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  Table of Contents  
Year : 2013  |  Volume : 31  |  Issue : 2  |  Page : 185-187

Severe diarrhoea due to Cystoisospora belli in renal transplant patient on Immunosuppressive drugs

Pranav Pathology Lab, 102 Sarnag Apt, Near GPO, Raopura, Vadodara, Gujarat, India

Date of Submission03-Dec-2013
Date of Acceptance13-Apr-2013
Date of Web Publication19-Jul-2013

Correspondence Address:
A Marathe
Pranav Pathology Lab, 102 Sarnag Apt, Near GPO, Raopura, Vadodara, Gujarat
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0255-0857.115227

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 ~ Abstract 

Cystoisospora belli , formerly known as Isospora belli, protozoal parasite endemic to many regions of the world including the Caribbean, Central and South America, Africa, and South-East Asia. It is frequently encountered in patients with acquired immunodeficiency syndrome (AIDS) and is considered to be an AIDS-defining illness. Chronic severe watery diarrhoea due to C. belli has also been reported in other immunodeficiency states. C. belli infection in immunosuppressed patients has rarely been described. We describe severe diarrhoea due to C. belli in a human immunodeficiency virus-negative renal transplant recipient on immunosuppressive drugs. Oocysts of C. belli were detected in direct smear preparation of the diarrheic stool sample of the patient. The patient responded to combination treatment with Bactrim-double-strength (trimethoprim-sulfamethoxazole) and Nitazoxanide.

Keywords: Cystoisospora belli, renal transplant, severe diarrhoea

How to cite this article:
Marathe A, Parikh K. Severe diarrhoea due to Cystoisospora belli in renal transplant patient on Immunosuppressive drugs. Indian J Med Microbiol 2013;31:185-7

How to cite this URL:
Marathe A, Parikh K. Severe diarrhoea due to Cystoisospora belli in renal transplant patient on Immunosuppressive drugs. Indian J Med Microbiol [serial online] 2013 [cited 2020 Oct 25];31:185-7. Available from:

 ~ Introduction Top

Cystoisospora belli is a coccidian, unicellular protozoan parasite that resides in the gastrointestinal tract. It is only known to infect humans. The distribution is world-wide, especially in tropical and subtropical areas. Infection occurs by ingestion of sporocysts-containing oocysts.

The three coccidian parasites that most commonly cause clinical disease in human are C. belli, Cryptosporidium parvum, and Cyclospora spp. C. belli primarily causes gastrointestinal disease; typical symptoms include fever, watery diarrhoea, nausea, vomiting, abdominal pain, dehydration, weight loss and headache. [1],[2] Extra-intestinal infections with tissue cyst-like stages have been observed in the mesenteric, periaortic and mediastinal lymph nodes, liver and in the spleen of patients with acquired immunodeficiency syndrome (AIDS) [3],[4] and probably also occur in immune competent patients.

The diagnosis of intestinal cystoisosporiasis requires identification of the characteristic oocysts in a stool sample. The most common techniques used on stool samples include wet mount examination, modified acid-fast stain or Safranin stain.

C. belli infection in immunosuppressed patients has rarely been described; this is to our knowledge, the first report of C. belli infection as a cause of severe diarrhoea in a human immunodeficiency virus (HIV) negative renal transplant recipient from India.

 ~ Case Report Top

A 50-year-old male presented with diarrhoea and fever to a nephrology clinic. The diarrhoea was described as pale yellow without frank blood. He had a frequency of 8-10 episodes during the day time and 3-5 during night.

The past history revealed that the patient was a renal transplant recipient and his wife was the donor. The patient was on Sirolimus for immune suppression.

He was admitted to the emergency room with an acute onset watery diarrhoea, low-grade fever, and nausea. Haematological investigations did not show any significant abnormality. Biochemical laboratory tests indicated Blood urea 44 mg/dl, serum creatinine of 2.3 mg/dl, serum alanine transaminase ALT was 22 IU/L, serum sodium 129 mEq/L and potassium 3.4 mEq/L. He was also tested for HIV, and results were negative with enzyme linked immunosorbent assay (ELISA) method. The patient had no travel history to foreign countries.

