Infection with Cryptosporidium hominis and reinfection with Cryptosporidium parvum in a transplanted ileum

Cryptosporidium sp. infection in solid organ transplant recipients: A systematic review and meta-analysis

(1) Background: Organ transplant recipients (OTRs) are vulnerable groups at risk of parasitic infections. This systematic review and meta-analysis aimed to evaluate the overall prevalence of Cryptosporidium sp. in OTRs and shed light on this potentially serious complication of organ transplantation. (2) Methods: We systematically searched studies on Cryptosporidium sp. infections in OTRs in four databases (Academia, PubMed, Scopus, and Science Direct). Random effects models were used to calculate pooled prevalence estimates with 95% confidence intervals (CIs). Sub-group and meta-regression analyses were conducted. A quality assessment of the included studies was also performed. (3) Results: Among 876 articles retrieved, 21 were included, accounting for 2,642 OTRs. Twenty studies were cross-sectional in design, of which seven reported data on a comparison group, and one was a retrospective cohort. The pooled prevalence of Cryptosporidium sp. in OTRs was 15% (95% CI: 7.4-24.6). Subgroup analysis revealed that the prevalence of Cryptosporidium sp. infection was higher in adults, symptomatics and developing countries and in studies using only non-molecular methods. However, substantial heterogeneity was reported. Low to moderate heterogeneity was observed in subgroups reporting lower prevalence Cryptosporidium sp. including children (5.8; 95% CI: 2.8-9.6), studies conducted in developed countries (5.8; 95% CI: 3.0-9.4) and studies using both molecular and non-molecular diagnostics (11.4; 95% CI: 6.4-17.4). The majority of the listed research reported low-medium quality scores. (4) Conclusion: Cryptosporidium sp. infection is a significant complication in OTRs with underreported prevalence. Preventive strategies to reduce the burden should include Cryptosporidium sp. routine screening for OTRs, particularly post-transplantation in patients with diarrhea. Additional well-designed research studies are required to determine the extent of the Cryptosporidium sp. burden in OTRs.

Infectious Gastroenteritis in Transplant Patients

Infectious gastroenteritis is common after transplantation and can lead to increased morbidity and mortality. A wide range of organisms can lead to gastroenteritis in this patient population. Clostridioides difficile, cytomegalovirus, and norovirus are the most common pathogens. Newer diagnostic methods, especially multiplex polymerase chain reaction, have increased the diagnostic yield of infectious etiologies. In this review, we describe the epidemiology and risk factors for common infectious pathogens leading to gastroenteritis.

Prevalence of Intestinal Parasitic Infection in Cancer, Organ Transplant and Primary Immunodeficiency Patients in Tehran, Iran

Background:

Intestinal parasitic infection in immunodeficient patients especially those with impaired cellular immunity, like neoplasia, renal or heart transplant needs careful consideration. The objective of this study is to evaluate the prevalence of intestinal parasites in different group of patients including cancer patients; organ transplants recipients, and primary immunodeficiency patients.

Methods:

Stool samples from 190 patients including 80 patients with Primary Immunodeficiency, 85 cancer patients and 25 organ transplant recipients were collected; a direct examination with Phosphate buffered saline (PBS) and formalin ether concentration was performed. The DNA was extracted from parasitologically confirmed patients and nested PCR and sequencing was performed and new obtained sequences of Cryptosporidium parvum and Enterocytozoon bieneusi were compared with deposited ones.

Results:

In general, the prevalence of parasites was 26/80 (32.5%) in primary immunodeficiency, 22/85(25.9%) in cancer group, and 7/25 (28%) in organ transplant. The prevalence of intestinal parasitic infections in primary immunodeficiency patients were Blastocystis hominis 13 (16.2%), Giardia lamblia 10 (12.5%), Cryptosporidium 1(1.2%), Chilomastix mesnilii 1 (1.2%), Dientamoeba fragilis 1(1.2%). Of 25 organ transplants, 6 (24%) Cryptosporidium sp were found, all of which were confirmed as Cryptosporidium parvum and one case of Microspora in a heart transplant recipient was confirmed as Enterocytozoon bieneusi by PCR sequencing. The predominant intestinal parasitic infection in cancer patients was 19 (22.3%) Blastocystis hominis followed by two (2.3%) Giardia lamblia and one Dientamoeba fragilis 1 (1.1%).

Conclusion:

The high rate of infection with Blastocystis hominis was found in cancer patients especially colorectal cancer patients, so careful consideration should be given by physicians. Cryptosporidium sp was found to be the major cause of parasitic intestinal infection in patients with organ transplant compared to primary immunodeficiency patients; so transplant recipients undergoing immunosuppressive therapy should be considered as a risk group for acquiring microsporidiosis and Cryptosporidium infection.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.

