Infective Material The immediate sources of infection are the stools and vomit of carriers. Period of Communicability A case of cholera is infectious for a period of about 7 to 10 days. Convalescent carriers remain infectious for about two to three weeks. Chronic Carriers A chronic carrier state occurs infrequently. Host Factors Age and Sex Cholera affects all ages and people of both sexes. Population Mobility Movement of population (e.g. pilgrimages, marriages, fairs and festivals) results in an increased risk of exposure to the infection. Economic Status The incidence of cholera tends to be the highest in the lower socio–economic groups, and this is attributable mainly to poor hygiene.