or at the periphery of submucosal abscesses.

Treatment

Medical Care

Special attention should be paid to volume replacement and electrolyte repletion in patients with balantidiasis who have severe diarrhea.

Surgical Care

Balantidiasis rarely manifests as acute appendicitis, which requires appendectomy.⁴

Consultations

• Consult a surgeon for management of acute abdomen problems (eg, appendectomy, laparotomy).
• Consult a gastroenterologist for patients who require colonoscopy.
• Therapy in an intensive care unit may be required for patients with balantidiasis who show signs of clinical deterioration despite receipt of appropriate antibiotics.

Medication

The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Prolonged courses of therapy may be required to cure balantidiasis in patients who are infected with HIV or who are otherwise immunosuppressed.

Antibiotics

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting. Tetracycline is the treatment of choice, with metronidazole being the primary alternative. Iodoquinol, puromycin, and nitazoxanide are also effective against balantidiasis.

Tetracycline (Sumycin)

Isolated from a strain of Streptomyces aureofaciens. Exerts a bacteriostatic effect by reversibly binding to 30S and 50S ribosomal subunits of susceptible organisms, thereby inhibiting protein synthesis.

Dosing

Adult

500 mg PO qid for 10 d

Pediatric

<8 years: Not recommended
>8 years: 40 mg/kg/d PO divided qid for 10 d; not to exceed 2 g/d PO

Interactions

Decreases effect of penicillin; colestipol, divalent/trivalent cation–containing antacids, food, dairy products, and supplements decrease absorption; increases anticoagulant effect of warfarin; decreases efficacy of oral contraceptives; increases serum levels of digoxin and lithium; concurrent use of retinoids can increase risk of pseudotumor cerebri; tetracyclines may reduce insulin requirements

Contraindications

Documented hypersensitivity; breastfeeding; children <8 y; renal or hepatic impairment

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Photosensitivity may occur with prolonged exposure to sunlight or tanning equipment; reduce dose in renal impairment; consider drug serum level determinations in prolonged therapy; tetracycline use during tooth development (last half of pregnancy through age 8 y) can cause permanent discoloration of teeth; Fanconi-like syndrome may occur with outdated tetracycline; some patients experience headache, light-headedness, dizziness, or vertigo

Metronidazole (Flagyl)

Synthetic drug with antiprotozoal and antibacterial action used to treat symptomatic patients with diarrhea.

Dosing

Adult

500 mg PO tid for 5 d

Pediatric

35-50 mg/kg/d PO divided tid for 5 d

Interactions

Alcohol intake during and for 3 d after therapy induces disulfiramlike reaction; microsomal enzyme inducers (eg, phenytoin, phenobarbital) decrease serum levels; microsomal enzyme inhibitors (eg, cimetidine) prolong half-life; increases serum lithium levels and/or lithium toxicity

Contraindications

Documented hypersensitivity to metronidazole or other nitroimidazole derivatives; first trimester of pregnancy; history of blood dyscrasias

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in hepatic disease; monitor for seizures and development of peripheral neuropathy

Iodoquinol (Yodoxin)

Contact amebicide works in the lumen of intestine.

Dosing

Adult

650 mg PO tid for 20 d

Pediatric

40 mg/kg/d PO divided tid for 20 d

Interactions

Increases protein-bound serum iodine concentration

Contraindications

Documented sensitivity; hepatic insufficiency; iodine intolerance

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

GI distress, acneform and bullous eruptions, optic neuritis, optic atrophy, peripheral neuropathy, and thyroid dysfunction may occur; avoid long-term therapy

Follow-up

Further Outpatient Care

• Patients with balantidiasis should have a follow-up visit after treatment to document the resolution of symptoms. Also, obtain a stool specimen and a wet smear to check for organisms.

Deterrence/Prevention

• A clean water supply and hygienic living conditions can prevent balantidiasis.
• Avoiding contact with pigs and fertilizer that is contaminated with pig excrement can decrease the risk of balantidiasis.

Complications

• Intestinal perforation and extraintestinal spread to liver and mesenteric lymph nodes are rare.
• Pulmonary involvement has been reported and appears to be more common in patients with underlying illnesses such as diabetes, cancer, or impaired lymphocyte function.

Prognosis

• In the antibiotic era, severe balantidiasis carries an improved prognosis, and most affected patients now recover.

Patient Education

• Patients should be counseled on the importance of good handwashing, particularly after being exposed to environments where likelihood of infection is high.

Miscellaneous

Special Concerns

• Immediately examine a stool sample because the trophozoites do not survive long outside of the colon.
• Patients with balantidiasis who are infected with HIV may require up to 30 days of therapy for a cure.

Multimedia

Media file 1: Trophozoite of Balantidium coli in colon. This photograph shows the large macronucleus and the thin cell membrane covered with cilia (X820). Courtesy of Armed Forces Institute of Pathology (AFIP 75-9300).

Media file 2: Cyst of Balantidium coli in feces. This photograph demonstrates a thick cyst wall and a large macronucleus (X820). Courtesy Armed Forces Institute of Pathology (AFIP 75-9301).

