No abstract

The results of studies on the age distribution of antibodies, on the range of antibody response to monovalent vaccines by age, and on the age-specific characteristics of antibody demonstrated by serum adsorption tests, have indicated that periods of past prevalence of strains closely related antigenicalIy to swine and Asian strains can be identified. Thus a swine-like virus is thought to have been involved in the pandemic of 1918 and an Asian-fike one in the pandemic of 1889-90.A basic tenet of these serologic recapitulations is that the major antigens of the initial infections of childhood orient antibody formation throughout the rest of life. Upon subsequent exposures to antigenically different yet related strains, the level of the primary antibody is reinforced (1-9).The relevance of this thesis has been questioned by others who take the position that the presence of age-specific antibody patterns cannot be used as a basis for identification of the primary infections because after repeated experiences, minor antigenic components of infecting strains may induce antibody which reacts with the major antigens of viruses to which the subject has not been exposed (10-13). Such an alternate explanation for the serologic findings in humans discounts the fact that titers to other isolates are generally lower than those to the age-specific strains of first infection (1,2,6).It also ignores the temporal association between antibody patterns found in two younger cohorts of the population and the known periods of prevalence of influenza A and influenza A-prime (1, 2), and finally does not consider the fact that with the passage of time the basic antibody reactivity of the respective cohorts persists despite further natural exposures (1, 2, 9).

No abstract

84 forensic necropsy cases with a history of sudden unexpected death and where no acceptable cause of death was found at autopsy (= cases of sudden unexplained death, SUD) were found to have a significantly higher rate of influenza A (H 3 N 2) infection than did matched controls of the general population and a group of forensic necropsy cases with known cause of death (NON-SUD cases). By contrast, the group of SUD cases was found to have no significantly increased infection rate with influenza H 1 N 1 and B virus, parainfluenza viruses, RS virus, adenovirus, and cytomegalovirus. The influenza A associated SUD cases had a significantly higher rate of pathological and histological findings previously described for cases of primary viral pneumonia than did SUD cases without recent influenza A infection and NON-SUD cases. These findings suggest that virological examination of SUD cases could be helpful in order to determine the probable cause of death. A considerable portion of the influenza associated SUD cases occurred during interepidemic influenza periods. Therefore, such cases could be a useful source for monitoring the interepidemic spread of influenza virus.