Refractory Isosporiasis
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《美国医学杂志》
1 Departments of Microbiology and Pediatrics, All India Institute of Medical Sciences, New Delhi, India
2 Departments of Microbiology and 1Pediatrics, All India Institute of Medical Sciences, New Delhi, India, India
Abstract
Abstract. The authors describe a case of severe debilitating diarrhea due to isosporiasis in a two year old child, a known case of systemic vasculitis receiving prolonged corticosteroids therapy , an association rarely reported previously. It was refractory to treatment with dihydrofolate reductase inhibitor combined with sulfonamide such as cotrimoxazole to which isosporiasis usually responds well and is being described here for clinical interest and uniqueness of its presentation and laboratory findings. [Indian J Pediatr 2005; 72 (5) : -439]
Keywords: Isosporiasis; Steroids; Recurrence
Isosporiasis is a diarrheal illness caused in humans by Isospora belli and is cosmopolitan in distribution; although more common in southeast Asia, Africa, and parts of South America.[1] It produces self limiting watery diarrhea in immunocompetent hosts and chronic severe debilitating watery diarrhea in immunocompromised patients. [2] Opportunistic isosporidial infection of the gastrointestinal tract is frequently encountered in AIDS patients and is considered an AIDS defining illness.[3] Besides AIDS, chronic severe watery diarrhea due to Isospora belli has also been reported in other immunodeficiency states.[1] We describe here severe debilitating diarrhea due to isosporiasis in a patient receiving prolonged corticosteroids therapy, an association rarely reported previously, which was refractory to treatment with dihydrofolate reductase inhibitor combined with sulfonamide such as cotrimoxazole to which isosporiasis usually responds well.
Case Report
0The patient, a two year child , who was on tapering steroid therapy (receiving 7.5 mg/day prednisolone at that time) since eight months and oral cyclophosphamide (2-3 mg/kg/day), was admitted to pediatrics ward with history of sudden onset severe watery diarrhea of one week duration. The child was a known case of systemic vasculitis. The stools were watery in consistency with a frequency of 15-20 episodes per day. He also had associated low grade fever with productive cough for the last one week as well as oral thrush. The child was grossly malnourished ( PEM grade III). Laboratory examination showed Hb 13.1gm%, TLC 5300/mm3 (N 64%, L-28%,
E-8%), SGOT 51U/L, SGPT 56U/L, Alkaline phosphatase 96U/L, Blood urea 14 mg/dl, Serum creatinine 0.5 mg/dl, total bilirubin 0.7 mg/dl, Uric acid 2.2mg/dl. Serology was negative for antinuclear and antineutrophilic cytoplasmic antibodies. His immunoglobulin profile was within normal range. The patient's serum was negative for anti-HIV antibodies by ELISA and his CD4 and CD8 counts were 330/ml and 544/ml respectively. His stool sample was sent to rule out any parasitological etiology.
The stool was watery in consistency with visible shreds of mucous membrane. A direct wet saline and an iodine mount were prepared from the stool sample with an effort to include part of mucous shred in the sampling. Direct wet mount examination revealed large numbers of epithelial cells, pus cells (30-40/HPF, mainly eosinophils), numerous Charcoat-Leyden crystals(10-15/HPF) and red blood cells (5-10/HPF). Oocysts of Isospora belli , (predominantly immature) intermingled within the mucous membrane were seen in an overwhelmingly high number (approximately 20-25/HPF). They were long and oval, measuring 20-31 m ×11-19 m on micrometry. Also seen on wet mount (400X) were some banana shaped curved structures (5-7/HPF) with one end more rounded than the other and measuring 10-13 × 4-5 m in size. On the basis of characteristic morphology and size[4], these structures were identified to be merozoites of Isospora (Fig. 1). Modified Ziehl-Neelsen staining technique[5] revealed Isospora oocysts (Fig. 2) many of which were partially stained and some unstained. Bacterial culture of the stool performed as per standard protocols[6] did not grow any pathogenic bacteria. Stool was not examined for any pathogenic viruses.
The child was treated with oral cotrimoxazole (Trimethoprim 20 mg/kg/day and sulphamethoxazole 100 mg/kg/day) for 10 days. The diarrhoea ceased within three days and the patient's subsequent stool sample after a period of seven days did not reveal any Isospora oocyst. The child gained weight and was discharged after eight days of stay in hospital. Three weeks later, the child again developed an episode of acute diarrhoea, which was also confirmed to be due to Isospora , and it responded to cotrimoxazole with stool becoming negative for Isospora oocysts. He later developed four recurrences of isosporiasis and was prescribed prolonged cotrimoxazole prophylactic therapy. However, cotrimoxazole had to be discontinued due to drug reaction and the parents of the child abandoned the treatment and switched to alternate system of medicine (ayurvedic therapy). The child continued to have diarrheal episodes and eventually died of severe malnutrition and hepatic failure ( severe jaundice) as revealed by parents later.
