Anncaliia algerae microsporidial myositis

Case Report: The Use of In Vivo Confocal Microscopy for Diagnosis and Monitoring in a Rare Case of Ancaliia algerae Microsporidial Keratitis in New South Wales, Australia

We describe the successful management of Ancaliia Algerae microsporidial keratitis in an immunosuppressed 54-year-old woman with refractory linear IgA disease. The case highlights the challenges in diagnosis and management of this infection in immunocompromised individuals and emphasizes the usefulness of in vivo confocal microscopy as a novel, noninvasive tool to aid in the diagnosis and monitoring of microsporidial keratitis. We also discuss the possible mode of acquisition of this rare infection.

Microsporidial myositis, keratitis and hypercalcaemia in a cystic fibrosis lung transplant recipient

A man in his 50s was admitted with 4 months of myalgia, headaches, hypercalcaemia and declining renal function on a background of lung transplantation for cystic fibrosis 5 years prior. MRI confirmed myositis and a muscle biopsy revealed invasive muscular microsporidial infection. Positron emission tomography(PET)/CT revealed widespread dissemination of the infection. Albendazole was commenced and after a 1 week systemic inflammatory response syndrome, the patient made a significant recovery and was discharged home. PCR testing confirmed the species as Anncaliia algerae, which is known to infect mosquitoes, larvae and contaminate water supplies. This case highlights the need to relentlessly pursue a diagnosis and to consider atypical pathology in immune compromised patients. A tissue sample yielded highly beneficial and unexpected results. A multispecialty approach was essential given the varied infection manifestations, which included myositis, keratitis and possible central nervous system, vocal cord, parapharyngeal and renal involvement.

Anncaliia algerae Microsporidiosis Diagnosed by Metagenomic Next-Generation Sequencing, China

We report a case of Anncaliia algerae microsporidia infection in an immunosuppressed kidney transplant recipient in China. Light microscopy and transmission electron microscopy initially failed to identify A. algerae, which eventually was detected by metagenomic next-generation sequencing. Our case highlights the supporting role of metagenomic sequencing in early identification of uncommon pathogens.

Current Therapy and Therapeutic Targets for Microsporidiosis

Microsporidia are obligate intracellular, spore-forming parasitic fungi which are grouped with the Cryptomycota. They are both opportunistic pathogens in humans and emerging veterinary pathogens. In humans, they cause chronic diarrhea in immune-compromised patients and infection is associated with increased mortality. Besides their role in pébrine in sericulture, which was described in 1865, the prevalence and severity of microsporidiosis in beekeeping and aquaculture has increased markedly in recent decades. Therapy for these pathogens in medicine, veterinary, and agriculture has become a recent focus of attention. Currently, there are only a few commercially available antimicrosporidial drugs. New therapeutic agents are needed for these infections and this is an active area of investigation. In this article we provide a comprehensive summary of the current as well as several promising new agents for the treatment of microsporidiosis including: albendazole, fumagillin, nikkomycin, orlistat, synthetic polyamines, and quinolones. Therapeutic targets which could be utilized for the design of new drugs are also discussed including: tubulin, type 2 methionine aminopeptidase, polyamines, chitin synthases, topoisomerase IV, triosephosphate isomerase, and lipase. We also summarize reports on the utility of complementary and alternative medicine strategies including herbal extracts, propolis, and probiotics. This review should help facilitate drug development for combating microsporidiosis.

Myositis Caused by Trachipleistophora hominis in a Person With Human Immunodeficiency Virus: The First Case in Thailand

Background

To date, cases of extraintestinal micro-sporidiosis have been increasingly reported in both otherwise healthy and immunocompromised individuals. Among them, microsporidial myositis is very rare. To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a patient with human immunodeficiency virus (HIV) in Thailand.

Case report

A Thai man with HIV presented with fever and muscle pain at both anterior thighs and left arm for 3 months. Muscle biopsy was performed, and pathology exhibited neutrophil infiltration and focal aggregations of microsporidial spores. The 18S ribosomal RNA sequence revealed the species of this microsporidium as T hominis, and albendazole of 800mg/day was initiated. He gradually improved, and was discharged home 6 weeks after hospitalization.

Conclusions

To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a person with HIV in Thailand.

