Toxoplasmosis

Toxoplasmosis is one of the quietest infections there is. Most people who carry it never notice. Perhaps a phase of inexplicable fatigue, something like a mild flu that never quite erupts — and then it's over. The parasite Toxoplasma gondii remains nonetheless. It retreats into the cells, makes itself invisible, and lives on without your body ever fully ridding itself of it.

It is precisely in this silence that the distinctiveness of this symptom lies. Other infections rage and pass. Toxoplasmosis sneaks in and stays — usually without causing trouble, sometimes with serious consequences when a pregnant woman contracts it for the first time during pregnancy. A quiet lodger, living in concealment, becoming visible only under certain conditions.