Skip to main content

The role of season in the epidemiology of influenza

  • R. E. Hope-Simpson (a1)

Four types of observations have been used to illustrate the seasonal characteristics of epidemic influenza: (1) The experience of a small population during 28 consecutive years, 1946–74, (2) world influenza outbreaks 1964–75 reported to the World Health Organization, (3) the experience of two widely separated localities at about the same latitude, 1969–74, and (4) the experience of two places at latitudes 30° + on opposite sides of the Equator, 1968–74.

The following tendencies are shown. (1) Outbreaks of influenza even in the small community came at approximately the same season almost every year. (2) Outbreaks are globally ubiquitous and epidemic loci move smoothly to and fro across the surface of the earth almost every year in a sinuous curve that runs parallel with the ‘midsummer’ curve of vertical solar radiation, but lags about six months behind it. Such findings exclude the mediation of seasonal control by any agencies of local distribution, and suggest a direct effect of variations in some component of solar radiation on virus or human host. (3) Antigenic variations in influenza A virus tended to have the same seasonal characteristics as epidemicity. This suggests that epidemicity and virus variation are two facets of one seasonally controlled process.

None of these seasonal characteristics can be explained by the current concept of influenzal epidemiology. A new hypothesis recently proposed and recapitulated in the Appendix offers a possible explanation. The primary agency mediating seasonal control remains unidentified.

Hide All
Archetti I. & Horsfall F. L. (1950). Persistent antigenic variation of influenza A virus after incomplete neutralisation in ova with heterologous immune serum. Journal of Experimental Medicine 92, 441–52.
Fothergill J. (1784). A sketch of the epidemic disease which appeared in London towards the end of the year 1775. In The Works of John Fothergill, London (ed. Lettson J. C.), III, pp. 251302.
Gill P. & Murphy A. M. (1976). Naturally acquired immunity to influenza type A. A clinical and laboratory study. Medical Journal of Australia 2, 329–33.
Hope-Simpson R. E. (1958). The epidemiology of non-infectious diseases. a. Common upper respiratory diseases. Royal Society of Health Journal 78, 593–9.
Hope-Simpson R. E. (1979). Epidemic mechanisms of type A influenza. Journal of Hygiene 83, 1126.
Kilbourne E. D. (1975). The Influenza Viruses and Influenza, 508 pp. New York: Academic Press.
Shadrin A. S., Marinich E. G. & Taros L. Y. (1977). Experimental and epidemiological estimation of seasonal and climato-geographical features of non-specific resistance of the organism to influenza. Journal of Hygiene, Epidemiology, Microbiology & Immunology 21, 156–61.
Strnad P., Tumova B., Syrucek L., Fedova D., Bruckova M., Kunzowa L., Stumpa A., Strizova V., Berkovicova V. & Losova M. (1976). Influenza and other acute respiratory diseases in the Czech Socialist Republic, 1969–74. Bulletin of the World Health Organization 54, 657–62.
Tromp S. W. & Bouma J. J. (eds) (1979). Biometeorological Survey 1979. 1A. Human Biometeorology. 1B. Animal Biometeorology. London: Heyden & Sons. (Both parts contain relevant reviews with useful references.)
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
  • URL: /core/journals/epidemiology-and-infection
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 12 *
Loading metrics...

Abstract views

Total abstract views: 141 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 18th January 2018. This data will be updated every 24 hours.