Discussion
Isosporiasis has been commonly reported in immunocompromised patients with AIDS. It has also been observed in patients with Hodgkin's disease , non Hodgkin's lymphoproliferative disease or acute lymphoblastic leukaemia.[1] Only once previously has it been described in association with steroid use. Morakote et al reported a case of acute isosporiasis from Thailand in a patient with underlying Nephrotic syndrome, who had received prednisolone 60mg/day for 13 days.[7] The patient recovered from diarrhoea without any specific treatment.
There are several remarkable features in the present case, which make it unique. This patient not only had severe diarrhoea due to Isospora , he had recurrent episodes of isosporiasis, a phenomenon usually observed in severely immunodeficient AIDS patients with CD4 counts <200/mm3. [2,8] In this patient, merozoites of Isospora belli were demonstrated in routine wet mount stool microscopy along with Isospora ooysts. These merozoites are formed after the process of schizogony occurring in the mucosal cells of the intestine. [4,5] Usually, these merozoites are demonstrable only on an intestinal biopsy, where they are seen inside the mucosal epithelial cells[4], while Isospora oocysts are shed in the stool and examination of these oocysts in stool is the recommended method for the diagnosis isosporiasis.[1] Shedding of Isospora merozoites in stool, to the best of our knowledge has not been reported earlier. Presence of a large number of merozoites of Isospora in the stool is indicative of a severe inflammation/injury to the intestinal mucosa, which is also substantiated in this case by the presence in stool of visible mucosal shreds, large number of pus cells, red blood cells and epithelial cells as well as occult blood positivity of stool. This is unlike of isosporiasis, which is characterized by watery diarrhoea associated with fever without blood or leukocytes. [1,9] The intestinal mucosal injury in this patient seems most likely to be due to small vessel vasculitis involving the intestine, the patient's primary illness. Presence of numerous Isospora oocysts in stool (20-25/HPF) is another remarkable feature of this case. This is also unlike most of the previous reports on isosporiasis including in AIDS patients with severe immunodeficiency in whom only few oocysts could be demonstrable. Majority of oocysts seen in the stool in this case were immature, and devoid of sporoblasts/sporocysts, which explains the presence of partially stained or unstained oocysts (Fig. 2) on acid fast staining.[10
]The reasons for recurrences of isosporiasis could not be clear. These episodes were unlikely to be due to drug resistance in this case as each time diarrhea responded to cotrimoxazole clinically as well as microbiologically (stool becoming negative for Isospora oocysts) with recurrence occurring only after a gap of few weeks. The recurrent episodes of isosporiasis occuring in such quick succession could also not be explained due to reinfection from an exogenous source in the family since the hygiene of the child was taken good care of. Besides, no episodes of diarrhea were reported in the family during that period. Reactivation of any endogenous extraintestinal foci of Isospora existing in the form of a tissue cyst therapy, which did not get eradicated during oral cotrimoxazole could be a possibility. Tissue cysts containing merozoites of Isospora belli have been demonstrated in intestinal lamina propria, lymphatic channels, paraaortic, mesenteric and mediastinal nodes and as far as liver, spleen and gall bladder of AIDS patients. [9, 11, 12] These extraintestinal tissue cysts may represent a reservoir of developmental stages that can recolonise the intestine and cause recrudescence of clinical disease.[11] An association between CMV induced intestinal mucosal ulceration and dissemination of microorganisms commonly restricted to the intestinal tract has been frequently observed in profoundly immunosuppressed AIDS patients.[9] There is a possibility that in this case too, a mucosal injury favoured isospora infection to become invasive and the weak defences of the child helped localize it in some extraintestinal site.
Contributions of Authors
Data analysis and drafting of manuscript was done by Dr. Sonia Malik. Dr. J.C. Samantaray and Dr. Arvind Bagga contributed to critical revision of the manuscript for improvement of its intellectual content. Dr. Anupam Das contributed to collection of patient data, literature search and technical help.
Conflict of interest : None declared
Funding Source : None other than departmental fundin
References
1. Lindsay DS, Dubey JP, Blagburn BL. Biology of Isospora spp . from humans, nonhuman primates and domestic animals . Clin Microbiol Rev 1997;10: 19-34.
