Isospora belli Infection with Chronic Diarrhea in an Alcoholic Patient

Intestinal Parasitic Infections in 2023

Intestinal parasites include intestinal protozoa and intestinal helminths. Intestinal parasitic infections (IPIs) pose a global health problem affecting over one billion people worldwide. Although these infections are predominantly seen in the developing world, they are frequently seen in the developed countries, particularly in immunocompromised patients. Patients' clinical presentations generally include diarrhea, dysentery, abdominal pain, nausea, vomiting, nutritional deficiency, iron deficiency anemia, anal and perianal itching, and rarely intestinal obstruction. The intestinal parasites have similarities in their mode of transmission and life cycle. The stool test is the primary way of diagnosing IPIs. Treatment is given with various anti-parasitic agents. However, appropriate preventive measures are essential for successfully controlling the IPIs.

Chronic cystoisosporiasis in an immunocompetent adult: A case report

RATIONALE

Cystoisosporiasis is an intestinal infectious disease caused by a coccidian protozoa, Cystoisospora belli (C. belli). It can cause prolonged and refractory diarrhea most commonly in immunocompromised patients, while immunocompetent individuals usually exhibit no symptoms or self-limited diarrhea.

PATIENT CONCERNS

We herein report a case of chronic cystoisosporiasis in an immunocompetent patient. A 62-year-old man, who had been first diagnosed with cystoisosporiasis 15 years ago and had been treated with oral administration of trimethoprim-sulfamethoxazole (TMP-SMX), complained of persistent watery diarrhea. He was negative for anti-human immunodeficiency virus antibody and anti-human T-cell leukemia virus type 1 (HTLV-1) antibody.

DIAGNOSIS

Biopsy specimens from the duodenum revealed oocysts in the atrophic absorptive epithelium and protozoa were detected through stool examination, indicating the recurrence of cystoisosporiasis. Capsule endoscopy showed diffuse atrophic mucosa with white villi in the entire small intestine. We diagnosed him with chronic cystoisosporiasis that occurred in an immunocompetent adult.

INTERVENTIONS

Since oral administration of TMP-SMX and ciprofloxacin were ineffective, the intravenous administration of TMP-SMX was initiated.

OUTCOMES

Intravenous TMP-SMX exhibited a significant improvement.

LESSONS

This case indicates that even immunocompetent individuals may develop recurrent and refractory cystoisosporiasis. Furthermore, intravenous treatment of antibiotic agents should be considered when the impaired absorptive ability from the small intestine is suspected.

Cystoisospora belli infections in humans: the past 100 years

Cystoisospora belli is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed, but mainly found in tropical and subtropical areas. Many cases of C. belli infections have been reported in patients with HIV, and in patients undergoing immunosuppressive therapy for organ transplants or those treated for tumours worldwide. Unsporulated or partially sporulated oocysts of C. belli are excreted in feces. When sporulated oocysts in contaminated water or food are ingested, asexual and sexual stages of C. belli are confined to the epithelium of intestines, bile ducts and gallbladder. Monozoic tissue cysts are present in extra-intestinal organs (lamina propria of the small and large intestine, lymph nodes, spleen, and liver) of immunosuppressed humans. However, a paratenic host has not been demonstrated. Cystoisospora belli infections can be persistent, lasting for months, and relapses are common; the mechanism of relapse is unknown. Recently, the endogenous stages of C. belli were re-examined and attention was drawn to cases of misidentification of non-protozoal structures in the gallbladder of patients as C. belli. Here, we review all aspects of the biology of C. belli, including morphology, endogenous stages, prevalence, epidemiology, symptoms, diagnosis and control.

A road less travelled: Clinical comparison of HIV seropositive and seronegative patients with cystoisosporiasis - An 11-year experience from a tertiary care centre in Northern India

Background

Cystoisospora is a well-known opportunistic enteric parasite among human immunodeficiency virus (HIV) seropositive patients but there is a paucity of data among HIV negative patients. This study investigated Cystosporiasis on both HIV positive and negative patients, with or without diarrhea, presenting to a tertiary care and super specialty center of northern India.

