Mosley, W. H. (Dept. of Population Dynamics, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, Maryland 21205, U.S.A.), Bart, K. J., and Sommer, A. An epidemiological assessment of cholera control programs in rural East Pakistan. Int. J. Epid. 1972,1:5–11. Endemic cholera in rural East Pakistan occurs in annual epidemic waves during the dry season of the year. The cases are widely disseminated; on the average at least 50 per cent of the villages will have one or more cases annually. Endemic cholera is primarily a disease of the young age group, excluding infants, and, in the absence of treatment, contributes significantly to over all mortality. With case rates ranging from 1 to 5 per 1,000 population per year, it can be estimated that rural East Pakistan has from 70,000 to 350,000 cholera cases with 35,000 to 200,000 deaths annually. Because mild diarrheas and inapparent infections occur with such high frequency (4–5 times higher than clinical disease with classical cholera, and 20 to 40 times higher than clinical cases with EI Tor) anti-epidemic measures such as quarantine, isolation, and local disinfection are ineffective in containing the spread of infection. Immunization programs have such low efficacy as to be of no practical public health value. With the present state of knowledge, the most effective measure for cholera control is the establishment of treatment centres as a life-saving measure. These can be as economical as immunization programs, and almost 100 per cent effective. Ultimate control and eradication will come only when a satisfactory vaccine can be developed, or when modern concepts and methods of sanitation can be universally applied in the rural area.