London's Pulse: Medical Officer of Health reports 1848-1972
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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
London County Council 1926
[Report of the Medical Officer of Health for London County Council]
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at the different age periods and the distribution of the disease as regards sex during
the seven years (1919-1925). Non-notified cases are not included in the table.
Age and sex distribution of incidence and mortality (1919-1925.)
| Age periods. | 0-5 | 5-10 | 10-15 | 15-20 | 20-25 | 25-35 | 35-45 | 45-55 | 55-65 | 65-75 | 75 & over | Totals | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | M. | 50 | 63 | 100 | 92 | 56 | 82 | 88 | 77 | 49 | 9 | 6 | 672 |
| 27 | 56 | 56 | 88 | 69 | 86 | 103 | 101 | 42 | 20 | 5 | 653 | ||
| Total | 77 | 119 | 156 | 180 | 125 | 168 | 191 | 178 | 91 | 29 | 11 | 1,325 | |
| Deaths | M. | 24 | 13 | 15 | 26 | 13 | 19 | 42 | 43 | 32 | 7 | 4 | 238 |
| F. | 15 | 16 | 15 | 24 | 16 | 27 | 48 | 53 | 23 | 16 | 4 | 257 | |
| Total | 39 | 29 | 30 | 50 | 29 | 46 | 90 | 96 | 55 | 23 | 8 | 495 | |
| Percentage case-mortality (approx.) | M. | 48 | 21 | 15 | 27 | 23 | 23 | 48 | 56 | 63 | 78 | 67 | 35 |
| F. | 56 | 29 | 26 | 27 | 23 | 31 | 45 | 52 | 55 | 80 | 80 | 39 | |
| Total | 51 | 24 | 19 | 27 | 23 | 27 | 46 | 54 | 59 | 80 | 73 | 37 | |
This is the first occasion on which a table giving a summary of the age and sex
distribution of encephalitis lethargica, both as regards cases and deaths, for the
whole period during which the disease has been notifiable, has been presented in the
annual report. The table is of interest as demonstrating the following points:—
(i) Although encephalitis lethargica is a disease which affects all ages,
it has a definite preference for children and adolescents between the ages of
10 and 20 years, and more especially for those in the age group 15-20 years.
(ii) Whilst there is little appreciable difference in the incidence as between
males and females at all ages, the former being slightly in excess, there is a
preponderance of males over females in the age groups 0-5 and 10-15, although
the mortality is higher among females at these ages. These facts are borne
out by the greater number of applications on behalf of boys suffering from aftereffects
for admission to the Northern Hospital, Winchmore Hill.
(iii) The case mortality rate for the 7-year period was 37 per cent. There
was greater liability to death among children under 5 years of age and among
adults from the age of 35 years, and after this age the death-rate increased
progressively. The lowest mortality occurred in the age period 10-15,
years which comes within the period of highest susceptibility.
In a report on 301 cases of encephalitis lethargica in Sheffield in 1924 recently
issued by the Medical Research Council (Special Report Series No. 108) the following
broad conclusions were drawn:—
1. Statistical estimates of the incidence and fatality of Epidemic Encephabtis
should be accepted with reservation, owing to the occurrence of unrecognised
mild and abortive cases.
2. The evidence already available as to increased susceptibility to infection
in males, and increased liability to death in females is confirmed by the Sheffield
figures.
3. There is an increased susceptibility to infection in males between the
ages of 15 and 30 years.
4. There is no evidence which establishes any relation between the disease
and social conditions, such as overcrowding, poverty or insanitary conditions
in dwellings.
5. There is no evidence of any association with topographical considerations,
or with the supply of water, milk, or any other form of food.