Congenital human toxoplasmosis, caused by the vertical transmission of the protozoan parasite Toxoplasma gondii during primary infections in pregnancy, was established as a distinct symptomatic complex around 1940. In 1948, the first robust serological diagnostic test was published. The severity of congenital toxoplasmosis flagged the disease as an area of concern for pediatricians and the budding field of perinatal medicine, and stimulated interdisciplinary research programs.
In 1975, the first nation-wide surveillance program for toxoplasmosis during pregnancy was started, as part of the general preventive care program for pregnant women and infants in the Austrian “Mutter-Kind-Paß.” Physicians who provided primary care for pregnant women, however, lacked the knowledge to interpret serological test results. This created a need for case-management recommendations and led to a paradoxical situation: the publication of two different and partially contradictory official guidelines.
I will analyze and discuss the underlying interpretation of the evidential basis of these guidelines as well as the inductive risks of the decisions to be made during case-management. For example, the capacity to predict potential pathologies based on serological tests was repeatedly discussed and weighed against the risk of wrong interpretations and their consequences. The demand to translate such specialists’ discourses lacking a clear consensus for the realm of public health and non-specialized clinical practice highlights the limits of this translational activity. By understanding the complexity of the validation and coordination efforts that contributed to the success (or failure) of an interdisciplinary biomedical community communicating with public health entities about infectious diseases, I aim to provide resources to contextualize and understand current debates about diagnostic validity as enforced, for example, by the ongoing pandemic.