[Seroepidemiological considerations on the influenza a in Umbria (1978) (author's transl)].

The authors studied the seroepidemiology of influenza virus A/Victoria/3/75 (H3N2) and A/URSS/90/77 (H1N1) in Umbria, in 1978. The percentage of seroprotection against the subtype H3N2 results low and in such do not inhibit the diffusion of this subtype during the next winter season. The study of seroepidemiology of subtype H1N1 demonstrated that this subtype circulated in Umbria in the winter 1977-78 and that the conditions exist for its circulation.