Trichomonas tenax

Trichomonas tenax, or oral trichomonas, is a species of Trichomonas commonly found in the oral cavity of humans. Routine hygiene is generally not sufficient to eliminate the parasite, hence its Latin name, meaning "tenacious". The parasite is frequently encountered in periodontal infections, affecting more than 50% of the population in some areas, but it is usually considered insignificant. T. tenax is generally not found on the gums of healthy patients. It is known to play a pathogenic role in necrotizing ulcerative gingivitis and necrotizing ulcerative periodontitis, worsening preexisting periodontal disease. This parasite is also implicated in some chronic lung diseases; in such cases, removal of the parasite is sufficient to allow recovery (Mussaev 1976).