Intestinal parasites including Cryptosporidium, Cyclospora, Giardia, and Microsporidia, Entamoeba histolytica, Strongyloides, Schistosomiasis, and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre- and post-transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid-organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post-transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor-derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid-organ transplant recipients are unmet needs.

Confirmed microsporidial graft infection in a HIV-negative renal transplant recipient: A case report and review of the literature.

Microsporidia are intracellular organisms most commonly known to cause opportunistic infection in patients with human immunodeficiency virus (HIV). There have been several case reports of infection in solid organ and bone marrow transplant recipients. Here, we report a case of a non-HIV-infected renal transplant patient with microsporidiosis of the renal tract associated with acute graft dysfunction. We also review the literature of 12 previously reported cases of microsporidiosis in patients with renal transplants who had described graft involvement. We review the pattern of illness as well as the common renal biopsy features when microsporidial infection is associated with renal graft infection.

The first study on opportunistic intestinal microsporidiosis in IBD patients receiving immunosuppressive medications in Iran.

Microsporida are known as opportunistic unicellular organisms and have recently been reclassified as fungi that have been frequently reported from patients with congenital and acquired immunity failure disorders, worldwide. However, use of immunosuppressive medications in inflammatory bowel disease (IBD) patients significantly decreases overall immunity, and increases their susceptibility to opportunistic infections. Totally, 71 stool samples were collected from IBD patients consisted of 69 ulcerative colitis (UC) patients and two Crohn's disease (CD) patients. All patients had taken immunosuppressive and/or immunomodulator drugs for at least 3 weeks. DNA was extracted from all stool samples and Nested PCR was performed using genus-specific primers based on small subunit ribosomal RNA (SSU rRNA) gene. Fisher's Exact Test was applied to evaluate statistical association between microsporidia infection and sex, age and types of IBD. Mean of age ± s.d., women and men percentage of the attended patients were 36·17 ± 11·93, 60·6%, and 39·4%, respectively. A 440-bp fragment of SSU rRNA gene attributed to Enterocytozoon bieneusi was amplified from 12·7% of IBD patients. No Encephalitozoon DNA was detected in the samples. No microsporidia-positive sample was found in CD patients. Fisher's Exact Test showed that there was no statistically significant correlation between intestinal microsporidiosis and age, sex, and IBD types with P values: 0·389, 1·00, and 1·00, respectively. This study has shown IBD patients undergoing immunosuppressive/immunomodulators medications, which may be susceptible to intestinal microsporida infection. E. bieneusi is the commonest intestinal microsporidan reported from IBD patients.

Microsporidiosis in pediatric renal transplant patients in Cape Town, South Africa: two case reports.

Microsporidia are an emerging group of pathogens associated with life-threatening opportunistic infections in immunocompromised hosts, particularly human immunodeficiency virus (HIV)-infected individuals. There have, however, been recent reports of infection in adult solid organ transplant recipients. We report two cases in children, to our knowledge the first in the paediatric literature. Two 13-yr-old, HIV-seronegative females received deceased donor renal transplants from the same donor. Both patients suffered acute cell-mediated rejection and CMV infection reactivation, managed with intensified immunosuppression and ganciclovir. Pyrexia of unknown origin and intermittent diarrhea in both prompted extensive investigations. In both patients, numerous spores of a microsporidial species were demonstrated in renal tissue on biopsy and in the urine, using modified trichrome and quick-hot Gram-chromotrope staining. Electron microscopy and PCR confirmed Encephalitozoon cuniculi infections. Both patients were successfully treated with 400 mg twice daily of albendazole, with sustained clinical improvement. We recommend that microsporidiosis be considered in the differential diagnosis of pyrexia of unknown origin in severely immunocompromised pediatric solid organ transplant recipients, particularly when associated with diarrhea.

Microsporidia MB is found predominantly associated with Anopheles gambiae s.s and Anopheles coluzzii in Ghana.