Methodology

Oocysts of Cystoisospora were detected on light microscopy, by modified Kinyoun staining of stool specimens, over an 11-year study period.

Results

Of the 10,233 stool specimens evaluated, Cystoisospora was detected in 64 patients, 37 (57.81%) of whom were HIV positive. Year-wise analysis showed an overall declining trend of cystoisosporiasis. Maximum cases were detected in May and June in HIV positive patients and February and September among HIV negative patients. Among HIV positive patients, the mean CD4 count was 152.04 ± 81.12cells/μL, mean absolute eosinophil count (AEC) was 229.16 ± 175.62 cells/μL and 12.5% patients had mild eosinophilia. Tuberculosis was the most common co-morbidity. Dual infections of Cystoisospora with Cryptosporidium and Giardia were also seen. Among HIV negative patients, eight had primary autoimmune disorders, seven were solid organ transplant recipients and the rest had chronic bowel diseases. The mean AEC was 485.47 ± 414.88 cells/μL, with 14.81% patients showing mild and 11.11% showing marked eosinophilia. Dual infection with Giardia was seen. Recurrent cystoisosporiasis was noted, despite cotrimoxazole treatment in a single case.

Conclusion

The epidemiology of cystoisosporiasis differs between HIV seropositive and seronegative patients in terms of year-wise and month-wise trends, co-infections and most importantly, AECs.

Endogenous development of Cystoisospora belli in intestinal and biliary epithelium of humans

Cystoisospora(Isospora)belliis a coccidian parasite of humans. It can cause serious digestive disorders involving infection of intestines, biliary tract and gallbladder, especially in those with depressed immunity. It has a direct fecal–oral transmission cycle. After ingestion of sporulated oocysts, the parasite multiplies asexually and sexually within host epithelial cells, resulting in unsporulated oocysts that are excreted in feces. The details of asexual and sexual stages are not known and certain inclusions in epithelial cells in biopsy samples have been erroneously identified recently asC. belli. Here, we provide details of developmental stages ofC. belliin two patients, in duodenal biopsy of one and biliary epithelium of the other. Immature and mature asexual stages (schizonts/meronts) were seen in epithelial cells. The merozoites were seen singly, in pairs and in groups in single parasitophorous vacuole (pv) in host cytoplasm. Immature and mature meronts were seen together in the same pv; up to eight nuclei were seen in meronts that retained elongated crescent shape; round multinucleated schizonts, seen in other coccidians, were not found. Meronts were up to 25µm long and contained up to ten merozoites that were 8–11µm long. The merozoites and meronts contained PAS-positive granules. Microgamonts (male) contained up to 30 nuclei that were arranged at the periphery and had condensed chromatin; 1–3 PAS-positive, eosinophilic, residual bodies were left when microgametes were formed. The microgametes were 4µm long and PAS-negative. All stages of macrogamonts, including oocysts were PAS-positive. The detailed description of the life cycle stages ofC. bellireported here should facilitate in histopathologic diagnosis of this parasite.

Unexpectedly High Prevalence of Cystoisospora belli Infection in Acalculous Gallbladders of Immunocompetent Patients

Objectives

Indications for cholecystectomy have changed dramatically over the past three decades. Cystoisospora belli has been reported in cholecystectomy specimens of immunocompetent patients. The present study was designed to determine the prevalence and clinical association of C belli in the gallbladder.

Methods

The study included retrospective review of cholecystectomy specimens (n = 401) removed for various indications, and a prospective cohort of cholecystectomy specimens (n = 22) entirely submitted for histologic evaluation. Correlations of presence of C belli with age, sex, clinical indication, and abnormalities of preoperative laboratory values were assessed by Fisher exact test.

Results

C belli was identified in 39/401 (9.7%) of the retrospective cohort, and 6/22 (27.3%) of the entirely submitted specimens. The presence of C belli showed no correlation with age, sex, clinical indication, or laboratory abnormalities.

Conclusions

C belli resides in a latent state in the gallbladder and may be best considered a commensal organism.