2. DeHovitz JA, Pape JW, Boncy M, Johnson WD Jr. Clinical manifestations and therapy of Isospora belli infection in patients with acquired immunodeficiency syndrome . N Engl J Med 1986; 315 : 87-90.
3. Centers for Disease Control: Revision of the case definition of acquired immunodeficiency syndrome for national reporting -United States. MMWR Morb Mortal Wkly Rep 1985; 34: 373-375.
4. Field AS. Light microscopic and electron microscopic diagnosis of gastrointestinal opportunistic infections in HIV- positive patients. Pathology 2002; 34 : 21-35
5. Garcia LS, Bruckner DA, eds. Diagnostic Medical Parasitology . 4th ed. Washington DC: ASM Press; 1997; 54-89.
6. Collee JG, Fraser AG, Marmion BP, Simmons A, eds. Mackie & Mc Cartnery Practical Medical Microbiology. 14th edn. Churchill Livingstone; 1996.
7. Morakote N, Muangyimpong Y, Somboon P, Khamboonruang C. Acute human Isosporiasis in Thailand: A case report. Southeast Asian J Trop Med Public Health 1987; 18 : 107-111.
8. Pape JW, Verdier RI, Johnson WD. Treatment and prophylaxis of Isospora belli infection in patients with the acquired immunodeficiency syndrome . N Engl J Med 1989;320:1044 -1047.
9. Restrepo C, Macher AM, Radany EH. Disseminated extraintestinal Isosporiasis in a patient with Acquired immunodeficiency syndrome . Am J Clin Path 1987; 87 : 536-542
10. Markell EK, John DT, Krotoski WA, eds. Markell and Voge's Medical Parasitology. 8th edn. Philadelphia; Pennsylvania; W.B. Saunder's Company; 1999; 24-89.
11. Lindsay DS, Dubey JP, Toiviokinnucan MA, Michiels JF, Blagburn BL. Examination of extraintestinal tissue cysts of Isospora belli . J Parasitol 1997; 83:620-625.
12. Benator DA, French AL, Beaudet LM, Levy CS, Orenstein JM. Isospora belli infection associated with acalculous cholecyctitis in a patient with AIDS . Ann Intern Med 1994; 121 : 663-664(Malik Sonia, Samantaray J)
2 Departments of Microbiology and 1Pediatrics, All India Institute of Medical Sciences, New Delhi, India, India
Abstract
Abstract. The authors describe a case of severe debilitating diarrhea due to isosporiasis in a two year old child, a known case of systemic vasculitis receiving prolonged corticosteroids therapy , an association rarely reported previously. It was refractory to treatment with dihydrofolate reductase inhibitor combined with sulfonamide such as cotrimoxazole to which isosporiasis usually responds well and is being described here for clinical interest and uniqueness of its presentation and laboratory findings. [Indian J Pediatr 2005; 72 (5) : -439]
Keywords: Isosporiasis; Steroids; Recurrence
Isosporiasis is a diarrheal illness caused in humans by Isospora belli and is cosmopolitan in distribution; although more common in southeast Asia, Africa, and parts of South America.[1] It produces self limiting watery diarrhea in immunocompetent hosts and chronic severe debilitating watery diarrhea in immunocompromised patients. [2] Opportunistic isosporidial infection of the gastrointestinal tract is frequently encountered in AIDS patients and is considered an AIDS defining illness.[3] Besides AIDS, chronic severe watery diarrhea due to Isospora belli has also been reported in other immunodeficiency states.[1] We describe here severe debilitating diarrhea due to isosporiasis in a patient receiving prolonged corticosteroids therapy, an association rarely reported previously, which was refractory to treatment with dihydrofolate reductase inhibitor combined with sulfonamide such as cotrimoxazole to which isosporiasis usually responds well.
Case Report
0The patient, a two year child , who was on tapering steroid therapy (receiving 7.5 mg/day prednisolone at that time) since eight months and oral cyclophosphamide (2-3 mg/kg/day), was admitted to pediatrics ward with history of sudden onset severe watery diarrhea of one week duration. The child was a known case of systemic vasculitis. The stools were watery in consistency with a frequency of 15-20 episodes per day. He also had associated low grade fever with productive cough for the last one week as well as oral thrush. The child was grossly malnourished ( PEM grade III). Laboratory examination showed Hb 13.1gm%, TLC 5300/mm3 (N 64%, L-28%,
E-8%), SGOT 51U/L, SGPT 56U/L, Alkaline phosphatase 96U/L, Blood urea 14 mg/dl, Serum creatinine 0.5 mg/dl, total bilirubin 0.7 mg/dl, Uric acid 2.2mg/dl. Serology was negative for antinuclear and antineutrophilic cytoplasmic antibodies. His immunoglobulin profile was within normal range. The patient's serum was negative for anti-HIV antibodies by ELISA and his CD4 and CD8 counts were 330/ml and 544/ml respectively. His stool sample was sent to rule out any parasitological etiology.
