CD40LG and infection: These serological profiles reflect recent or current infection, with a risk of foetal transmission, particularly during the first two trimesters.6,20 In the absence of an IgG-avidity test, it remains difficult to distinguish acute infection, reinfection or persistence of IgM.9,10 However, several authors recommend that, in cases of IgM positivity, treatment with spiramycin be initiated early, accompanied by close ultrasound monitoring, even in the absence of confirmation by IgG-avidity testing.12