EDITORIAL SECTION
EDITORIAL BOARD
R. D. Defries, M.D., D.P.H., Editor
N. E. McKinnon, M.B., and J. T. Phair, M.B., D.P.H., Associate Editors
R. L. Randall, Assistant Editor
A. Marguerite Archibald, M.D., D.P.H. Gordon Bates, M.D. A. E. Berry, M.A.Sc., C.E., Ph.D. J. Craigie, M.B., Ch.B., Ph.D., D.P.H. J. G. Cunningham, B.A., M.B., D.P.H. C. E. Dolman, M.B., B.S., Ph.D., D.P.H., M.R.C.P. D. T. Fraser, M.C.,, B.A., M.B., D.P.H., F.R.S.C. Ronald Hare, M.D. Edna L. Moore, Reg.N. E. W. McHenry, M.A., Ph.D. G. D. Porter, M.B. A. H. Sellers, B.A., M.D., D.P.H. F. O. Wishart, M.A., M.D., D.P.H. J. Wyllie, M.A., M.D., Ch.B., B.Sc., D.P.H.
INFLUENZA
IN the issues of August and this month appear three papers by a team of workers from the Connaught Laboratories, University of Toronto, assisted by physicians in other centres and medical officers attached to Camp Borden Military Hospital. The first paper, published in August, dealt with the serological response of volunteers to a concentrated vaccine made by a method developed in the Connaught Laboratories. There is evidence that the response is at least as good as that during a clinical infection.
This vaccine was made with influenza A virus, and volunteers were immunized in Toronto, Winnipeg, Edmonton, and Vancouver during the months of November and December 1942 and January 1943. An approximately equal number of controls were "immunized" with saline. It was expected that an epidemic of influenza A would make its appearance during the first quarter of 1943 because this variety seems to appear in two-year cycles, the last visitation being late in 1940. A mild epidemic duly made its appearance but its symptomatology was unlike that of influenza A and serological study of the cases showed that about 19 per cent of the cases were probably influenza B. These diagnoses are based on a serological method in which comparison is made between the serum taken during the acute phase of the infection and convalescent serum.
It is true that the actual isolation of the virus from each case should be the logical method of establishing a diagnosis, but the fact that isolation of a virus is at any time surrounded by its own peculiar perils and that influenza B is in this respect even more than usually troublesome, precludes this as a routine method of establishing the diagnosis. For this reason the practice has grown, in recent years, of making a diagnosis on the basis of an increase in the antibody level of the serum during the illness. If the titre increases four times or more, the infection is considered to have been due to the particular virus, influenza A or B, used for the tests. If the titre does not rise to this amount, the assumption is made that these viruses have not been implicated and the infection is considered to have been of unknown aetiology or, as some authors express it, "influenza Y".
While it is possible to accept a positive result by this method without very much hesitation, a negative result is subject to several interpretations. It is [end of text]