A vertically transmitted microsporidian, Microsporidia MB, with the ability to disrupt Plasmodium development was reported in Anopheles arabiensis from Kenya, East Africa. To demonstrate its range of incidence, archived DNA samples from 7575 Anopheles mosquitoes collected from Ghana were screened. MB prevalence was observed at 1.8%. An. gambiae s.s constituted 87% of positive mosquitoes while the remaining were from An. coluzzii. Both sibling species had similar positivity rates (24% and 19%; p = 0.42) despite the significantly higher number of An. gambiae s.s analysed (An. gambiae s.s = 487; An. coluzzii = 94; p = 0.0005). The microsporidian was also more prevalent in emerged adults from field-collected larvae than field-caught adults (p < 0.0001) suggestive of an efficient vertical transmission and/or horizontal transfer among larvae. This is the first report of Microsporidia MB in Anopheles mosquitoes in West Africa. It indicates possible widespread among malaria vector species and warrants investigations into the symbiont's diversity across sub-Saharan Africa.

Emerging and reemerging infectious diseases of nonhuman primates in the laboratory setting.

Despite numerous advances in the diagnosis and control of infectious diseases of nonhuman primates in the laboratory setting, a number of infectious agents continue to plague colonies. Some, such as measles virus and Mycobacterium tuberculosis, cause sporadic outbreaks despite well-established biosecurity protocols, whereas others, such as retroperitoneal fibromatosis-associated herpesvirus, have only recently been discovered, often as a result of immunosuppressive experimental manipulation. Owing to the unique social housing requirements of nonhuman primates, importation of foreign-bred animals, and lack of antemortem diagnostic assays for many new diseases, elimination of these agents is often difficult or impractical. Recognition of these diseases is therefore essential because of their confounding effects on experimental data, impact on colony health, and potential for zoonotic transmission. This review summarizes the relevant pathology and pathogenesis of emerging and reemerging infectious diseases of laboratory nonhuman primates.

Multimethodological Approach to Gastrointestinal Microsporidiosis in HIV-Infected Patients.

PURPOSE: Microsporidiosis is an opportunistic infection that produces chronic diarrhoea and cholangiopathy in patients with AIDS, mainly caused by two species of microsporidia, Enterocytozoon bieneusi and Encephalitozon intestinalis. The aim of this work was to develop an integral system for the diagnosis of microsporidiosis of the intestine and biliary tract in HIV-infected patients, comprising microscopic and molecular techniques. METHODS: The study population comprised 143 adult patients of both sexes with diagnosis of HIV infection, with chronic diarrhoea, and with or without HIV-associated cholangiopathy. Stool studies for microsporidia identification of spores were performed on each patient. A video esofagogastroduodenoscopy with biopsy collection was also carried out for routine histology and semi-thin sections stained with Azure II. Species identification was carried out by transmission electron microscopy and/or polymerase chain reaction for the species E. bieneusi and E. intestinalis. RESULTS: Out of the 143 patients a total of 12.6% (n = 18) were infected with microsporidia. Microsporidia species identified in most cases was E. bieneusi (16/18 cases), followed by E. intestinalis (4/18), all of these last ones in coinfection with E. bieneusi. CONCLUSIONS: Clinical, imaging, microscopic and molecular analyses, when applied in a systematic and integrated approach, allow diagnosis and identification of microsporidia at species level in AIDS patients with chronic diarrhoea, and with or without HIV-associated cholangiopathy.

Spore shedding pattern of Enterocytozoon bieneusi in asymptomatic children.

Stool samples from seven human immunodeficiency virus (HIV)-negative and two HIV-positive children with asymptomatic Enterocytozoon bieneusi infections were daily examined to quantify spore shedding using Gram-chromotrope staining under light microscopy. The spore shedding pattern and intensity in these children was variable. Mean spore concentrations in the stool samples from these children ranged from 2.4 x 10(2) to 1.2 x 10(5) spores per gram. Light microscopy could detect spores in stool specimens for 9-33 days, while PCR was able to detect E. bieneusi in stool specimens for 3-40 days longer. This suggests that light microscopy may not detect low levels of spore shedding. Considering that the asymptomatic group are a potential source of infection, detection methods with a higher sensitivity should be used.

Diarrhoea in HIV-infected patients: no evidence of cytokine-mediated inflammation in jejunal mucosa.