The therapeutic efficacy of azithromycin and nitazoxanide in the acute pig model of Cryptosporidium hominis

Recent reports highlighting the global significance of cryptosporidiosis among children, have renewed efforts to develop control measures. We have optimized the gnotobiotic piglet model of acute diarrhea to evaluate azithromycin (AZR), nitazoxanide (NTZ), or treatment with both against Cryptosporidium hominis, the species responsible for most human cases. Piglets, animals reproducibly clinically susceptible to C. hominis, when inoculated with 10⁶ oocysts, developed acute diarrhea with oocyst excretion in feces within 3 days. Ten day-treatment with recommended doses for children, commencing at onset of diarrhea, showed that treatment with AZR or NTZ relieved symptoms early in the treatment compared with untreated animals. Piglets treated with AZR exhibited no reduction of oocyst excretion whereas treatment with NTZ significantly reduced oocyst shedding early, increasing however after 5 days. While treatment with AZR+NTZ led to considerable symptomatic improvement, it had a modest effect on reducing mucosal injury, and did not completely eliminate oocyst excretion. Doubling the dose of AZR and/or NTZ did not improve the clinical outcome, confirming clinical observations that NTZ is only partially effective in reducing duration of diarrhea in children. This investigation confirms the gnotobiotic piglet as a useful tool for drug evaluation for the treatment of cryptosporidiosis in children.

Cryptosporidium infection in solid organ transplantation

Diarrhea is a common complication in solid organ transplant (SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.

Diarrhea in solid-organ transplant recipients: a review of the evidence

OBJECTIVE

To provide a comprehensive review of the literature as it relates to diarrhea in solid organ transplant (SOT) recipients. In this article, we review the epidemiology, pathogenesis, clinical manifestations, diagnosis and management of diarrhea in SOT recipients and discuss recent advances and challenges.

METHODS

Two investigators conducted independent literature searches using PubMed, Web of Science, and Scopus until January 1st, 2013. All databases were searched using a combination of the terms diarrhea, solid organ transplant, SOT, transplant associated diarrhea, and transplant recipients. Articles that discussed diarrhea in SOT recipients were reviewed and relevant cross-references also read and evaluated for inclusion. Selection bias could be a possible limitation of the approach used in selecting or finding articles for this article.

FINDINGS

Post-transplant diarrhea is a common and distressing occurrence in patients, which can have significant deleterious effects on the clinical course and well-being of the organ recipient. A majority of cases are due to infectious and drug-related etiologies. However, various other etiologies including inflammatory bowel disease must be considered in the differential diagnosis. A step-wise, informed approach to post-transplant diarrhea will help the clinician achieve the best diagnostic yield. The use of diagnostic endoscopy should be preceded by exclusion of an infectious or drug-related cause of diarrhea. Empiric management with antidiarrheal agents, probiotics, and lactose-free diets may have a role in managing patients for whom no cause can be determined even after an extensive investigation.

CONCLUSIONS

Physicians should be familiar with the common etiologies that result in post-transplant diarrhea. A directed approach to diagnosis and treatment will not only help to resolve the diarrhea but also prevent potentially life-threatening consequences including loss of the graft as well. Prospective studies are required to determine the etiology of post-transplant diarrhea in different clinical and geographic settings.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Cryptosporidium enteritis in solid organ transplant recipients: multicenter retrospective evaluation of 10 cases reveals an association with elevated tacrolimus concentrations

BACKGROUND

Cryptosporidial enteritis, a diarrheal infection of the small intestine caused by the apicomplexan protozoa Cryptosporidium, is infrequently recognized in transplant recipients from developed countries.

METHODS

A retrospective review of all cases of cryptosporidiosis in solid organ transplant (SOT) recipients at 2 centers from January 2001 to October 2010 was performed and compared with transplant recipients with community-onset Clostridium difficile infection (CDI). A literature search was performed with regard to reported cases of cryptosporidiosis in SOT recipients.

RESULTS

Eight renal, 1 liver, and 1 lung transplant recipient were diagnosed with cryptosporidiosis at median 46.0 months (interquartile range [IQR] 25.2-62.8) following SOT. Symptoms existed for a median 14 days (IQR 10.5-14.8) before diagnosis. For the 9 patients receiving tacrolimus (TAC), mean TAC levels increased from 6.3 ± 1.1 to 21.3 ± 9.2 ng/mL (P = 0.0007) and median serum creatinine increased temporarily from 1.3 (IQR 1.1-1.7) to 2.4 (IQR 2.0-4.6) mg/dL (P = 0.008). By comparison, 8 SOT recipients (6 kidney, 2 liver) hospitalized with community-onset CDI had a mean TAC level of 10.8 ± 2.8 ng/dL during disease compared with 9.2 ± 2.3 ng/mL at baseline (P = 0.07) and had no change in median creatinine. All patients recovered from Cryptosporidium enteritis after receiving various chemotherapeutic regimens.

