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the result that 5,794 children under 5 years of age were done by the Brigade alone. The fact that 82 per cent of the deaths were those of children under 5 years shows the unvaccinated state of the child population.
From the above it will be seen that the St. John's Ambulance Brigade and the Chinese Hospitals and Dispensaries rendered most valuable assistance in the attempt to control the smallpox epidemic by vaccination alone. During 1928 and 1929, 581,921 vaccinations were performed, a total equalling half the population. The constant movement of population into and out of the Colony (some 10,000 per diem) however renders it impossible to maintain a community so immune as to prevent disease spreading when cases are allowed to run their courses in tenement houses and there is no efficient control over the numerous free agents which pass into and out of the premises daily.
After a trial of ten years it would appear to be patent that voluntary vaccination by itself will never efficiently control smallpox, and so long as the present policy prevails so long will Hong Kong remain an endemic centre and year by year be declared infected by other countries.
Plague. Two cases of bubonic plague occurred both being fatal. The first case was reported on the 18th of August and the other on the 2nd of September. Four rats were found plague infected. They came from property adjoining the water front.
Plague has practically disappeared from Hong Kong and the same may be said of most towns in South China. The disappearance in Hong Kong may be and probably is due in some degree to the sanitary measures which have been and are being taken but this cannot be the case in many of the Chinese towns where the conditions are as they have always been. The fact is that the cause of the rise and fall in plague figures has not yet been satisfactorily explained. We know that plague is a disease of rats communicated to man through the medium of the rat flea but we know little of the reason for the rise and fall in the incidence of the disease among rats or what natural causes have an influence on the virulence of the plague bacillus. In spite of the continuous campaign against them there still is and probably always will be a sufficiency of rodents in the Colony to light up and maintain an epidemic.
The cases of Plague recorded in the Colony since the discovery of this disease in 1894 are given in the following table:-
Year Cases Year Cases 1894 5,000 1901 1,651 1895 44 1902 572 1896 1,204 1903 1,415 1897 21 1904 510 1898 1,320 1905 272 1899 1,486 1906 893 1900 1,087 1907 240