传染病学教学（重庆医科大学）3yphoid fever.ppt

TYPHOID FEVER AND PARATYPHOID FEVER Tao Peng Associate Professor The Second Affiliated Hospital of Chongqing Medical University Definition of Typhoid fever systemic disease, transmited with digestive tract caused by Salmonella typhi (S.Typhi). prolonged fever, Relative bradycardia, apathetic facial expressions, roseola, splenomegaly, hepatomegaly, leukopenia. intestinal perforation, intestinal hemorrhage Chinese medical expert Zhang ZhongjingShanghan Lun; Treatise on Cold Pathogenic Diseases A.D 200-205 Etiology Serotype: D group of Salmonella Gram-negative rod (antigen O, Vi) flagella (antigen H) endotoxin Endotoxin A variety of plasmids Resistance: Live 2-3 weeks in water. 1-2 months in stool. Die out quickly in summer Resistance to drying and cooling Epidemiology continues to be a global health problem areas with a high incidence include Asia, Africa and Latin America affects about 6000000 people with more than 600000 deaths a year. 80% in Asia . sporadic occur usually, sometimes have epidemic outbreaks. Source of infection Cases and chronic carriersCases discharge from incubation, more in 2~4 weeks after onset, a few (about 2~5%) last longer than 3 months chronic carrier Typhoid Mary Transmission fecal-oral route close contact with patients or carriers contaminated water and food flies and cockroaches. Susceptibility and immunity all people equally susceptible to infection acquired immunity can keep longer, reinfection are rare immunity is not associated with antibody level of “H”, “O”and “VI”. No cross immunity between typhoid and paratyphoid. Susceptibility and immunity All seasons, usually in summer and autumn. Most cases in school-age children and young adults. Man and woman are equally susceptible. 2. Cut of course of transmission key way avoid drinking untreated water and food. hand washing 3.Vaccination side-effect more, less use Pathogenesis gastrointest