IgA : Measurement of IgA antibody titers may also be useful in a diagnosis of congenital toxoplasmosis in a fetus or newborn because IgM production is often weak during this period and the presence of IgG antibodies may indicate passive transfer of maternal antibodies in utero. IgA antibodies however usually disappear by 7 months.In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be helpful for establishing etiology. Neuroimaging is warranted in AIDS patients presenting with these findings because intracranial toxoplasmic lesions have been reported in up to 29% of these patients who have toxoplasmic chorioretinitis. Prevention
Toxoplasma infection can be prevented in large part by:

cooking meat to a safe temperature (i.e., one sufficient to kill Toxoplasma)
peeling or thoroughly washing fruits and vegetables before eating
cleaning cooking surfaces and utensils after they have contacted raw meat, poultry, seafood, or unwashed fruits or vegetables
pregnant women avoiding changing cat litter or, if no one else is available to change the cat litter, using gloves, then washing hands thoroughly
not feeding raw or undercooked meat to cats to prevent acquisition of ToxoplasmaProlonged and intense rainfall periods are significantly associated with the reactivation of toxoplasmic retinochoroiditis. Changes promoted by this climatic condition concern both the parasite survival in the soil as well as a putative effect on the host immune response due to other comorbidities. Treatment
Small extramacular lesions (lesions not threatening vision) may be observed without treatment.
Darwins tubercle (or auricular tubercle) is a congenital ear condition which often presents as a thickening on the helix at the junction of the upper and middle thirds. History
This atavistic feature is so called because its description was first published by Charles Darwin in the opening pages of The Descent of Man, and Selection in Relation to Sex, as evidence of a vestigial feature indicating common ancestry among primates which have pointy ears. However, Darwin himself named it the Woolnerian tip, after Thomas Woolner, a British sculptor who had depicted it in one of his sculptures and had first theorised that it was an atavistic feature. Prevalence
The feature is present in approximately 10.4% of the Spanish adult population, 40% of adults in India, and 58% of Swedish school children. This acuminate nodule represents the point of the mammalian ear. The trait can potentially be bilateral, meaning present on both ears, or unilateral, where it is present on only one ear. There is mixed evidence in regard to whether the bilateral or unilateral expression is related to population, or other factors. Some populations express full bilateral, while others may express either unilateral or bilateral. However, bilateral appears to be more common than unilateral as it pertains to the expression of the trait. Inheritance
The gene for Darwins tubercle was once thought to be inherited in an autosomal dominant pattern with incomplete penetrance, meaning that those who possess the allele (version of a gene) will not necessarily present with the phenotype.