The Results of Prophylactic Cholera Inoculation in Faridpur District

During the summer of 1930, a very severe epidemic of cholera broke out in several villages of the Faridpur district, accounting for a total of 3,445 cases amongst a population of only 256,249; of the latter, 52,295 were inoculated at the beginning of the epidemic with one cubic centimetre of cholera vaccine prepared in the Bengal Vaccine Laboratory with local strains. As in some instances a few cases occurred amongst the inoculated also, the whole question was carefully investigated to get an accurate idea of the extent of protection conferred by a single dose of cholera vaccine. The results of such an enquiry are set forth below. The aggregate population of the affected villages is 256,249; of these the inoculated population of 52,295 furnished 171 cases, giving a case incidence of 3.3 per mille, while the uninoculated population of 203,956 gave 3,274 cases, showing a case incidence of 16.0 per mille. As the case incidence varied rather widely in the different areas, it is more satisfactory to take the actual affected units and compare the incidence of the disease in the inoculated and uninoculated populations. (a) In Rajbari thana (population 7,067), 70 per cent, of the population was inoculated. Amongst the inoculated the case incidence was 2.8 per mille and, excluding cases which occurred within five days of inoculation, 1.4 per mille, whilst the case incidence amongst the uninoculated was 90 per mille. The actual figures are very significant. Amongst an inoculated population of 4,946, there were only 14