Microsporidiosis in Humans

Microsporidia are obligate intracellular pathogens identified ∼150 years ago as the cause of pébrine, an economically important infection in silkworms. There are about 220 genera and 1,700 species of microsporidia, which are classified based on their ultrastructural features, developmental cycle, host-parasite relationship, and molecular analysis. Phylogenetic analysis suggests that microsporidia are related to the fungi, being grouped with the Cryptomycota as a basal branch or sister group to the fungi. Microsporidia can be transmitted by food and water and are likely zoonotic, as they parasitize a wide range of invertebrate and vertebrate hosts. Infection in humans occurs in both immunocompetent and immunodeficient hosts, e.g., in patients with organ transplantation, patients with advanced human immunodeficiency virus (HIV) infection, and patients receiving immune modulatory therapy such as anti-tumor necrosis factor alpha antibody. Clusters of infections due to latent infection in transplanted organs have also been demonstrated. Gastrointestinal infection is the most common manifestation; however, microsporidia can infect virtually any organ system, and infection has resulted in keratitis, myositis, cholecystitis, sinusitis, and encephalitis. Both albendazole and fumagillin have efficacy for the treatment of various species of microsporidia; however, albendazole has limited efficacy for the treatment of Enterocytozoon bieneusi. In addition, immune restoration can lead to resolution of infection. While the prevalence rate of microsporidiosis in patients with AIDS has fallen in the United States, due to the widespread use of combination antiretroviral therapy (cART), infection continues to occur throughout the world and is still seen in the United States in the setting of cART if a low CD4 count persists.

Fatal disseminated Anncaliia algerae myositis mimicking polymyositis in an immunocompromised patient

We report the first New Zealand case of Anncaliia algerae myositis in a 55-year-old man with a history of psoriatic arthritis, treated with long-term immunosuppressive therapy. He resided in the city of Rotorua, which is famous for geothermal hot springs. A vastus lateralis muscle biopsy was performed to investigate the cause of an unexplained myositis. Light microscopy demonstrated a necrotizing myositis with scattered clusters of ovoid spores within the myocyte cytoplasm resembling microsporidia. DNA analysis by PCR and electron microscopy confirmed microsporidial myositis with features characteristic of A. algerae. Immunosuppressive drugs were stopped and the patient was treated with cholestyramine wash and albendazole. The patient deteriorated with involvement of bulbar and respiratory muscles requiring intensive care and ventilation. He died 3 weeks after diagnosis. Post-mortem examination of skeletal muscle from tongue and intercostal muscles also revealed numerous organisms confirming disseminated disease.

Cutaneous microsporidiosis in an immunosuppressed patient

Microsporidia are a group of obligate intracellular parasites that naturally infect domestic and wild animals. Human microsporidiosis is an increasingly recognized multisystem opportunistic infection. The clinical manifestations are diverse with diarrhea being the most common presenting symptom. We present a 52-year-old woman with a history of amyopathic dermatomyositis complicated by interstitial lung disease managed with mycophenolate mofetil and hydroxychloroquine who presented with a 7-month history of recurrent subcutaneous nodules as well as intermittent diarrhea and chronic sinusitis. A punch biopsy showed superficial and deep lymphocytic and granulomatous dermatitis with focal necrosis. Tissue stains for microorganisms revealed oval 1 to 3 μm spores within the necrotic areas in multiple tissue stains. Additional studies at the Centers for Disease Control and Prevention confirmed cutaneous microsporidiosis. This case is one of very few confirmed examples of cutaneous microsporidiosis reported in the literature.

Development of Anncaliia algerae (Microsporidia) in Drosophila melanogaster

Representatives of the genus Anncaliia are known as natural parasites of dipteran and coleopteran insects, amphipod crustaceans, but also humans, primarily with immunodeficiency. Anncaliia algerae-caused fatal myositis is considered as an emergent infectious disease in humans. A. (=Nosema, Brachiola) algerae, the best studied species of the genus, demonstrates the broadest among microsporidia range of natural and experimental hosts, but it has never been propagated in Drosophila. We present ultrastructural analysis of development of A. algerae in visceral muscles and adipocytes of Drosophila melanogaster 2 wk after per oral experimental infection. We observed typical to Anncaliia spp. features of ultrastructure and cell pathology including spore morphology, characteristic extensions of the plasma membrane, and presence of "ridges" and appendages of tubular material at proliferative stages. Anncaliia algerae development in D. melanogaster was particularly similar to one of A. algerae and A.(Brachiola) vesicularum in humans with acute myositis. Given D. melanogaster is currently the most established genetic model, with a fully sequenced genome and easily available transgenic forms and genomic markers, a novel host-parasite system might provide new genetic tools to investigate host-pathogen interactions of A. algerae, as well to test antimicrosporidia drugs.

Microsporidial myositis in adult-onset immunodeficiency: case-based review

Polymyositis is a diagnosis of exclusion. In patients with odd features, it can be of infective etiology. A high index of suspicion is required for diagnosis. A 55-year-old gentleman presented with gradual-onset proximal muscle weakness. Examination revealed mild distal weakness but no rash. Muscle enzymes were raised and tests for autoantibodies were negative. Biopsy revealed microsporidiosis. In view of this unusual infection, immunodeficiency was considered and he was found to have lymphopenia which antedated his illness. Later, he developed cranial nerve palsies due to multiple lesions in the pons. In addition, he had Cytomegalovirus viremia. Literature was reviewed to identify 20 cases of microsporidial myositis, its presentation, underlying immunodeficient state, and clinical course. Infective polymyositis should be considered in a patient with paucity of clinical and serological autoimmune features. Lymphopenia can point to underlying immunodeficiency. CMV infection could be the contributor to or bystander-effect of idiopathic lymphopenia.

