Project Details

E.W. "Al" Thrasher

Status: Funded - Open

Prevention of congenital toxoplasmosis: Feasibility of prenatal screening using point-of-care tests

Yvonne (Bonnie) Maldonado, MD

Summary

BACKGROUND: Congenital Toxoplasmosis (CT) is a parasitic disease that affects ~190,000 infants/year worldwide and 300-400 infants/year in the US. Children with CT can have severe clinical manifestations; however, currently, pregnant women in the US and other parts of the world are not routinely screened and treated, although CT is clearly a preventable disease.

GAP: Point-Of-Care (POC) tests for Toxoplasmosis are already commercially-available in some countries; however, large scale rigorous validation in the US, where different T. gondii strains are circulating, against reference-gold-standard tests and against a wide range of Toxoplasmosis related clinical scenarios has not been previously performed.

HYPOTHESIS: POC tests that are accurate, rigorously validated and inexpensive, could be a cost-saving alternative to standard-diagnostics making universal-prenatal-screening a feasible preventive strategy to decrease the burden of disease from CT.

METHODS: Aim1: Validation in the US of the diagnostic performance of three inexpensive, already commercially-available POC-tests for Toxoplasmosis that are based on lateral-flow-chromatographic-immunoassay technology, detect T.gondii IgG/IgMs (separately or combined) in serum or whole blood. In a retrospective-validation-cohort-study we will use sera from the CDC (n=100 sera), the Palo-Alto-Medical-Foundation-Toxoplasma-Serology-Laboratory (n=150 sera) and the National-Collaborative-Chicago-based-Congenital-Toxoplasmosis-Study (NCCCTS), previously tested with reference-gold-standard tests. Aim2: Explore the feasibility in the US of a POC-test based Prenatal-Screening Program for Toxoplasmosis. In this prospective pilot-prenatal screening cohort study, we will enroll in the OB/GYN Department of the University of Chicago consenting pregnant-women to monthly Toxoplasmosis prenatal-screening throughout gestation both with a POC-test and Standard Laboratory Toxoplasma IgG/IgM.

RESULTS: Pending.

IMPACT: Identification of accurate, rigorously validated POC-tests for Toxoplasmosis that cost only few $ per test, can transform the field of diagnosis of gestational acquisition of T.gondii and CT in the US and worldwide. Moreover, proof of the feasibility of a POC-test-based Prenatal-Screening for Toxoplasmosis in the US will be a landmark-study to set up the foundations for future large-scale prenatal-screening to protect pregnant women and their children.

Publications:

Evaluation of Three Point-of-Care (POC) Tests for Detection of Toxoplasma IgG and IgM in the United States: Proof of Concept and Challenges

Rapid inexpensive, fingerstick, whole-blood, sensitive, specific, point-of-care test for anti-Toxoplasma antibodies.

Global initiative for congenital toxoplasmosis: an observational and international comparative clinical analysis.