09級大5上課件-傳染病學12擇譯

1、1Bacillary dysentery(shigellosis) Department of infectious disease2nd clinical collegeCQMU Dachuan Cai PhD2Introduction:An acute bacterial infection of the intestine characterized by diarrhea, fever, tenesmus里急后重 and in severe cases bloody and mucopurulent stools粘液膿血便.Shigella organisms 志賀菌cause bac

2、illary dysentery, a disease that has been recognized since the time of Hippocrates.3Shigella species are aerobic需氧的, non-motile, glucose-fermenting, non-spore孢子-forming, gram-negative rods. It is highly contagious高感染性的, causing diarrhea after ingestion of as a few as 10 organisms.4 4 species of shig

3、ella are identified, namely: Shigella dysenteriae痢疾桿菌 Shigella Flexneri弗氏志賀菌 Shigella Boydii鮑氏志賀菌 Shigella Sonnei宋內志賀菌5Etiology 67 Virulence in shigella species is determined by chromosomal & plasmid-coded genes質粒基因. VIRULENCE Chromosomal genes control cell wall antigens that are resistant to host d

4、efense mechanisms. Plasmid genes control production of cytotoxin . The cytotoxins are both enterotoxic 腸毒素and neurotoxic神經毒素.8Shigellosis in World9EpidemiologyThe incidence in developing countries is 20 times greater than that in industrialized countries. 95% of shigella infections are asymptomatic

5、hence the actual incidence may be 20 times higher than is reported.10Shigellosis in China111213 monBacteriaintestineNormal bacteria flora & sIg A Prevent attachingPenetrate mucusMultiply in epithelia cell & propria lamina固有層endotoxin內毒素Endogenous pyrogenfeverInflammationvessel contractionSuperficial

6、 mucosal in.nec and ulcerDiarrhea mixed with blood & pus, abdominalache1415transcytosedIntracellular replicationintercellular spreading1617Pathogenesis-toxicStrong - allergy to endotoxinnorepinephrine -adrenalineMicro-circulatory failureShock, DIC, cerebral edema cerebral hernia, MOF18【 PATHOLOGY 】s

7、canty, unformed stools tinged with blood and mucus.Anus19mucosal edemaerythemafriability脆弱superficial ulcers focal mucosal hemorrhageGross pathology:PATHOLOGY20 epithelial cell necrosisgoblet cell depletionpolymorph & mononuclear cell infiltrates in lamina propria crypt abscess隱窩膿腫 formation.Microsc

8、opic pathologyPATHOLOGY2122Clinical Manifestations Bacterialinfecting species /serotypeVirulenceamountHost age Immunologic status nutritional status of the host. 23Basic Clinical Presentations: (1) watery diarrhea associated with vomiting and mild to moderate dehydration(2) dysentery characterized b

9、y a small volume of bloody, mucoid stools, and abdominal pain (cramps腹部絞痛 and tenesmus里急后重) 2425Clinical types:Acute Chronic 26Clinical manifestationAcute dysentery-mild type: caused by S. sonneilow fever or no feverAbdominal pain is mildstool mixed with mucus, without blood & pus27Clinical manifest

10、ationAcute mon type: sudden onset of shiver寒戰(zhàn), high fever,malaise, and anorexia diarrhea:watery diarrhea OR mixed with blood, mucus & pus abdominal pain (tenesmus and cramps) Fecal incontinence大便失禁 may occur.28Clinical manifestationAcute dysentery: -Toxic type: Age: 2 to 7 yrs.Abrupt onset, high fev

11、er, T rise to 40oCListlessness精神萎靡, lethargy昏睡, convulsion驚厥, coma.circulatory & respiratory failurediarrhea mild or absent at beginning 29Major complicationsIntestinal toxic megacolonintestinal perforationsrectal prolapse直腸脫垂Metabolic hypoglycemia hyponatremia dehydration. 30Chronic Dysentery: last

12、 2 monthsAcute attack type: same as common acute dysentery Chronic delayed type: long-time and repeated diarrheaChronic obscure type慢性隱匿性: acute history in 1 year, no symptoms, stool culture or sigmoidscopy Pos. Clinical manifestation31Laboratory FindingsBlood Routine Examination : total WBC:1020%10

13、9/L neutrophils :shift to the leftStool examination: direct microscopic exam.: WBC, RBC, pus cells or macrophage3233343536Laboratory Findings37The gold standard”-stool cultureacute phase of disease freshly passed stool blood-tinged plugs of mucusprompt inoculationRectal swabs直腸拭子 Accredited Technici

14、ansLaboratory Findings38Laboratory Findings39Other methods:PCRSigmoidscopyX-ray:irrigo-radioscopyLaboratory Findings404142Complication bacillus dysenteriae sepsishemolytic uremic syndrome 溶血性尿毒綜合征(HUS)reactive arthritis 反應性關節(jié)炎(Reiters syndrome) 43 DIAGNOSIS 1. epidemiologic data and history 2. clini

15、cal features: symtoms and signs 3. Lab findings : 4445Differential diagnosis Acute dysentery Enteritis caused by E. Coli, salmonella,viral diarrhea Intussusception腸套疊: jelly-like stools果凍狀大便, abdominal mass and absence of fever Amebic dysentery46Toxic symptomseveremilddiarrheaseveremildtenesmusnoted

16、noBacillaryAmebicabdominal tenderness leftright47stoolblood, mucus, and pusjam-like , reddishmicroscopyLeukocytes,erythrocytes Amebic trophozoiteendoscopyhemorrhagic, with mucous discharge and focal ulcerationsflask-shaped ulcer, 燒瓶樣潰瘍48Toxic dysentery (brain form) Japaness B encephalitis a. slowly

17、b. stool c. CFS-IgM d.shock rarelyDifferential diagnosis49Chronic dysenteryRectal & colonic carcinoma: no cure for long-term,drop of weight of body non-specific ulcer colitis: no cure for long-term,culture of stool is negetive, sigmoidoscope:hemorrhage, ulcer,lead pipe.Differential diagnosis50Chroni

18、c schistosomiasis Japonica慢性血吸蟲病 a. contact with the disease-water b. hepatomegaly and splenomegaly c . ova of schistosoma japonicumDifferential diagnosis51Treatment symptom-based and supportive therapy proper rest and diet correction of isotonic dehydrationmetabolic acidosissignificant potassium loss. 52Rice waterORSintravenous fluid replacement Treatment53TreatmentAbdominal crampFeverToxic symptom54Toxic dysentery hyperpyrexia , convulsion