Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 29-30. (Budapest, 1997)

and abnormal bleeding time. Also, in this group, abnormal spinal fluid was encountered in 84%, retinochoroiditis in 66%, hypothermia in 20%, and convulsions in 18% of patients, suggesting early central nervous system involvement. Encephalitis has also been traced to toxoplasmosis in older children (Sabin 1941). In 108 babies with congenital toxoplasmosis, severe neurologic manifestations were found: retinochoroiditis (95%), abnormal spinal fluid (55%), convulsions (50%), intracranial calcification (50%), internal hydrocephalus (28%), fever (25%), and microcephaly (30%). The mortality rate was about 12%, and the sequelae observed over a four-year period in 100 patients included mental retardation (86%), convulsions (81%), spasticity and palsy (70%), severely impaired eyesight (63%), hydrocephalus or microencephaly (42%>), and deafness (16%). Only 11% of the babies were considered normal. However, most of these babies were referred for illness and, therefore, the more severe aspects of the disease are represented here (Remington and Desmonts 1983). The incidence of congenital toxoplasmosis has been estimated to be 3-6 cases per 1000 live births in "high-risk" countries, 1-2 cases per 1000 live births in "low-risk" countries, and approx. 2-3 cases per 1000 live births in Hungary. Prevention of congenital toxoplasmosis is a step-wise process. The first step is the reduction of the risk of infestation of women by adequate health education both before and during pregnancy. However, it is not so easy to reduce the infestation of pregnant women since this would demand a change in their living habits in order to avoid the multiple ways of toxoplasma transmission (Fig. 1), e.g. via contact with infected cat faeces, or eating insufficiently washed or unwashed raw vegetables and fruits contaminated with cat faeces, or the consumption of raw or undercooked meat containing tissue cysts (Foulon et al. 1988, Hall 1992, Szénási and Nagy 1996a, Szénási et al. 1996b). In addition, appropriate information about prevention should be given to all women of childbearing age before Fig. 1. Life cycle of, and infection by, Toxoplasma gondii