[The epidemiological characteristics of influenza in a large urban center (B.) of Romania in 1991].
The peculiarities of the 1991 influenza epidemics in a big urban centre (B.) of Romania were evaluated through clinical and epidemiological active survey and laboratory assays. The results revealed the low rate of endemic morbidity and its significant risk during the fourth trimester as compared to the first, the important implication of the infant population in maintaining the endemic morbidity and of the less than one year old children in the seasonal peaks of the first and fourth trimesters. The laboratory assays revealed the simultaneous circulation but with variable intensity of type A(H3N2), A(H1N1) and B influenza viruses, inducing a high humoral specific protection level in the population. So the risk is low of an important epidemics during 1992. The opportunity is discussed of the prophylactic vaccination with type A(H3N2), A(H1N1) and B circulating strains of all high risk groups, especially of the preschool children from collectivities.