OBJECTIVE: To determine whether a mucosal cytokine-mediated inflammatory response is involved in cryptosporidial or microsporidial diarrhoea, as well as in diarrhoea of unknown origin in HIV-infected patients. DESIGN: Prospective study. METHODS: Jejunal biopsies were obtained from HIV-infected patients with diarrhoea. Controls were HIV-infected and HIV-seronegative patients without diarrhoea. Two biopsies were homogenized immediately and two other biopsies were first cultured for 20 h. Cytokines [tumour necrosis factor (TNF), interleukin (IL)-1 beta, IL-6, IL-8, IL-10], soluble TNF receptors (sTNFR) p55 and p75, and soluble IL-2 receptor (sIL-2R) were assessed in the homogenates and in the supernatants by sandwich enzyme-linked immunosorbent or enzyme-linked binding assays. The cytokine receptors were also measured in serum. RESULTS: Six HIV-infected patients with cryptosporidiosis, six with microsporidiosis, seven with diarrhoea of unknown origin, seven without diarrhoea, and seven HIV-seronegative patients were eligible. Four patients were excluded because of the presence of other pathogens. No cytokines were detected in immediately homogenized jejunal tissue. Following culture, IL-6 and IL-8 levels were higher in HIV-infected patients with diarrhoea of unknown origin than in HIV-seronegative controls without diarrhoea, although this was not statistically significant. No differences in serum or post-culture supernatant sTNFR p55 and p75 levels existed between the HIV-infected patients with or without diarrhoea. sTNFR, IL-1 beta, IL-10 and the sIL-2R were only detected in low amounts or not at all, and were equally distributed among all patient groups. CONCLUSIONS: This study indicates that mucosal cytokine-mediated inflammatory responses do not play an important role in the pathogenesis of different types of diarrhoea in HIV-infected patients. These results do not support the use of immunomodulatory therapy in these patients.

Pulmonary infection with microsporidia after allogeneic bone marrow transplantation.

Microsporidia are obligate, intracellular protozoal parasites that can be pathogenic in immunocompromised individuals. The majority of cases of microsporidiosis have been documented in patients with HIV, and only a few case reports exist of infection in solid organ transplant patients. We report the first case of pulmonary microsporidial infection in an allogeneic bone marrow transplant recipient in the US. The patient was a recipient of a T-cell-depleted graft who succumbed to complications from respiratory failure 63 days post transplant. The diagnosis was made post mortem by electron microscopy and confirmed with PCR. Although rare, microsporidial infection should be considered in the differential diagnosis of unexplained pulmonary infection in bone marrow transplant patients.

Modification of the clinical course of intestinal microsporidiosis in acquired immunodeficiency syndrome patients by immune status and anti-human immunodeficiency virus therapy.

The clinical course of 37 Enterocytozoon bieneusi-infected acquired immunodeficiency syndrome patients with diarrhea was studied. Parasite clearance was seen in 15 patients (40.5%). Clearance of E. bieneusi resulted in a 25-100% reduction in episodes of diarrhea, suggesting that microsporidia are true pathogens. Univariate and multivariate proportional hazards analyses revealed that peripheral blood CD4 cell counts > or = 100/mm3, the use of two or more antiretroviral medications, and use of a protease inhibitor were statistically associated with decreased time to clearance of E. bieneusi. Specific anti-microsporidial therapy (albendazole) was not associated with parasite eradication. Factors related to immunocompetence and human immunodeficiency virus suppression appeared to be important in the clearance of E. bieneusi.

Microsporidial keratoconjunctivitis in a patient without human immunodeficiency virus infection.

PURPOSE: To describe a case of microsporidial keratoconjunctivitis in a patient without human immunodeficiency virus (HIV) infection. METHODS: Case report. An epithelial corneal scraping from a woman with chronic bilateral keratoconjunctivitis was evaluated by Giemsa stain. RESULTS: Giemsa stain of an epithelial corneal scraping disclosed intracellular and extracellular spores characteristic of microsporidia. An HIV enzyme-linked immunosorbent assay (ELISA) test was negative. The signs and symptoms of the bilateral keratoconjunctivitis resolved after treatment with albendazole. CONCLUSION: Microsporidia may cause a chronic epithelial keratoconjunctivitis in the absence of HIV infection.

