Protozoa - Toxoplasma gondii: Toxoplasmosis

Transmitted via ingestion of cysts in undercooked meat or shellfish, or ingestion of oocysts in cat feces; it can also be transmitted congenitally, which is why pregnant women are often advised to avoid unfamiliar cats. Be aware that the "T" in TORCHeS infections is for "toxoplasmosis". It's estimated that 30% of the human population is infected with Toxoplasma gondii; few people experience illness. In those who do get sick, symptoms can be mild or severe. Mild cases: Patients experience flu-like symptoms with swollen glands and muscle aches that last for a month or longer. Severe cases: the brain and eye can be infected; dissemination to the CNS is more common in patients with immunosuppression. Toxoplasma gondii is a common cause of encephalitis in AIDS patients, especially in older patients, often due to reactivation of earlier infection. In the image, we can see that the encephalitis often manifests with multiple ring-enhancing brain abscesses. Congenital toxoplasmosis during the first trimester often leads to stillbirth; after the first trimester, infection is associated with the congenital (aka, classic) triad: Chorioretinitis (the most common outcome), hydrocephalus, and intracranial calcifications. Hill, D., and J. P. Dubey. "Toxoplasma Gondii: Transmission, Diagnosis and Prevention." Clinical Microbiology and Infection 8, no. 10 (October 1, 2002): 634–40. https://doi.org/10.1046/j.1469-0691.2002.00485.x. Prevention, CDC-Centers for Disease Control and. "CDC - Toxoplasmosis - General Information - Frequently Asked Questions (FAQs)," October 2, 2018. https://www.cdc.gov/parasites/toxoplasmosis/gen_info/faqs.html. Tenter, Astrid M., Anja R. Heckeroth, and Louis M. Weiss. "Toxoplasma Gondii: From Animals to Humans." International Journal for Parasitology 30, no. 12–13 (November 2000): 1217–58. https://www.cdc.gov/dpdx/toxoplasmosis/index.html