SEROEPIDEMIOLOGIC SURVEY OF INFLUENZA-C VIRUS-INFECTION IN SPAIN

From an overall point of view, the epidemiological situation of influe nza C virus infections in western Europe is hardly known. In some coun tries like Spain, no epidemiological survey has been carried out to de termine whether influenza C virus does or does not circulate and cause infection in the considered geographical area. We thus decided to per form such a study. A total of 191 serum samples was collected from peo ple (from 1.5 to 80 years old) living in Spain in October 1990. These sera were tested for the presence of antibodies to influenza C virus b y hemagglutination-inhibition (HI) tests. Significant HI activity was found in 59.3 to 64.9% of the 191 tested sera and titres ranged from 2 0 to 320. The high prevalence of antibody as well as the highly signif icant titres indicate an intense circulation of influenza C virus in S pain. A significant difference was found between children/teenagers an d adults.