The diagnosis of toxoplasmosis is of great importance due to the damage caused by this parasite in immunosuppressed people or in pregnant women, the diagnosis of an active toxoplasmosis represents a sign to initiate a pharmacological treatment immediately. The diagnosis of Toxoplasma can be performed with direct methods through intraperitoneal inoculation of serum or cerebrospinal fluid, in susceptible mice evaluating the survival and detection of tachyzoites of biological samples. Indirect methods detecting the IgM and IgG isotypes against Toxoplasma have been the tools mostly used and had leaded to discriminate between an active and acute, from a chronic toxoplasmosis. Molecular methods actually Toxoplasma-DNA identification by molecular biology tests like the polymerase chain reaction (PCR) allow the direct detection of the parasite. Polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) have been used to identify three strain linages (type I, II and III). Recently, a high-resolution melting method was described to determine the genotype of the infection by Toxoplasma gondii directly from biological samples.
Part of the book: Toxoplasmosis