Epidemiological features of influenza in a large town of Romania during 1983.

Abstract Data supplied by the active influenza surveillance - including clinical, epidemiological and laboratory investigations - allowed the characterization of the particularities of an influenza outbreak caused by A(H3N2) virus in a large town of Romania in March 1983. The epidemiological impact of influenza in 1983 is discussed in the light of the complex relationships between the antigenic structure of circulating influenza strains and the profile of antiinfluenza immunity of the population.