References

1. Walzer PD, Judson FN, Murphy KB, et al. Balantidiasis outbreak in Truk. Am J Trop Med Hyg. Jan 1973;22(1):33-41. [Medline].

2. Ferry T, Bouhour D, De Monbrison F, et al. Severe peritonitis due to Balantidium coli acquired in France. Eur J Clin Microbiol Infect Dis. May 2004;23(5):393-5. [Medline].

3. Vasilakopoulou A, Dimarongona K, Samakovli A, et al. Balantidium coli pneumonia in an immunocompromised patient. Scand J Infect Dis. 2003;35(2):144-6. [Medline].

4. Dodd LG. Balantidium coli infestation as a cause of acute appendicitis. J Infect Dis. Jun 1991;163(6):1392. [Medline].

5. Anargyrou K, Petrikkos GL, Suller MT, et al. Pulmonary Balantidium coli infection in a leukemic patient. Am J Hematol. Jul 2003;73(3):180-3. [Medline].

6. Arean VM, Koppisch E. Balantidiasis; a review and report of cases. Am J Pathol. Nov-Dec 1956;32(6):1089-115. [Medline].

7. Aucott JN, Ravdin JI. Amebiasis and "nonpathogenic" intestinal protozoa. Infect Dis Clin North Am. Sep 1993;7(3):467-85. [Medline].

8. Canadian Pharmacists Association. Compendium of Pharmaceuticals and Specialties (CPS). 2006;2182-2183.

9. Esteban JG, Aguirre C, Angles R, et al. Balantidiasis in Aymara children from the northern Bolivian Altiplano. Am J Trop Med Hyg. Dec 1998;59(6):922-7. [Medline].

10. Fisk T, Keystone J, Kozarsky P. Cyclospora cayetanensis, Isospora belli, Sarcocystis Species, Balantidium coli, and Blastocystis hominis. In: Mandell GL, Bennet JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 2. 6^th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2005:3228-37.

11. Garcia L, Bruckner D. Intestinal Protozoa: Flagellates and Ciliates. In: Diagnostic Medical Parasitology. 3^rd ed. Washington, DC: ASM Press; 1997:34-53.

12. Markell E. Lumen-Dwelling Protozoa. In: Markell and Voge's Medical Parasitology. 8^th ed. Philadelphia, Pa: WB Saunders Co; 1999:24-89.

13. Micromedex. Tetracycline. Drugdex Drug Evaluations. 2000. Available at: http://www.micromedex.com:Accessed 2000. [Medline].

14. Neafie R. Balantidiasis. In: Pathology of Tropical and Extraordinary Diseases. Vol 1. Washington, DC: Armed Forces Institute of Pathology; 1976:325-7.

15. PDR. Physicians' Desk Reference. Montvale, NJ: Medical Economics Company, Inc; 2000.

16. Rosenblatt JE. Antiparasitic agents. Mayo Clin Proc. Nov 1999;74(11):1161-75. [Medline].

17. The Medical letter on drugs and therapeutics. Drugs for parasitic infections. Med Lett Drugs Ther. Jan 2 1998;40(1017):1-12. [Medline].

18. Yazar S, Altuntas F, Sahin I, et al. Dysentery caused by Balantidium coli in a patient with non-Hodgkin's lymphoma from Turkey. World J Gastroenterol. Feb 1 2004;10(3):458-9. [Medline].

19. Young MD. Attempts to transmit human Balantidium coli. Am J Trop Med Hyg. Jan 1950;30(1):71. [Medline].

Keywords

balantidiasis, balantidiosis, Balantidium coli, B coli, hyaluronidase, Balantidium coli infection, B coli infection, acute balantidiasis, fulminating balantidiasis, occupational balantidiasis, protozoa infection, protozoan infection, colon cyst, colonic cyst

Contributor Information and Disclosures

Author

Valda M Chijide, MD, Clinical Professor, Department of Medicine, University of Saskatchewan; Consultant in Infectious Diseases, Regina, Saskatchewan, Canada
Valda M Chijide, MD is a member of the following medical societies: American College of Physicians, HIV Medicine Association of America, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Medical Editor

Jeffrey D Band, MD, Clinical Professor of Medicine, Wayne State University School of Medicine; Director, Division of Infectious Diseases and International Medicine, William Beaumont Hospital Corporation
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Ronald A Greenfield, MD, Professor, Department of Internal Medicine, Section of Infectious Diseases, University of Oklahoma College of Medicine
Ronald A Greenfield, MD is a member of the following medical societies: American College of Physicians, American Federation for Medical Research, American Society for Microbiology, Central Society for Clinical Research, Infectious Diseases Society of America, Medical Mycology Society of the Americas, Phi Beta Kappa, Southern Society for Clinical Investigation, and Southwestern Association of Clinical Microbiology
Disclosure: Pfizer Honoraria Speaking and teaching; Gilead Honoraria Speaking and teaching; Ortho McNeil Honoraria Speaking and teaching; Wyeth Honoraria Speaking and teaching; Abbott Honoraria Speaking and teaching; Astellas Honoraria Speaking and teaching; Cubist  Speaking and teaching

CME Editor

Eleftherios Mylonakis, MD, Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital
Eleftherios Mylonakis, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital
Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

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