Uncommon and fatal case of cystoisosporiasis in a non HIV-immunosuppressed patient from a non-endemic country

Cystoisospora belli (previously known as Isospora belli) is a tropical coccidian parasite sometimes leading to severe diarrhea in immunocompromised patients. Here we describe a fatal case of cystoisosporiasis in a non HIV-immunocompromised 71-year-old female with no recent travel history. Infection was either latent or potentially caused by the consumption of contaminated imported food from Asia. Diagnosis was made by microscopical detection of numerous C. belli oocysts in stools without specific staining. Treatment with TMP-SMZ slightly improved diarrhea within 3days, but dehydration subsequently led to acute decompensated heart failure and a fatal evolution. This report illustrates the possibility of severe cystoisosporiasis in non HIV-immunocompromised patients in a non-endemic country and highlights the risk of transmission through imported contaminated food consumption.

Intestinal coccidian parasites as an underestimated cause of travellers' diarrhoea in Polish immunocompetent patients

Intestinal coccidian parasites are intracellular protozoa most frequently transmitted during food-borne and water-borne infections. This group of parasites is responsible for acute diarrhoeal illnesses especially among immunocompromised patients. However, they are more frequently detected in immunocompetent individuals including travellers, and they should also be considered as important etiologic factors of travellers' diarrhoea. We examined 221 immunocompetent patients hospitalized due to acute or chronic diarrhoea and other gastrointestinal symptoms after returning from international journeys to hot climates. A basic microscopical examination and acid - fast staining of stool samples was performed. Each patient was also a part of the epidemiological investigation to define potential risk factors of tropical gastrointestinal infections. Intestinal coccidiosis was confirmed in 12 out of 221 successively hospitalized patients (5.4%). The most common coccidian parasite was Cryptosporidium spp., detected in nine Polish travellers (4.1%). Cyclospora spp. was diagnosed in three cases (1.4%), including two mixed infections with Cryptosporidium spp., and Cystoisospora spp. in two other cases (0.9%). The study has revealed that intestinal coccidian parasites are a significant threat to immunocompetent travellers and should be always considered in the differential diagnosis of gastrointestinal disorders. Therefore, it is necessary to perform specialized diagnostic methods for the detection of Cryptosporidium spp., Cystoisospora spp., and Cyclospora spp. oocysts in reference parasitology laboratories. Clinical observations demonstrated simultaneously an insufficient level of knowledge in Polish tourists concerning the main risk factors of intestinal parasitic diseases during international travels, particularly to developing countries with lower economic and sanitary conditions.

Chronic Cystoisospora belli infection in an immunocompetent Myanmar refugee - microscopy is not sensitive enough

BACKGROUND

Cystoisosporiasis is an opportunistic infection seen more commonly in patients with acquired immunodeficiency syndrome. Although uncommon, Cystoisospora infection can occur in immunocompetent individuals but tend to be benign and self-limiting. Chronic infection however, has been described but diagnosis can often be challenging and requires a high clinical index of suspicion.

CASE PRESENTATION

We present a case of delayed diagnosis of Cystoisospora belli (C. belli) in an immunocompetent 28-year-old refugee from Myanmar. She had a history of chronic diarrhea where exhaustive investigations over many years failed to reveal a diagnosis. Cystoisospora belli cysts were finally detected in stool 4 years after investigation commenced, and PCR testing on stored colon biopsies amplified a molecular product with 99 % sequence homology to C. belli. The patient improved promptly with trimethoprim-sulfamethoxazole treatment.

CONCLUSION

In the appropriate clinical context we suggest molecular testing for C. belli or an empirical therapeutic trial.

Eosinophils in Gastrointestinal Disorders: Eosinophilic Gastrointestinal Diseases, Celiac Disease, Inflammatory Bowel Diseases, and Parasitic Infections

The gastrointestinal (GI) tract provides an intriguing organ for considering the eosinophil's role in health and disease. The normal GI tract, except for the esophagus, is populated by eosinophils that are present throughout the mucosa, raising the possibility that eosinophils participate in innate mechanisms of defense. However, data from clinical studies associates increased numbers of eosinophils with inflammatory GI diseases, prompting concerns that eosinophils may have a deleterious effect on the gut. We present clinical features of 4 disease processes that have been associated with eosinophilia and suggest areas requiring investigation as to their clinical significance and scientific relevance.