Microsporidiosis Flashcards
What are microsporidia?
Microsporidia are protists related to fungi, characterized by a unique invasive organelle consisting of a single polar tube that coils around the interior of the spore.
What is the origin of microsporidia?
Microsporidia are likely zoonotic and/or waterborne in origin.
What is the significance of phylogenetic studies on microsporidia?
Phylogenetic studies place microsporidia with the Cryptomycota as the basal branch of the fungal kingdom.
List some microsporidia pathogens reported in humans.
- Encephalitozoon cuniculi
- Encephalitozoon hellem
- Encephalitozoon intestinalis
- Enterocytozoon bieneusi
- Trachipleistophora hominis
- Trachipleistophora anthropophthera
- Pleistophora species
- Vittaforma corneae
- Tubulonosema acridophagus
- Anncaliia connori
- Anncaliia vesicularum
- Anncaliia algerae
- Microsporidium sp.
What was the reported prevalence of microsporidiosis in people with HIV/AIDS before ART?
Prevalence rates varied between 2% and 70% among people with HIV/AIDS with diarrhea.
How has the incidence of microsporidiosis changed with ART?
The incidence of microsporidiosis has declined with the widespread use of effective ART.
Who is increasingly recognized to be affected by microsporidiosis aside from people with HIV?
Children, travelers, organ transplant recipients, contact lens wearers, and the elderly.
What CD4 T lymphocyte count is associated with clinical signs of microsporidiosis?
CD4 T lymphocyte (CD4) cell counts <100 cells/mm3.
What is the most common manifestation of microsporidiosis?
Gastrointestinal tract infection with diarrhea.
What other clinical manifestations can occur due to microsporidiosis?
- Encephalitis
- Ocular infection
- Sinusitis
- Myositis
- Disseminated infection
What is the association of E. bieneusi with symptoms?
Malabsorption, diarrhea, and cholangitis.
How can microsporidia be effectively diagnosed?
Through effective morphologic demonstration by light microscopy with specific staining methods.
What is required for visualization of microsporidia spores?
Magnification up to 1,000 times.
Name a useful stain for identifying microsporidia in stool.
Chromotrope 2R.
What should be examined if stool examination for microsporidiosis is negative?
A small bowel biopsy may be useful.
What are some preventive measures for people with HIV and low CD4 counts?
- Avoid untreated water sources
- Increase attention to hand washing and hygiene
- Avoid undercooked meat or seafood
- Limit exposure to infected animals
What is the key to preventing chronic microsporidiosis?
Initiate ART before severe immunosuppression occurs.
What should be managed in cases of microsporidiosis?
- Initiate or optimize ART
- Manage severe dehydration and malnutrition
- Use antimotility agents for diarrhea control
What is the best treatment option for GI infections caused by Enterocytozoon bieneusi?
ART and fluid support.
What is the recommended treatment for intestinal and disseminated microsporidiosis caused by organisms other than E. bieneusi?
Albendazole 400 mg PO twice daily for at least 14 days.
What is the recommended treatment for ocular infection caused by microsporidia?
Topical fumagillin and albendazole for systemic infection.
What is a consideration for discontinuing chronic maintenance therapy for non-ocular manifestations?
No signs and symptoms of microsporidiosis and sustained CD4 count >200 cells/mm3 for ≥3 months after ART.
What is the recommendation regarding albendazole use during pregnancy?
Not recommended for use during the first trimester.
Why should fumagillin not be used systemically in pregnant individuals?
It has an antiangiogenic effect.
What should be avoided during the first trimester of pregnancy?
- Azole antifungals
- Loperamide unless benefits outweigh risks
What potential risk is associated with opiate exposure in late pregnancy?
Neonatal respiratory depression and withdrawal.