Microsporidial keratoconjunctivitis caused by Septata intestinalis in a patient with acquired immunodeficiency syndrome.

PURPOSE: To examine and treat a patient with acquired immunodeficiency syndrome (AIDS) who had mildly hyperemic conjunctiva and epithelial keratopathy in both eyes. METHODS: The patient underwent conjunctival biopsy. The specimen was examined by transmission electron microscopy. RESULTS: Septata intestinalis was demonstrated to be the cause of keratoconjunctivitis in the patient. The keratoconjunctivitis resolved after three weeks of therapy with topical fumagillin. No organisms were seen on repeat conjunctival biopsy. CONCLUSIONS: Microsporidial keratoconjunctivitis in patients with AIDS can be caused by S. intestinalis. This condition appears to respond to topical fumagillin.

Microsporidial keratoconjunctivitis in a healthy patient with a history of LASIK surgery.

PURPOSE: To describe a case of microsporidia corneal infection in a HIV-negative patient who did not wear contact lenses. METHOD: Case report and review of literature. RESULTS: This is the first case report of a human immunodeficiency virus-negative individual, a non-contact lens wearer, with microsporidia infection. CONCLUSION: Microsporidia keratoconjunctivitis may occur in healthy subjects with no antecedent contact lens wear.

Emerging and reemerging infections. Progress and challenges in the subspecialty of infectious disease pathology.

Emerging and reemerging infections are attracting greater attention from the public health and medical communities. Pathologists and other physicians are increasingly aware of the importance of the subspecialty of infectious disease pathology as a tool for diagnosis, surveillance, and research of emerging infections. In this communication, we describe the role that infectious disease pathologists have played during the last 2 years in broadening our understanding of selected emerging infections, including such examples as new variant Creutzfeldt-Jakob disease and bovine spongiform encephalopathy, leptospirosis, microsporidiosis, Ebola hemorrhagic fever, and cyclosporiasis. The significance of providing pathology services, especially the autopsy, to patients with potentially hazardous communicable diseases is discussed with the supposition that it is unethical to exclude or withhold health care from a patient based on his or her underlying disease or on risk factors for acquiring a disease. The increasing occurrence of infectious diseases imported into the United States and other nations, including human immunodeficiency virus-1 group O, dengue fever, tuberculosis, malaria, diphtheria and cholera in immigrants and travelers, and Ebola virus in nonhuman primates, emphasizes the necessity for pathologists of having competence with infectious disease pathology. It is critical that new generations of pathologists not only be trained in the subspecialty of infectious disease pathology, but that they also be willing participants in the diagnosis and investigation of infectious diseases. The lack of training programs for infectious disease pathologists, as well as the deficiency in infectious disease pathology support for ongoing and future epidemiologic investigations and research, has led to the broadening of pathology services and initiation of a dedicated section of Infectious Disease Pathology at one of the nation's premier public health institutions, the Centers for Disease Control and Prevention in Atlanta, Ga. Together with preexisting groups of medical and veterinary infectious disease pathologists at universities, the Armed Forces Institute of Pathology, the US Army Medical Research Institute of Infectious Diseases, and the National Institutes of Health, this new program will significantly strengthen the capability of the United States to respond to future challenges of emerging and reemerging infections, both in this country and abroad.

Factors associated with microsporidial and cryptosporidial diarrhea in HIV infected patients.

Cryptosporidium and microsporidia are increasingly recognized as important agents of chronic diarrhea in human immunodeficiency virus (HIV) infected patients. These protozoa present clinical and biological similarities but coinfection with these two parasites seems uncommon in a population of diarrheic HIV infected patients in the Paris area (France), a comparison study was performed in order to clarify epidemiological differences between these protozoa. From November 1993 to December 1994, 26 microsporidial infected patients were compared to 28 cryptosporidial patients for various factors. Results of a multivariate logistic regression analysis showed that trips to tropical countries remained strongly associated with microsporidic compared with Cryptosporidium adjusted odds ratio [OR] = 4.6, 95% confidence interval [CI] 1.1-19.5). Thus, as compared with cryptosporidiosis, specific epidemiological factors could be associated with microsporidial transmission in tropical countries.

