PREVENTION OF DIPHTHERIA

Press, Volume LXXXVII, Issue 26517, 4 September 1951, Page 8

PREVENTION OF DIPHTHERIA

TEN YEARS’ SURVEY IN BRITAIN

IMMUNISATION DECLINE NOTED In 1941 50,797 cases of diphtheria were notified in Britain, and of these 2641 were fatal. During 1950 the number of cases had fallen to the provisional figure of 980 with 49 deaths, says a monthly bulletin of the British Ministry of Health in reviewing a survey of 10 years of diphtheria immunisation in Great Britain. The bulletin says that the comparative fatality figures for 1946, 1947, 1948, 1949, and 1950 were 200, 80, 61, 29, and 24 respectively. The case-fatality rate had shoWn no commensurate decline in spite of some lessening in the early years of the immunisation campaign. In 1941 the rate was 5.19 per cent.; in 1950, 5 per cent. The latter figure might have been due to the present rarity of the disease causing - delay in diagnosis and treatment, said the bulletin. The case-fafalitv rate per 1000 persons in 1945 was:—non-immumsed, 68.9; immunised, 8.1: 1946, 62.0—5.5; 1947, 68.6—12.4: 1948. 73.0—7.6: 1949. 66.5—9.2. In 1949 the case-fatality rate for non-immunised children under five years in Britain as a whole was 11.3 per cent., as against 2.3 per cent, for immunised children. In county boroughs the figure for non-immun-ised children from birth to five years was 11.7 per cent., as against 3.2 per cent, for immunised, says the bulletin. Decline in Immunisation In 1950 there was a sharp decline in the number of primary immunisations carried out. The yearly average for 1946-50 was 633.744; 1949, 693,441; 1950, 517,436. ’The total primary Immunisations for the first half-year were 305.529 and 211,907 for the second half year, and this decline is even sharper than the figures suggest, since, in previous years more immunisations have been carried out in the second six months than in the first. It seems to have been caused, to a large extent, by the fear that during times of poliomyelitis epidemics, inoculations may tend to precipitate a paralytic form of that disease.” adds the bulletin. On the other hand, present evidence strongly suggested that the risk of immunisation when poliomyelitis was not rife in a neighbourhood was infinitesimal. The bulletin said that the danger now was that the proportion of protected persons might drop to a level at which not only the population of a few unfortunate towns might fad victims to the disease, but also large parts of the country would be vulnerable. For, whereas vaccination against smallpox became effective in a few days, immunity against diphtheria took several weeks to develop. The only members of a community exposed to diphtheria who could expect protection—at short notice, apart from those receiving the temporary and less dependable protection from therapeutic serum, were those who had been inoculated earlier in life. With the decline in incidence of diphtheria, and the consequent decrease in the number of those who developed immunity through subclinical infection, the significance of inoculation in provicing the means of protection was greatly increased.