Case Report: Molecular Diagnosis of Cystoisospora belli in a Severely Immunocompromised Patient with HIV and Kaposi Sarcoma.

Diarrhea in an immunocompromised patient has a broad infectious differential. Diagnosis is difficult despite advances in diagnostic modalities. We report a case of a 45-year-old Nigerian woman who immigrated to the United States 2 years ago. She presented to the hospital with gastrointestinal bleeding, newly diagnosed HIV, and disseminated Kaposi sarcoma. During hospitalization, the patient had an onset of watery diarrhea and high eosinophilia. Subsequent stool analysis using multi-parallel real-time quantitative polymerase chain reaction for 13 parasites was positive for Cystoisospora belli. The patient was treated with trimethoprim-sulfamethoxazole, but had relapsed disease when her antibiotics were stopped prematurely. After restarting trimethoprim-sulfamethoxazole, her diarrhea and eosinophilia improved, and she had undetectable Cystoisospora belli DNA on repeat stool quantitative polymerase chain reaction. This case highlights the importance of a thorough workup for diarrhea, including parasites, especially for immunocompromised patients. Antibiotic prophylaxis is recommended in patients with Cystoisospora belli and HIV/AIDS.

Epithelial Inclusions in Gallbladder Specimens Mimic Parasite Infection: Histologic and Molecular Examination of Reported Cystoisospora belli Infection in Gallbladders of Immunocompetent Patients.

Recent publications have described epithelial cytoplasmic vacuoles and inclusions incidentally noted within gallbladder epithelium and concluded that they represent coccidian parasite infection, in particular, Cystoisospora belli. We identified 8 gallbladder specimens from our institution in the past 3 years in which this diagnosis was suggested or in which similar epithelial alterations were prominent. Molecular analysis was performed on the 8 gallbladder specimens and on 3 positive control specimens: small bowel biopsies from acquired immunodeficiency syndrome patients with diarrhea. Polymerase chain reaction using primers designed to amplify an internal transcribed spacer (ITS2) in the C. belli ribosomal gene cluster was performed on the DNA samples. All 8 gallbladder specimens were negative for amplification, while a product consistent with C. belli was amplified from all 3 positive controls. Histologically, the gallbladder cytoplasmic inclusions stained diffusely positive for Grocott-Gomori's methenamine silver and Periodic acid-Schiff with diastase. In contrast, sections from a positive control small bowel biopsy demonstrated organisms that were negative for Grocott-Gomori's methenamine silver and showed a distinct capsular and punctate internal staining on Periodic acid-Schiff with diastase in various parasite forms. Together, the lack of molecular evidence of C. belli and the distinct morphologic and special staining patterns in these gallbladders compared with positive control small bowel suggest that these epithelial changes do not represent true C. belli infection. Our results suggest that gallbladders of immunocompetent patients may occasionally show epithelial changes that can morphologically mimic C. belli infection. Pathologists should be aware of this histologic variant to minimize unnecessary treatment, testing, and patient anxiety.

Infestación por Cryptosporidium Spp e Isospora Belli en preescolar inmunocompetente: a propósito de un caso / Infestation by Crytosporidium Spp and Isospora belli in immunocompetent preschool: a report of a case

El Cryptosporidium spp e Isospora belli son parásitos emergentes, que representan la cuarta causa de diarrea a nivel mundial, principalmente en niños y en pacientes inmunocomprometidos. Producen diarrea aguda o crónica dependiendo de la edad del paciente, estado nutricional e inmunológico asociado a factores sanitarios desfavorables. El diagnostico se realiza por visualización directa en heces con tinción de Zelh Neelsen modificado o Kinyou y biopsia intestinal con presencia de protozoos en las criptas y atrofia vellositaria de acuerdo al grado de infestación. Se reporta el caso de preescolar de 2 años de edad, eutrófico e inmunocompetente, perteneciente a estrato social bajo; con episodios de diarreas acuosas autolimitadas, dolor y distensión abdominal frecuentes. La biopsia intestinal revelo atrofia vellositaria e infestación simultanea por Cryptosporidium spp e Isospora belli corroborado por Tinción de Kinyou en heces; se descarto además Alergia Alimentaria, Enfermedad Celiaca e Inmunodeficiencias. El propósito de este caso clínico es alertar sobre la necesidad de incluir dentro del protocolo de estudio de diarrea crónica, la búsqueda de protozoarios formadores de esporas, mediante tinción especial en heces; un método no invasivo y sencillo, no solicitado en forma rutinaria.

Cryptosporidium spp and Isospora belli parasites are emerging that represent the fourth leading cause of diarrhea worldwide, mainly in children and in immunocompromised patients. Acute or chronic diarrhea occur depending on the patient's age, nutritional status and immunological factors associated with adverse health. The diagnosis is made by direct visualization in feces Neelsen stain Zelh Kinyou modified or intestinal biopsy and the presence of protozoa in the crypts and villous atrophy according to the degree of infestation. We report the case of preschool age 2, eutrophic immunocompetent, belonging to low socioeconomic levels, with self-limiting episodes of acute watery diarrhea, frequent abdominal pain and bloating. The intestinal biopsy revealed villous atrophy and simultaneous infestation by Cryptosporidium spp and Isospora belli Kinyou confirmed by staining in feces, while discarding also Food Allergy, Celiac disease and immunodeficiencies. The purpose of this case to alert about the need to include in the study protocol of chronic diarrhea, the search for spore-forming protozoa by special staining in feces, a noninvasive and simple method, not routinely requested.

Cystoisospora canis Nemeséri, 1959 (syn. Isospora canis), infections in dogs: clinical signs, pathogenesis, and reproducible clinical disease in beagle dogs fed oocysts.

Canine intestinal coccidiosis is a cause of diarrhea in young dogs and dogs that are immunocompromised. Reports in the literature indicate that experimental reproduction of clinical coccidiosis with Cystoisospora canis (syn. Isospora canis) is difficult, and few studies have been done with C. canis. Experimental oral infections were attempted in 22, 6- to 8-wk-old female beagles with 5 x 10(4) (n = 2) or 1 x 10(5) (n = 20) sporulated C. canis oocysts. Diarrhea was observed in all inoculated dogs. Diarrhea began 2-3 days before oocyst excretion. Five of the 22 dogs were given an anticoccidial (sulfadimethoxine) because of their clinical signs. The mean prepatent period was 9.8 days (range, 9-11 days, n = 22 dogs), and the patent period was 8.9 days (range, 7-18 days, n = 20 dogs). Two dogs exhibiting clinical coccidiosis were examined at necropsy 10 days after infection. Developmental stages of C. canis were present in cells in the lamina propria throughout the entire small intestine in both dogs. Microscopic lesions observed in both of these dogs were villous atrophy, dilation of lacteals, and hyperplasia of lymph nodes in Peyer's patches. Results of bacterial and viral examinations of these 2 dogs were negative, indicating that intestinal coccidiosis was the cause of the diarrhea. Our study indicates that C. canis can be a primary cause of diarrhea in young dogs.