<prompt> The infectivity of a convalescent case of cholera lasts forLess than 7 days7-14 days14-21 days21-28 days  <response>: Preclinical or incubatory carrier -The incubatory carriers are potent carriers 1-5 daysConvalescent carrier - Patient who has recovered from an attack of cholera may continue to excrete vibrios, during his convalescence for 2 -3 weeksContact or healthy carrier - Subclinical infection contracted through association with a source of infection. Duration 10 days.Chronic carrier - Over 10 yearsRefer: K. Parks Textbook of Preventive and Social medicine, 24thedition, pg no: 244 