The stool was brownish and liquid in consistency with mucus flakes, the pH was 7.5 and occult blood was strongly positive. As seen in [Figure 1] the unsporulated Cystoisospora oocysts appeared elliptical in shape, with one or both ends slightly tapered.
Figure 1: The unsporulated Cystoisospora

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The C. belli unsporulated oocysts measured 29.1 um × 15.7 um in size, Oocysts with one sporoblast seen in [Figure 2], measured 28.1 um × 13.2 um and with two sporoblast as seen in [Figure 3] measured 32.7 × 12.7. Characteristically most of the parasitic stages were with one or two sporoblasts and rarely there were immature forms. In HIV positive patients mostly immature forms are seen.
Figure 2: Oocysts with one sporoblast

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Figure 3: Oocyst with two sporoblast

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Complete improvement of the patient was achieved after combination treatment with (160 mg of trimethoprim and 800 mg of sulfamethoxazole) of one double-strength (DS) tablet bid orally co-trimoxaxzole TMP-SMX-DS and Nitazoxanide 600 mg daily for 7 days.

Repeat stool examination on 10 th day did not show the presence of C. belli oocysts even after concentration.

 ~ Discussion Top

C. belli is distributed world-wide particularly endemic in tropical and subtropical regions but has been infrequently detected in stool specimens. Although the infection frequently occurs in the immunocompromised patient, it can also cause disease in adults and children. The parasite may cause acute self-limiting diarrhoea, fever and abdominal pain that usually resolve spontaneously in a normal host. In severely immunosuppressed patients, severe chronic diarrhoea is often reported and has been associated with fulminant diarrhoea leading to a wasting syndrome and sometimes death in AIDS patients. [5]

Cystoisosporiasis has also been observed in patients with concurrent Hodgkin's disease, non-Hodgkin's lymphoproliferative disease, human T-cell leukaemia virus type 1 - associated adult T-cell leukaemia, and acute lymphoblastic leukaemia. [6] C. belli has been observed in liver transplant patients. [7] A case of C. belli infection was also reported in a patient with sickle-cell anaemia. [8]

Although, the distribution of C. belli is world-wide. [9] It is rarely reported from most countries including India. To our knowledge, this is the first reported case of C. belli infection of a renal transplant recipient in India. The detection of human intestinal coccidian parasites depends on the thorough examination of Concentrated stool specimens. In conclusion, cystisosporiasis should be suspected in immunocompromised patients, transplant patients and those infected with HIV, with severe diarrhoea, abdominal cramps and weight loss. Also TMP-SMX could be the drug of choice in patients C. belli infection. Early diagnosis and prompt therapy would save the patient from consequences of C. belli infection such as malabsorption and weight loss.

 ~ References Top

1.DeHovitz JA, Pape JW, Boncy M, Johnson WD Jr. Clinical manifestations and therapy of Isospora belli infection in patients with the acquired immunodeficiency syndrome. N Engl J Med 1986;315:87-90.  Back to cited text no. 1
2.Kaplan JE, Benson C, Holmes KH, Brooks JT, Pau A, Masur H, et al. Guidelines for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: Recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. MMWR Recomm Rep 2009;58:1-207.  Back to cited text no. 2
3.Lindsay DS, Dubey JP, Toivio-Kinnucan MA, Michiels JF, Blagburn BL. Examination of extraintestinal tissue cysts of Isospora belli. J Parasitol 1997;83:620-5.  Back to cited text no. 3
4.Restrepo C, Macher AM, Radany EH. Disseminated extraintestinal isosporiasis in a patient with acquired immune deficiency syndrome. Am J Clin Pathol 1987;87:536-42.  Back to cited text no. 4
5.Certad G, Arenas-Pinto A, Pocaterra L, Ferrara G, Castro J, Bello A, et al. Isosporiasis in Venezuelan adults infected with human immunodeficiency virus: Clinical characterization. Am J Trop Med Hyg 2003;69:217-22.  Back to cited text no. 5
6.Atambay M, Bayraktar MR, Kayabas U, Yilmaz S, Bayindir Y. A rare diarrheic parasite in a liver transplant patient: Isospora belli. Transplant Proc 2007;39:1693-5.  Back to cited text no. 6
7.Mahdi NK, Ali NH. Intestinal parasites, including Cryptosporidium species, in Iraqi patients with sickle-cell anaemia. East Mediterr Health J 2002;8:345-9.  Back to cited text no. 7
8.Büyükbaba-Boral O, Uysal H, Alan S, Büget E, Nazlýcan Ö. AIDS'li bir hastada belirlenen izosporiyaz olgusu. Turk Mikrobiyol Cem Derg 2005;35:45-9.  Back to cited text no. 8
9.Kýlýç H, Sümerkan B, Koç AN, Ünal A, Sehmen E. Bronkoalveolar karsinomlu bir olguda Isospora belli. Mirobiyol Bult 1995;29:410-3.  Back to cited text no. 9


  [Figure 1], [Figure 2], [Figure 3]


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