Toxoplasmosis (toxo) is an infection caused by the Toxoplasma gondii parasite, a single-celled organism that can infiltrate tissues and potentially harm the brain, particularly in fetuses and newborns. Although this parasite is widespread, with over 60 million carriers in the United States, many people remain unaware of it because the immune system typically prevents it from causing illness.The symptoms of toxoplasmosis resemble those of the flu, including fever, fatigue, headaches, swollen lymph nodes, and muscle aches, which may persist from a few days to several weeks. Transmission can occur when individuals touch their mouths after gardening, cleaning a cat's litter box, or handling anything that has been in contact with cat feces. Additionally, consuming raw or undercooked meat, particularly pork or lamb, or touching the mouth after handling such meat can also lead to infection.People with weakened immune systems are more susceptible to severe cases of toxoplasmosis. Those at high risk include children and adults with inherited immune deficiencies, individuals undergoing cancer treatment, those on systemic immunosuppressive therapy, organ transplant recipients on anti-rejection medication, and fetuses and newborns.Toxoplasma gondii is recognized as a teratogen, an agent capable of causing birth defects. If a pregnant woman contracts the infection, the parasite can pass through the placenta to the baby, sometimes resulting in serious outcomes. Infants born with toxoplasmosis may experience neurological issues, seizures, developmental delays, and partial or complete vision and hearing loss.