evidence: Toxoplasmosis is a disease caused by the single-celled parasite Toxoplasma gondii (T. gondii). It is one of the most common parasitic diseases and infects nearly all warm-blooded animals, including pets and humans. Although cats are a necessary part of the life cycle of T. gondii, the parasite rarely causes clinical disease in them. While T. gondii seldomly causes significant symptoms in healthy adults either (see below for exceptions), the Centers for Disease Control and Prevention (CDC) has recently identified toxoplasmosis as one of five neglected parasitic infections of people due to its high prevalence. More than 60 million people in the U.S. are thought to be infected. [...] The most common symptoms of toxoplasmosis include fever, loss of appetite, and lethargy. Other symptoms may occur depending upon whether the infection is acute or chronic, and the location of the parasite in the body. In the lungs, T. gondii infection can lead to pneumonia, which will cause difficulty breathing that gradually worsens. Infections affecting the liver may cause a yellowish tinge to the skin and mucous membranes (jaundice). Toxoplasmosis can also affect the eyes and central nervous system (CNS), producing inflammation of the uvea, or pigmented part of the eye (uveitis), the retina, or the space between the lens and cornea (the anterior chamber) (Figure 2), abnormal pupil size and responsiveness to light, blindness, lack of coordination, heightened sensitivity to touch, personality changes, circling, head pressing, ear twitching, difficulty chewing and swallowing food, seizures, and loss of control over urination and defecation.