Microsporidia infections are newly-recognized opportunistic infections that often found in AIDS patients. It infects human by the production on spores which are tiny and difficult to spot using convectional microscopic techniques. Spores contains polar tubules which acts as extrusion mechanisms to introduce spore contents into new host cell.
Criteria for classificiation include characterisitcs which vary among genera and species, such as size of spores, configuration of the nuclei in the spores, and the number of polar tubile coils within the spore.
The spores measures to 1.5 to 4.0 micrometers and contains polar tubules which are extrusion mechanisms for delivery of sporoplasm to the host.
Infection takes place after the ingestion of spores when the spores pass the duodenum. Once inside a suitable host cell, it multiplies extensively within the cytoplasm. Intracellular mutliplication involves binary fission (merogony) and a sporogony (a phrase culminating in spore formation). Parasites are spread from cell to cell, causing death of many cells as well as local inflammation. After sporogony may be excreted into the environment thus continuing the cycle.
AIDS patients who are diagnoised with such infection are usually marked by persistent and debilitating diarrhea similiar to patients with cryptosporidiosis (http://www.mamashealth.com/crypto.asp), cyclosporiasis (http://healthlink.mcw.edu/article/954992798.html) or isosporiasis (http://www.aegis.com/topics/oi/oi-isosporiasis.html).
Treatment and Prevention:
There are no specific recommendations that exist for prevention of infection, basically good personal hygiene and careful infection control practices thus preventing some infections.