This PCR technique utilizes the 5 nuclease activity of Taq DNA polymerase to cleave a nonextendible, fluorescence-labeled hybridization probe during the extension phase of PCR. A second fluorescent dye, e.g., 6-carboxy-tetramethyl-rhodamine, quenches the fluorescence of the intact probe. The nuclease cleavage of the hybridization probe during the PCR releases the effect of quenching resulting in an increase of fluorescence proportional to the amount of PCR product, which can be monitored by a sequence detector.Toxoplasmosis cannot be detected with immunostaining. Lymph nodes affected by Toxoplasma have characteristic changes, including poorly demarcated reactive germinal centers, clusters of monocytoid B cells, and scattered epithelioid histiocytes. The classic triad of congenital toxoplasmosis includes: chorioretinitis, hydrocephalus, and intracranial arteriosclerosis. Other consequences include sensorineural deafness, seizures, and intellectual disability.Congenital toxoplasmosis may also impact a childs hearing. Up to 30% of newborns have some degree of sensorineural hearing loss. The childs communication skills may also be affected. A study published in 2010 looked at 106 patients, all of whom received toxoplasmosis treatment prior to 2.5 months. Of this group, 26.4% presented with language disorders. Treatment
Treatment is recommended for people with serious health problems, such as people with HIV whose CD4 counts are under 200 cells/mm3. Trimethoprim/sulfamethoxazole is the drug of choice to prevent toxoplasmosis, but not for treating active disease. A 2012 study shows a promising new way to treat the active and latent form of this disease using two endochin-like quinolones.
Wolf, Cowen and Page reviewed additional cases and concluded that T. gondii produced recognizable symptoms and could be transmitted from mother to child.The first adult case of toxoplasmosis was reported in 1940 with no neurological signs. Pinkerton and Weinman reported the presence of Toxoplasma in a 22-year-old man from Peru who died from a subsequent bacterial infection and fever.In 1948, a serological dye test was created by Sabin and Feldman based on the ability of the patients antibodies to alter staining of Toxoplasma. The Sabin Feldman Dye Test is now the gold standard for identifying Toxoplasma infection.Transmission of Toxoplasma by eating raw or undercooked meat was demonstrated by Desmonts et al. in 1965 Paris. Desmonts observed that the therapeutic consumption of raw beef or horse meat in a tuberculosis hospital was associated with a 50% per year increase in Toxoplasma antibodies. This means that more T. gondii was being transmitted through the raw meat. In 1974, Desmonts and Couvreur showed that infection during the first two trimesters produces most harm to the fetus, that transmission depended on when mothers were infected during pregnancy, that mothers with antibodies before pregnancy did not transmit the infection to the fetus, and that spiramycin lowered the transmission to the fetus.Toxoplasma gained more attention in the 1970s with the rise of immune-suppressant treatment given after organ or bone marrow transplants and the AIDS epidemic of the 1980s. Patients with lowered immune system function are much more susceptible to disease.