The role of some viruses in acute pneumonias in adults.

Virological and bacteriological investigations were performed in 85 patients with acute pneumonias and virus isolation or serological evidence of virus infection were obtained in 37.6% of the cases. Influenza A2 and B viruses were incriminated in 14.1% of the patients; parainfluenza viruses in 7% and adenoviruses in 17.2% of the cases. Coxsackie virus was isolated from one patient's blood, and poliovirus 3 was recovered in 3 cases. In 5 cases associated virus infections were detected.

[Some respiratory viruses in the etiology of acute upper respiratory infections]. / Unele virusuri respiratorii în etiologia afectiunilor respiratorii acute superioare

The viral etiology of acute respiratory diseases, determined in 107 children admitted to hospital during the 1966-1969 period, was confirmed in 36% of the cases by isolation of the viral agent and in 59% by serologic reactions. Parainfluenza viruses, especially of type 1 and 3, were encountered more often in the etiology of acute or obstructive laryngitis, and the syncytial respiratory virus in tracheobronchitis.

Importance of associated viral and bacterial infections in the production of acute pneumonias.

Bacteriologic and virologic investigations carried out in a group of 85 patients with acute pneumonia have allowed the determination of the etiologic agent in 52.9% of the cases. Of these, 40% showed combined viral and bacterial infections. Mixovirus infections were frequently associated with staphylococcic ones (7 out of 8 cases) and adenovirus infections with the pneumococcic ones (6 out of 7 cases). The most severe and longdrawn clinical pictures with frequent pleuropulmonary complications (in 22.24% of the cases) had a biphasic evolution in only 6 of the 18 pneumonias of mixed etiology. For their high frequency and their clinical peculiarities, mixed etiology pneumonias might be considered as distinct clinical entities.

Importance of associated viral and bacterial infections in the production of acute pneumonias.

Bacteriologic and virologic investigations carried out in a group of 85 patients with acute pneumonia have allowed the determination of the etiologic agent in 52.9% of the cases. Of these, 40% showed combined viral and bacterial infections. Mixovirus infections were frequently associated with staphylococcic ones (7 out of 8 cases) and adenovirus infections with the pneumococcic ones (6 out of 7 cases). The most severe and longdrawn clinical pictures with frequent pleuropulmonary complications (in 22.24% of the cases) had a biphasic evolution in only 6 of the 18 pneumonias of mixed etiology. For their high frequency and their clinical peculiarities, mixed etiology pneumonias might be considered as distinct clinical entities.

[Vaccination strategy in influenza]. / Strategia vaccinarii în gripa

The present paper deals with the conditions that influenza vaccines must comply with, their efficiency in terms of the route of administration, the major antigenic changes of influenza viruses, that has to be known from beforehand, a basic problem for the efficient control of a pandemic. Vaccination must have in view reduction of the mortality and morbidity rate, a major criterion in establishing a programme for the prevention of influenza by vaccination.

[Characteristics of immunity in influenza]. / Particularitatile imunitatii în gripa

Immunity in influenza is a complex phenomenon that depends upon numerous factors whose importance is not yet sufficiently known. The following mechanisms of defence are triggered by infection with the influenza virus: (a) The immune secretory system: -- IgA antibodies, --immune response in terms of the vaccinating dose, previous immunologic experience and time (appraised according to the moment in which infection started). (b) Serum antibodies: -- to the soluble antigen, -- to surface particulate antigens (hemagglutinin and neuraminidase), --antihemagglutinin and antineuraminidase antibodies, indicating the degree of protection. (c) Cellular immunity: -- influenza virus inducing the proliferation of lymphocytes in vitro and activating the inhibitory factor of mononuclear migration, -- mediated immunity. These problems of immunity have not yet been fully elucidated.

[Supplementary data on the theory concerning the cyclic evolution of influenza viruses]. / Date suplimentare in favoarea ipotezei privind evolutia cicica a virusurilor gripale

The distribution per age groups of antibodies to influenza viruses A/Hong Kong/1/68, A/England/837/69 and A/England/42/72 in the sera collected in 1970 demonstrates that antigenically similar strains also dominated the epidemiologic picture of influenza in the past century. The results suggest that the pandemic of 1893 and infection in persons born before 1885 were caused by a strain similar to A/Hong Kong/1/68 and in those born in 1895-1897 by the antigenic variant A/England/42/72. The anamnestic response to the A/England/69 variant, following upon vaccination with the Hong Kong strain shows that the primary infection in persons born before 1900 was caused by a strain antigenically similar to the first variant. The data obtained lend support to the hypothesis of antigenic recycling of influenza virus and of the finite character of the antigenic variation of influenza viruses.