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microsporidiosis

n. infection by microsporidians

Wikipedia
Microsporidiosis

Microsporidiosis is an opportunistic intestinal infection that causes diarrhea and wasting in immunocompromised individuals ( HIV, for example). It results from different species of microsporidia, a group of microbial (unicellular) fungi.

In HIV infected individuals, microsporidiosis generally occurs when CD4+ T cell counts fall below 150.