CONCLUSIONS

Cryptosporidiosis should be recognized as an important cause of diarrhea after SOT and is associated with elevated TAC levels and acute kidney injury. Increased TAC levels may reflect altered drug metabolism in the small intestine.

Severe cryptosporidiosis in a seven-year-old renal transplant recipient: case report and review of the literature

Cryptosporidium is an intracellular protozoa that can cause gastroenteritis in humans. In immunocompromised hosts, infection can be severe, leading to life-threatening persistent diarrhea. There is limited experience in treating this infection in solid organ transplants. Although newer drugs active against Cryptosporidium exist, they are only licensed in the USA for treatment of immunocompetent hosts. Here we describe a seven-year-old renal transplant recipient with severe cryptosporidiosis. He had a protracted course of diarrhea of up to 2 L/day. He was successfully managed with combination antimicrobial therapy including nitazoxanide, paromomycin, and azithromycin. In conjunction with this regimen, he had a reduction in immunosuppression and complete bowel rest. His stool pattern normalized in four weeks and he has had no recurrence after six months of follow up.

Parasitic infections in transplant recipients

Parasitic infections are important complications of organ transplantation that are often overlooked in the differential diagnosis of post-transplantation pyrexial illness. Although their frequency is unknown, they seem to be much less prevalent than bacterial and viral infections. Only 5% of human pathogenic parasites have been reported to cause significant illness in transplant recipients. Infection can occur via transmission with the graft or blood transfusion, or be acquired de novo from the environment. Recrudescence of dormant infection can lead to active disease. Post-transplantation parasitic disorders tend to cluster into two clinical profiles. First, an acute systemic illness with anemia, constitutional manifestations and variable stigmata of organ involvement; acute graft dysfunction can lead to confusion and acute rejection. Protozoa including malarial Plasmodium, Leishmania, Trypanosoma and Toxoplasma are associated with this profile. The second typical manifestation encompasses a few localized syndromes, usually associated with the lower gastrointestinal tract, caused by either protozoa (Cryptosporidium and microsporidia) or nematodes (Strongyloides and Ascaris). Dissemination of localized infections can lead to life-threatening systemic manifestations. A high index of suspicion is essential, as diagnosis requires special sampling techniques and laboratory procedures. Definitive diagnosis is usually achieved by detecting the parasite in the patient's tissues or body fluids by histological examination or culture, or by polymerase chain reaction amplification of the parasite-specific antigen sequence. Antibody detection using serological techniques is also possible in a few parasitic infections. Certain lesions have characteristic radiological appearances, hence the value of imaging, particularly in the cerebral syndromes. Treatment is usually straightforward (broad spectrum or specific drugs), yet some species are drug resistant.

Advances in the epidemiology, diagnosis and treatment of cryptosporidiosis

Cryptosporidiosis, the disease caused by protozoa of the genus Cryptosporidium, represents a major public health problem in both developing and developed countries. The infection can be severe and life threatening among immunocompromised individuals, particularly in AIDS patients and in those with primary immunodeficiency diseases. This review examines the essential aspects of the epidemiology of the infection, highlighting the role of animals, water and food. A critical evaluation of the diagnostic tools used in clinical settings is also provided. Lastly, the review examines the chemotherapeutic options available to treat the infection, and underlines the need to design and test new drugs. The review concludes with a five-year outlook on some aspects of interest for future research on this pathogen.

Gastrointestinal parasites in the immunocompromised

PURPOSE OF REVIEW

Parasites and other infections have many effects on the gastrointestinal tract of individuals who are immunocompromised. Few reviews focus on parasitic infections, which are covered here.

RECENT FINDINGS

The review first examines recent advances in our understanding of the taxonomy, diagnosis and treatment of pathogens such as cryptosporidia, cyclospora, isospora and microsporidia, which are recognized causes of diarrhoea in the immunocompromised, and discusses possible links between amoebiasis and HIV. The complex interactions of both intact and abnormal immune systems with helminth infections such as hookworm and strongyloidiasis, and with trematode infections such as schistosomiasis, are receiving increasing attention. These are discussed, together with the novel concept of using live helminths to treat inflammatory bowel disease.

SUMMARY

Parasitic infections remain a significant problem for immunocompromised individuals in resource-poor settings, and further work is needed to develop accessible diagnostic tests and to improve our understanding and management of their pathogenic effects. New concepts about the interactions of helminths with host immunity suggest the need for collection of further epidemiological and clinical data to unravel the complexities of such immunological interactions.