Acanthamoeba is a tiny amoeba that thrives in soil, dust, and various sources of fresh water, such as lakes, rivers, hot springs, and hot tubs. It can also be found in brackish and sea water, as well as in heating, ventilation, and air conditioning systems, including humidifiers. This organism can penetrate the skin through cuts or wounds or enter the body through the nostrils. Once inside, it can move to the brain and other areas via the bloodstream. Poor contact lens hygiene, such as improper storage and disinfection, can lead to Acanthamoeba entering the eye and causing an infection. One particularly severe infection caused by Acanthamoeba is granulomatous amebic encephalitis, which presents symptoms like headaches, stiff neck, nausea, vomiting, confusion, loss of balance, seizures, and coma, potentially leading to death over several weeks. These infections are more common in individuals with weakened immune systems or chronic illnesses. While eye and skin infections can generally be treated, brain infections are almost always fatal.