The stool was watery in consistency with visible shreds of mucous membrane. A direct wet saline and an iodine mount were prepared from the stool sample with an effort to include part of mucous shred in the sampling. Direct wet mount examination revealed large numbers of epithelial cells, pus cells (30-40/HPF, mainly eosinophils), numerous Charcoat-Leyden crystals(10-15/HPF) and red blood cells (5-10/HPF). Oocysts of Isospora belli , (predominantly immature) intermingled within the mucous membrane were seen in an overwhelmingly high number (approximately 20-25/HPF). They were long and oval, measuring 20-31 m ×11-19 m on micrometry. Also seen on wet mount (400X) were some banana shaped curved structures (5-7/HPF) with one end more rounded than the other and measuring 10-13 × 4-5 m in size. On the basis of characteristic morphology and size[4], these structures were identified to be merozoites of Isospora (Fig. 1). Modified Ziehl-Neelsen staining technique[5] revealed Isospora oocysts (Fig. 2) many of which were partially stained and some unstained. Bacterial culture of the stool performed as per standard protocols[6] did not grow any pathogenic bacteria. Stool was not examined for any pathogenic viruses.
The child was treated with oral cotrimoxazole (Trimethoprim 20 mg/kg/day and sulphamethoxazole 100 mg/kg/day) for 10 days. The diarrhoea ceased within three days and the patient's subsequent stool sample after a period of seven days did not reveal any Isospora oocyst. The child gained weight and was discharged after eight days of stay in hospital. Three weeks later, the child again developed an episode of acute diarrhoea, which was also confirmed to be due to Isospora , and it responded to cotrimoxazole with stool becoming negative for Isospora oocysts. He later developed four recurrences of isosporiasis and was prescribed prolonged cotrimoxazole prophylactic therapy. However, cotrimoxazole had to be discontinued due to drug reaction and the parents of the child abandoned the treatment and switched to alternate system of medicine (ayurvedic therapy). The child continued to have diarrheal episodes and eventually died of severe malnutrition and hepatic failure ( severe jaundice) as revealed by parents later.
Discussion
Isosporiasis has been commonly reported in immunocompromised patients with AIDS. It has also been observed in patients with Hodgkin's disease , non Hodgkin's lymphoproliferative disease or acute lymphoblastic leukaemia.[1] Only once previously has it been described in association with steroid use. Morakote et al reported a case of acute isosporiasis from Thailand in a patient with underlying Nephrotic syndrome, who had received prednisolone 60mg/day for 13 days.[7] The patient recovered from diarrhoea without any specific treatment.
There are several remarkable features in the present case, which make it unique. This patient not only had severe diarrhoea due to Isospora , he had recurrent episodes of isosporiasis, a phenomenon usually observed in severely immunodeficient AIDS patients with CD4 counts <200/mm3. [2,8] In this patient, merozoites of Isospora belli were demonstrated in routine wet mount stool microscopy along with Isospora ooysts. These merozoites are formed after the process of schizogony occurring in the mucosal cells of the intestine. [4,5] Usually, these merozoites are demonstrable only on an intestinal biopsy, where they are seen inside the mucosal epithelial cells[4], while Isospora oocysts are shed in the stool and examination of these oocysts in stool is the recommended method for the diagnosis isosporiasis.[1] Shedding of Isospora merozoites in stool, to the best of our knowledge has not been reported earlier. Presence of a large number of merozoites of Isospora in the stool is indicative of a severe inflammation/injury to the intestinal mucosa, which is also substantiated in this case by the presence in stool of visible mucosal shreds, large number of pus cells, red blood cells and epithelial cells as well as occult blood positivity of stool. This is unlike of isosporiasis, which is characterized by watery diarrhoea associated with fever without blood or leukocytes. [1,9] The intestinal mucosal injury in this patient seems most likely to be due to small vessel vasculitis involving the intestine, the patient's primary illness. Presence of numerous Isospora oocysts in stool (20-25/HPF) is another remarkable feature of this case. This is also unlike most of the previous reports on isosporiasis including in AIDS patients with severe immunodeficiency in whom only few oocysts could be demonstrable. Majority of oocysts seen in the stool in this case were immature, and devoid of sporoblasts/sporocysts, which explains the presence of partially stained or unstained oocysts (Fig. 2) on acid fast staining.[10
