Microsporidiosis A07.8

clinical picture caused by an infection with microsporidia in predominantly immunocompromised patients. The transmission occurs by uptake of unicellular, environmentally stable spores from animals to humans by smear infection (Note: previously evaluated as protozoan infection).

Microsporidia are unicellular, obligate intracellular, mitochondria-free fungi of which there are about 1200 species. Microsporidia were formerly classified as protozoa. They are pathogens of microsporidiasis in immunocompetent humans.

Microsporidia can reach a size of a few µm (2-12 µm). Microsporidia usually parasitize intracellularly in representatives of many animal strains.

As pathogens only a few pathogens appear:

• Enterocytozoon bieneusi
• intestinal encephalitozoon
• Encephalitozoon cuniculi
• Microsporidium africanum
• vittaforma corneum

Fecal-oral transmission (person to person; through contaminated water).

In healthy people, a multiplication of the fungi in the intestine is hardly possible. However, in HIV-infected persons (T-helper number a100/μl) they can multiply in the intestinal epithelium (less frequently in conjunctival cells). Especially Encephalitozoon bieneusi and E. intestinalis and are then the cause of a chronic aqueous diarrhoea persisting for months with malabsorption, gfls. cholangitis, hepatitis, keratoconjunctivitis, peritonitis, sinusitis. Weight loss up to the wasting syndrome, "slim disease" in East Africa. Very rare is dissemination with encephalitis.

Vittaforma corneum in particular can cause ocular infections (punctiform keratopathy with redness and irritation); the development of stromal keratitis is also possible.

Microscopic detection of the pathogens in biopsy samples, stool, urine, other secretions or cornea scrapings; fluorochrome or trichrome staining also possible. PCR detection.

There is no specific therapy.

In patients with AIDS initiation or optimization of antiretroviral therapy (ART)

The administration of albendazole ((Eskazole®: 400 mg p. o. for adults or 7.5 mg/kg for children for 2 to 4 weeks) or fumagillin (mycotoxin) is helpful.

In keratoconjunctivitis, albendazole 400 mg p.o. 2x/day + fumidil B eye drops (bicyclohexyl-ammonium fumagillin) 3 mg/ml every 1-2 hours. Topical fluoroquinolones, as well as topical voriconazole, were effective in some patients. If topical and systemic therapy are ineffective, keratoplasty may be considered.

1. Didier ES, Weiss LM (2006) Microsporidiosis: current status. Curr Opin Infect Dis 19: 485

2. Han B et al (2018) Therapeutic targets for the treatment of microsporidiosis in humans. Expert Opinion Ther Targets 22:903-915.

3. Field AS et al. (2015) Intestinal microsporidiosis. Clin Lab Med 35:445-459.

4. Leroy J et al (2018) Case Report: Ocular Microsporidiosis: Case in a Patient Returning from India and Review of the Literature. At J Trop Med Hyg 99:90-93.

5. Ramanan P et al (2014) Extraintestinal microsporidiosis. J Clin Microbiol 52:3839-3844.

6. Weber R, Bryan RT, Schwartz DA, Owen RL (1994) Human microsporidia infections. Clin Microbiol Rev 7: 426