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.

Anncaliia algerae Microsporidial Myositis, New South Wales, Australia

We describe the successful management of Anncaliia algerae microsporidial myositis in a man with graft versus host disease after hemopoietic stem cell transplantation. We also summarize clinical presentation and management approaches and discuss the importance of research into the acquisition of this infection and strategies for prevention.

Practical Guidance for Clinical Microbiology Laboratories: Laboratory Diagnosis of Parasites from the Gastrointestinal Tract

This Practical Guidance for Clinical Microbiology document on the laboratory diagnosis of parasites from the gastrointestinal tract provides practical information for the recovery and identification of relevant human parasites. The document is based on a comprehensive literature review and expert consensus on relevant diagnostic methods. However, it does not include didactic information on human parasite life cycles, organism morphology, clinical disease, pathogenesis, treatment, or epidemiology and prevention. As greater emphasis is placed on neglected tropical diseases, it becomes highly probable that patients with gastrointestinal parasitic infections will become more widely recognized in areas where parasites are endemic and not endemic. Generally, these methods are nonautomated and require extensive bench experience for accurate performance and interpretation.

Successful Treatment of Disseminated Anncaliia algerae Microsporidial Infection With Combination Fumagillin and Albendazole

Anncaliia algerae myositis is a life-threatening, emerging microsporidiosis among immunocompromised hosts. We report a case of disseminated A algerae infection in a man previously treated with alemtuzumab. Due to failure of albendazole-based therapy, fumagillin was added as a novel approach to management, with a good clinical response and patient survival.

Microsporidia - Emergent Pathogens in the Global Food Chain

Intensification of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aquatic and terrestrial hosts, many of which are vulnerable to epizootics, and all of which are crucial for the stability of the animal-human food chain. Mass rearing and changes in global climate may exacerbate disease and more efficient transmission of parasites in stressed or immune-deficient hosts. Further, human microsporidiosis appears to be adventitious and primarily associated with an increasing community of immune-deficient individuals. Taken together, strong evidence exists for an increasing prevalence of microsporidiosis in animals and humans, and for sharing of pathogens across hosts and biomes.

Microsporidial polymyositis in human immunodeficiency virus-infected patients, a rare life-threatening opportunistic infection: clinical suspicion, diagnosis, and management in resource-limited settings

INTRODUCTION

Microsporidial myositis is a rare opportunistic infection that has been reported in HIV-infected and HIV-uninfected immunocompromised patients.

METHODS

In this study we present a retrospective analysis of 5 cases of microsporidial myositis in HIV-infected patients, including the clinical, laboratory, and histologic features, and a review of the literature.

RESULTS

Five young men with HIV infection [median CD4 count of 20 cells (range 14-144)/mm(3) ] who presented with signs and symptoms suggestive of myositis underwent EMG-NCV and muscle biopsy, which revealed signs compatible with microsporidial myositis. Early and aggressive treatment led to improvement in 3 patients. Two of the 5 patients died due to a delay in diagnosis, because the spores were mistaken for Candida without confirmatory stains or a high index of suspicion.

CONCLUSIONS

Myositis in HIV-infected patients with low CD4 counts should be evaluated using muscle biopsy. A high index of suspicion is required for early diagnosis of microsporidial myositis in HIV-infected patients. Early diagnosis and immediate, aggressive treatment are the keys to favorable outcomes in these patients.

Analysis of the beta-tubulin gene and morphological changes of the microsporidium Anncaliia algerae both suggest albendazole sensitivity

The Microsporidium, Anncaliia algerae, an obligate intracellular parasite, has been identified as an opportunistic human pathogen, but treatment has not been evaluated for infections with this organism. Albendazole, an antitubulin polymerization drug used against parasitic worm infections, has been the medication of choice used to treat some microsporidial infections affecting humans, with varying results ranging from clearing infection (Encephalitozoon) to resistance (Enterocytozoon). This study illustrates the effect of albendazole treatment on A. algerae infection in Rabbit Kidney (RK13) cells and Human Fetal Lung (HFL-1) fibroblasts. Albendazole appears to have an attenuating effect on A. algerae infection and albendazole's IC50 in RK13 cells is 0.1 μg/ml. Long-term treatment inhibits up to 98% of spore production, but interrupting treatment reestablishes the infection without new exposure to the parasite as supported by microscopic observations. The parasite's beta-tubulin gene was purified, cloned, and sequenced. Five of the six specific amino acids, associated with benzimidazole sensitivity, are conserved in A. algerae. These findings suggest that A. algerae is sensitive to albendazole; however, the organism is not completely cleared from cultures.