]The reasons for recurrences of isosporiasis could not be clear. These episodes were unlikely to be due to drug resistance in this case as each time diarrhea responded to cotrimoxazole clinically as well as microbiologically (stool becoming negative for Isospora oocysts) with recurrence occurring only after a gap of few weeks. The recurrent episodes of isosporiasis occuring in such quick succession could also not be explained due to reinfection from an exogenous source in the family since the hygiene of the child was taken good care of. Besides, no episodes of diarrhea were reported in the family during that period. Reactivation of any endogenous extraintestinal foci of Isospora existing in the form of a tissue cyst therapy, which did not get eradicated during oral cotrimoxazole could be a possibility. Tissue cysts containing merozoites of Isospora belli have been demonstrated in intestinal lamina propria, lymphatic channels, paraaortic, mesenteric and mediastinal nodes and as far as liver, spleen and gall bladder of AIDS patients. [9, 11, 12] These extraintestinal tissue cysts may represent a reservoir of developmental stages that can recolonise the intestine and cause recrudescence of clinical disease.[11] An association between CMV induced intestinal mucosal ulceration and dissemination of microorganisms commonly restricted to the intestinal tract has been frequently observed in profoundly immunosuppressed AIDS patients.[9] There is a possibility that in this case too, a mucosal injury favoured isospora infection to become invasive and the weak defences of the child helped localize it in some extraintestinal site.
Contributions of Authors
Data analysis and drafting of manuscript was done by Dr. Sonia Malik. Dr. J.C. Samantaray and Dr. Arvind Bagga contributed to critical revision of the manuscript for improvement of its intellectual content. Dr. Anupam Das contributed to collection of patient data, literature search and technical help.
Conflict of interest : None declared
Funding Source : None other than departmental fundin
References
1. Lindsay DS, Dubey JP, Blagburn BL. Biology of Isospora spp . from humans, nonhuman primates and domestic animals . Clin Microbiol Rev 1997;10: 19-34.
2. DeHovitz JA, Pape JW, Boncy M, Johnson WD Jr. Clinical manifestations and therapy of Isospora belli infection in patients with acquired immunodeficiency syndrome . N Engl J Med 1986; 315 : 87-90.
3. Centers for Disease Control: Revision of the case definition of acquired immunodeficiency syndrome for national reporting -United States. MMWR Morb Mortal Wkly Rep 1985; 34: 373-375.
4. Field AS. Light microscopic and electron microscopic diagnosis of gastrointestinal opportunistic infections in HIV- positive patients. Pathology 2002; 34 : 21-35
5. Garcia LS, Bruckner DA, eds. Diagnostic Medical Parasitology . 4th ed. Washington DC: ASM Press; 1997; 54-89.
6. Collee JG, Fraser AG, Marmion BP, Simmons A, eds. Mackie & Mc Cartnery Practical Medical Microbiology. 14th edn. Churchill Livingstone; 1996.
7. Morakote N, Muangyimpong Y, Somboon P, Khamboonruang C. Acute human Isosporiasis in Thailand: A case report. Southeast Asian J Trop Med Public Health 1987; 18 : 107-111.
8. Pape JW, Verdier RI, Johnson WD. Treatment and prophylaxis of Isospora belli infection in patients with the acquired immunodeficiency syndrome . N Engl J Med 1989;320:1044 -1047.
9. Restrepo C, Macher AM, Radany EH. Disseminated extraintestinal Isosporiasis in a patient with Acquired immunodeficiency syndrome . Am J Clin Path 1987; 87 : 536-542
10. Markell EK, John DT, Krotoski WA, eds. Markell and Voge's Medical Parasitology. 8th edn. Philadelphia; Pennsylvania; W.B. Saunder's Company; 1999; 24-89.
11. Lindsay DS, Dubey JP, Toiviokinnucan MA, Michiels JF, Blagburn BL. Examination of extraintestinal tissue cysts of Isospora belli . J Parasitol 1997; 83:620-625.
12. Benator DA, French AL, Beaudet LM, Levy CS, Orenstein JM. Isospora belli infection associated with acalculous cholecyctitis in a patient with AIDS . Ann Intern Med 1994; 121 : 663-664(Malik Sonia, Samantaray J)