Three years of multi-laboratory external quality control for the molecular detection of Toxoplasma gondii in amniotic fluid in France.

Between 2002 and 2004, panels of amniotic fluid containing varying concentrations of Toxoplasma gondii were sent to up to 23 laboratories in France for molecular (PCR-based) detection as part of a national quality assurance initiative in the molecular prenatal diagnosis of toxoplasmosis. Participants were free to enroll and no fees were required. The general level of sensitivity was high, and the rate of false-positive reactions was relatively low. Considerable diversity among PCR methods and primers was revealed. This external quality assurance scheme provided the opportunity to improve laboratory practice and performance, and to increase communication among laboratories involved in making this diagnosis.