<prompt> Case fatality rate of typhoid is -10203040  <response>: Typhoid fever:- Typical continuous fever for 3-4 weeks,relative bradycardia with involvement of lymphoid tissue. Without effective treatment, typhoid kills over 10 of those infected. Causative agent- Salmonella typhi. S.paraA and S.paraB are infrequent. Reservoir- man Case - a case is infectious as long as bacilli appear in stools urine. Carriers:- 1. Convalescent carriers-excrete bacilli for 6-8 weeks,after which their number dimnishes rapidly. 2. Chronic carriers- persons who excrete bacilli for more than a year after a clinical attack. In most chronic carriers,the organism persists in gall bladder and in biliary tract. Source of infection- faeces and urine of casescarriers. Age group involved mostly is 5-19 yrs old. Males affected more than females. Incubation period- 10-14 days. Mode of transmission: faecal oral route urine oral routes. Treatment of carriers:- Intensive course of ampicillin amoxycillin 4-6gday together with probenecid for 6 weeks. Reference: park;s textbook of preventive and social medicine, 23rd edition, pg no.235 