Isolated Positive Toxoplasma Gondii PCR in Blood

Toxoplasmosis in immunocompromised patients is a serious, life-threatening condition that requires rapid, appropriate treatment. Diagnosis is based on PCR, notably on blood samples. Systematic blood screening is carried out for patients most at risk, to detect the disease at an early stage. Detection of parasite DNA in blood in asymptomatic patients is possible, in the absence of Toxoplasma multiplication. It has previously been proposed a distinction of two entities: toxoplasmosis disease (clinical, biological and imaging evidence of toxoplasmosis) and toxoplasmosis infection (positive PCR in the blood in the absence of clinical or radiological evidence, without progression to toxoplasmosis). Since the clinical signs of toxoplasmosis are often aspecific, a positive PCR may be the first warning result, making it difficult to determine whether the patient will progress to toxoplasmosis disease or toxoplasmosis infection.

In collaboration with the French National Reference Center for toxoplasmosis, we are proposing a retrospective multicenter study to identify possible clinical, biological or imaging criteria pointing to toxoplasmosis disease or toxoplasmosis infection as soon as the first T. gondii PCR result is positive in the blood.