[The epidemiological characteristics of influenza in a large urban center (B.) of Romania in 1991]. / Caractéristiques épidémiologiques de la grippe dans un grand centre urbain (B.) de Roumanie, en 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.

[The evolutionary characteristics of an influenza epidemic in a large urban center (B.) of Romania between 1988 and 1990]. / Caractéristiques de l'évolution de l'épidémie de grippe dans un grand centre urbain (B.) de Roumanie dans l'intervalle 1988 à 1990.

The report presents the peculiar characteristics of influenza epidemics in a big urban centre (B.) of Romania, between 1988 and 1990, surveyed by clinical, epidemiological and laboratory methods. Among the peculiarities of the epidemics: the low rate of endemic morbidity, the seasonal and preseasonal peaks, the very high implication of infantile population in influenza A(H3N2), A(H1N1) and B virus circulation, as well as the high level of mass specific humoral protection against these viruses. Elements of epidemiologic prognosis are suggested for 1991. Opportunity of vaccine prophylaxis using WHO recommended virus strains of the three types: A(H3N2), A(H1N1) and B, for risk groups is discussed.

Epidemiological aspects of the evolution of influenza infections in a large urban centre (B.) in Romania in 1988.

The study describes the peculiarities of the influenza infection evolution, in 1988, in a large urban centre, B., in Romania, as they result from the active surveillance of the epidemiological process of influenza and other viral respiratory tract infections, by means of a complex methodology based on clinical-epidemiological and laboratory techniques. The low endemic morbidity, the evolution of these seasonally ascendant specific incidence, the endemic aspect of influenza infection being maintained as a consequence of its predominance in infants and children, the clinically mild form of the outbreaks, all these are specific elements of the epidemiologic impact in the surveyed territory. They are discussed in accordance with the results of laboratory tests (seroepidemiologic and diagnostic) that confirmed the permanent circulation of influenza virus types A(H1N1), A(H3N2) and B in all age groups.

Epidemiologic features of influenza in a large urban centre (B.) in Romania, in 1987.

The study presents the peculiarities of influenza evolution in 1987 in a large town in Romania. These features were defined by a complex methodology, based on clinical, epidemiologic and laboratory investigations, used in the active control of the epidemiologic process kinetics. The influenza viruses type A (H1N1 and H3N2) had a major role in the infecting and immunizing contacts in all age groups whereas the influenza virus type B had a reduced circulation. The epidemiologic influenza impact in 1987 is discussed from the point of view of the complex relationships between the antigenic structure of circulating influenza viruses and the anti-influenza immune profile of the population under the influence of extremely complex economic, social and natural factors.

Epidemiologic particularities of influenza in 1986 in a large urban centre of Romania.

The study presents the evolutive peculiarities of the epidemiologic influenza process in 1986 in a large urban centre in Romania, inferrable from the active control by a complex methodology based on clinical, epidemiologic and laboratory investigations. The prevalent part of A (H1N1 and H3N2) and B influenza viruses in causing seasonal morbidity risings is being stressed. A (H3N2) and B influenza viruses determined an epidemic rising during the first trimester and A (H1N1) and A (H3N2) during the fourth trimester in 1986. The epidemiologic influenza impact in 1986 is discussed from the point of view of the complex relationships between the antigenic structure of circulating influenza viruses and the antiinfluenza immune structure of the population.