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Trichomoniasis is a sexually transmitted infection caused by Trichomonas vaginalis.
It is a single-celled, anaerobic protozoan that lacks mitochondria and contains hydrogenosomes, which generate energy under anaerobic conditions within the human host.
Transmission occurs through direct sexual contact, after which the parasite colonizes the lower reproductive tract.
This parasite exists only in the trophozoite stage, which replicates asexually by binary fission.
In females, trophozoites adhere to the vaginal epithelium using surface adhesins.
Adhered trophozoites secrete cytotoxic proteins that degrade cellular junctions.
This results in cellular apoptosis and sloughing of epithelial cells, leading to mucosal inflammation and tissue damage.
The parasite also disrupts the normal vaginal microbiota.
Damage to epithelial cells increases the host’s susceptibility to other sexually transmitted infections, including HIV.
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