Of the 179 participants, 19 were seropositive (phase 2 IgG titre ≥1:64 in all cases, phase 2 IgM ≥ 1:48 also in three cases) and 10 presented a profile indicative of an acute infection (phase 2 IgG ≥ 1:256, of whom the three with phase 2 IgM ≥ 1:48). The gene discussed is CD40LG; the disease is infection.