Unusual Enterocytozoon bieneusi genotypes and Cryptosporidium hominis subtypes in HIV-infected patients on highly active antiretroviral therapy.

Human immunodeficiency virus (HIV)-infected persons are commonly infected with Cryptosporidium species and Enterocytozoon bieneusi in both developed and developing countries, particularly patients with CD4+ cell counts below 200 cells/µL; 285 HIV-infected patients on highly active antiretroviral therapy (HAART) were enrolled in this study, and both stool and blood specimens were collected from participants. The stool specimens were analyzed and typed for E. bieneusi and Cryptosporidium spp. by polymerase chain reaction (PCR) and DNA sequencing. CD4 count was analyzed using flow cytometry. E. bieneusi and Cryptosporidium were detected in 18 (6.3%) and 4 (1.4%) patients, respectively. The E. bieneusi detected mostly belonged to a new genotype group that, thus far, has only been found in a few humans: genotype Nig4 in 2 patients and two new genotypes related to Nig4 in 12 patients. The Cryptosporidium detected included C. hominis (two patients), C. parvum (one patient), and C. felis (one patient), with the two C. hominis infections belonging to an unusual subtype family. Additional studies are required to determine whether some E. bieneusi genotypes and C. hominis subtypes are more prevalent in HIV patients on HAART.

HIV/AIDS-associated opportunistic protozoal diarrhea.

Human immunodeficiency virus (HIV) infection has altered both the epidemiology and outcome of enteric opportunistic parasitic infections. This study was done to determine the prevalence and species/genotypes of intestinal coccidian and microsporidial infections among HIV/AIDS patients with diarrhea and/or a history of diarrhea alternately with an asymptomatic interval, and their association with CD4 T cell count. This cross-sectional study was done from May 2010 to May 2011 in Shiraz University of Medical Sciences, South of Iran. A blood sample was obtained from HIV-positive patients for a CD4 T cell count upon enrollment. Sociodemographic data and a history of diarrhea were collected by interviewing 356 consecutive participants (273 males and 83 females). Whenever possible more than a fecal sample was collected from all the participants and examined for parasites using direct, physiological saline solution ethyl acetate, an acid-fast trichrome stain, nested polymerase chain reaction, and sequencing techniques for the detection, confirmation, and genotyping of Cryptosporidium spp., Cyclospora cayetanensis, Isospora belli, and intestinal microsporidia (Enterocytozoon bieneusi). The most common opportunistic and nonopportunistic pathogens were Cryptosporidium spp. (C. parvum and C. andersoni), E. bieneusi, Giardia lamblia, Sarcocystis spp., and Blastocystis homonis affecting 34, 8, 23, 1, and 14 patients, respectively. C. cayetanensis, I. belli, Enterobius vermicularis, and Hymenolepis nana were observed in few patients. A CD4 count <200 cells/µl was significantly associated with the presence of opportunistic parasites and diarrhea (p<0.05). Opportunistic intestinal parasites should be suspected in any HIV/AIDS patient with chronic diarrhea. Tropical epidemic nonopportunistic enteric parasitic infections among such patients should not be neglected in Iran.

Enterocytozoon bieneusi in Bovine Viral Diarrhea Virus (BVDV) infected and noninfected cattle herds.

Enterocytozoon bieneusi known as a causative agent of opportunistic infections instigating diarrhoea in AIDS patients was identified also in a number of immunocompetent patients and in a wide range of animals, including cattle. In the present study we tested if the Bovine Viral Diarrhea Virus (BVDV), the most common pathogen underlying immunosuppressive Bovine Viral Diarrhoea (BVD), can enhance the occurrence of opportunistic infections with E. bieneusi in cattle. Six dairy farms were investigated using ELISA to detect antibodies against or antigens arising from BVDV in collected sera. A total of 240 individual faecal samples from four age groups were examined for the presence of E. bieneusi by nested PCR. Sequence analysis of six E. bieneusi positive samples revealed the presence of the genotype I of E. bieneusi, previously described in cattle. The hypothesis expecting higher prevalence of E. bieneusi in BVDV positive cattle herds was not confirmed in this study; however this is the first description about E. bieneusi in cattle in the Czech Republic.