Chronic toxoplasmosis with negative dye test?

Toxoplasma antibodies and spontaneous abortion

One hundred and fifty-two women with spontaneous abortion were investigated by hemagglutination (HA) and immunofluorescence antibody (IFA) tests for toxoplasmosis. In 48 cases, quantitive immunoglobulin (Ig) studies and mouse inoculation with gestational material were performed. Positive toxoplasma antibody titers were observed in 62 cases (40.8%) using HA and in 52 cases (38.2%) using IFA. This prevalence was significantly higher than that observed in 80 normal women who served as controls. Toxoplasma gondii was isolated in two cases. No correlation was found between antibody titers and IgG, IgM or IgA levels. We conclude that toxoplasmosis should be considered as the cause of abortion when a patient's antibody titer exceeds 1:256.

[Histochemistry of the carbohydrate metabolism in cysts of Toxoplasma gondii (author's transl)]

Mice were infected with cysts of the ALT strain Toxoplasma by intraperitoneal injection. After 2-8 weeks disseminated cysts could be demonstrated in the brain tissue. All cysts showed identical histochemical characteristics, independent of their sizes or their cell number. The encysted organisms were intensely stained after the PAS-reaction. This polysaccharide is highly diastase and acid resistant. Glycogen synthetase activity could not be demonstrated, but phosphorylase activity was very high. The energy metabolism was characterized by a high lactate dehydrogenase activity, whereas the reaction for succinate dehydrogenase activity only leads to sparse deposits of reaction products. The carbohydrate content is interpreted to be not only a store of energy substrate but also a store of biosynthetic substrate. It is assumed that a part of the liberated glucose at high activities of G-6-P-DH and 6-P-G-DH is metabolized by the hexose monophosphate shunt, the pentoses of which may contribute to nucleic acid synthesis which is necessary for the proliferation of the encysted organisms.

Toxoplasmin sensitivity: subnormality and environment

The incidence of positive toxoplasmin skin test among subnormals in hospital was compared with that in subnormals attending day training centres and among normal children taken into County Council children's homes. Twelve out of 120 subnormals below the age of 20 attending day training centres were positive to the test, and 23 were positive out of 233 subnormals of the same age tested in hospital.

There was only 1 positive out of 71 children under the age of 18 in the County Council children's homes, compared with 29 out of 296 subnormals of this age who were tested.

The incidence of positive skin test among 115 mongols under the age of 50 was about 11% in each age range, whereas that in 709 other subnormals rose from 5% in those below the age of 10 to 30% in those over the age of 30.

Although factors similar to those causing admission of normal children to County Council care often determine the admission of subnormals to hospital, the children in County Council homes did not share the high incidence of infection which was found in subnormals.

It is suggested that the majority of infections among subnormal children are postnatally acquired. Since the incidence was the same in subnormals living at home as among those in hospital it is suggested that some personal habit commoner among subnormal than among normal children exposes the subnormals to an increased risk of infection.