医学精品课件：05.Yuzebo.Bacillary dysentery.ppt

1、Bacillary dysentery ShigellosisInfectious diarrheaYu Zebo2023-1-17Shigellosis2nPatient xxx,female,25-year-old,nursemaid,Suddenly onset 2 days ago with general malaise,chill,fever,fatigue,headache and cramping abdominal pain,especially in left inferior abdomen,then followed diarrhea with water stool

2、initially,and then bloody purulent stools,1020 times per day,accompanied with burning sensation at Anus-tenesmus.Five days ago this woman had nursed a diarrhea patient.Case reportTerm explanation：Tenesmus is the constant feeling of the need to pass stool,accompanied by pain,cramping because of infla

3、mmatory of the bowel,but little stool is passed.2023-1-17Shigellosis3nPE：T 39.5，R 30/m，P 110/m，BP 110/80mmHg。Press-pain on the left inferior abdomennBlood test:WBC 12.5109/L;neutrophilic leukocyte 85%。Stool test:WBC 5060/HP，RBC2030/HP。Questionsn1.What disease is the patient suffered from?n2.What is

4、the principle of treatment for this patient?n3.How to prevent this disease?2023-1-17Shigellosis4Contents nGeneral conditionnEtiologynEpidemiologynPathogenesisnClinical manifestation nLaboratory examinationnDiagnosis (Epidemic data,symptoms,signs,laboratory findings）nDifferential diagnosisnTreatmentn

5、PreventionIts specific features that there are microorganisms for infectious diseases chemical factorsphysic factors No microorganisms2023-1-17Shigellosis51.General conditionnDefinition:Shigellosis is also called bacillary dysentery,this is an acute bacterial disease characterized by fever,nausea,vo

6、miting,cramps,diarrhea and feeling of tenesmus caused by Shigella species.In most cases,the stools contain blood and mucus.Tenesmus is the constant feeling of the need to pass stool,accompanied by pain,cramping because of inflammatory of the bowel,but little stool is passed.2023-1-17Shigellosis6n Ty

7、pical clinical featuresnShigella is transmitted directly or indirectly via the fecal-oral route and may occur due to the ingestion of contaminated food or water.nWhole body symptoms:fever and toxemia(chill,fatigue,headache)nLocal symptoms:diarrhea,bloody purulent stools,abdominal pain,tenesmus.nSign

8、s:Press-pain on the left inferior abdomen.Laboratory findings:Blood test:WBC ,neutrophil Stool test:WBC ,RBC 2023-1-17Shigellosis72.EtiologynShigella:nGram-,facultative anaerobic(with or without oxygen),rod bacterianVery similar to E.colinpH:survives in neutral pH,resistant to stomach acidsnTemperat

9、ure:(depends on serotype.)nCan survive at 4C for 21 days in cheese,potato,salad and mayonnaisenCan survive and grow at under 25 C for 50 days in flour,milk,eggs,shrimps,oysters2023-1-17Shigellosis8Etiology4 serogroups:nA:S.dysenteriaenMost severe “Bacillary dysentery”;developing countries in Africa,

10、Latin America,AsianB:S.flexnerinMost common Shigella in developing countries;nbecoming more common in developed countriesnC:S.boydiinD:S.sonneinLeast severe;developed countriesn(In china:B and D)2023-1-17Shigellosis925ShigellaShigella sonneisonnei2023-1-17Shigellosis10Shigella bacteria in a stool sa

11、mple(Under high power microscope)2023-1-17Shigellosis11Gram stain:Shigella2023-1-17Shigellosis12Several media have been designed to selectively grow enteric bacteria and allow differentiation of Salmonella and Shigella from E.coli.The primary plating media shown here are eosin methylene blue(EMB)aga

12、r,MacConkey agar,ENDO agar,Hektoen enteric(HE)agar and Salmonella-Shigella(SS)agar.2023-1-17Shigellosis133.EpidemiologynWorldwide,major cause of diarrhean(165 million cases/year 99%in developing c.)nIs about 5-15%of all cases of diarrhea,mostly kids 1020109/LnStool test:Bloody purulent appearance.Le

13、ukocytes can be found 15/HPnBacteria culture:(+),the dysentery bacillus of the culture is a golden standard of disease diagnosis.nEarly,frequently,freshly collect sample(inoculated culture)-can improve culture positive rate.nBlood culture:unnecessary!(most of the bacteria do not invade into the bloo

14、d!)2023-1-17Shigellosis31Shigellosis:Possible complicationsnIntestinal perforation:Rarely occursnSepticemia:usually caused by B serogroups(S.flexneri)nReactive Arthritis-Reiters syndrome n(after 2 weeks of Shigellosis)nSeveral joints are usually affected especially the knees.nIt also occurs after ge

15、nital tract infection(such as gonorrhea)nHUS:Hemolytic Uremic Syndrome(caused by S.dysenteriae or EHEC-enterohemorrhagic E.coli O157)n hemolytic anemia,and acute renal failure.2023-1-17Shigellosis327.DiagnosisnEpidemic data(exposed to patients)nClinical feature(typical type)nLaboratory findingsnAimi

16、ng to toxic dysentery,checking stools by digital rectal examination(DRE)or cold salt liquid enema is the most important diagnosis method.2023-1-17Shigellosis338.Differential diagnosisnAcute dysentery:Amebic dysentery(see below table)nChronic dysentery:colitis,corndisease,tumornDepend on colon endosc

17、ope and biopsynToxic dysentery:encephalitis(such as encephalitis B)nThe onset of toxic dysentery is more quickly than encephalitis B.nToxic dysentery is accompanied with circulation failure or shock.nchecking stools by cold salt liquid enema can provide valuable clue.2023-1-17Shigellosis34amebic dys

18、enteryShigellosis General conditionmild，lower fever,toxemia unusually severe,high fever,toxemia usually Stool frequencyless,210 times/daymore,1030 times/dayStool volumeMore/each time Less/each time Tenesmusmild or withoutObviously Site of press-pain right inferior abdomenleft inferior abdomenStool a

19、ppearancemore fecal and less watery,contain mucus,like fruit paste with uncomfortable odors less fecal,contain purulent and blood,without special odorsStool under microscopeFewer WBC,More RBC,Special crystal More WBC,Fewer RBCStool cultureWithout Shigella Shigellatreatment metronidazoleFluoroquinolo

20、nes or 3rd cephalosporin(cefotaxime)2023-1-17Shigellosis359.Treatment Acute dysenterynAntibiotics medication is very important.nTo severe cases,treatment with antibiotics can shorten the duration of the illness.and can reduce the period of excretion of the organism.nTo mild cases,treatment with anti

21、biotics is unnecessary.2023-1-17Shigellosis36Selection of antibiotics nThe first line medication should be quinolones,such as norfloxacin(0.4 tid for adult)or Ciprofloxacin(0.2 tid for adult)or Ofloxacin(0.2 tid for adult).The duration is 35 days for typical cases.nFor severe cases,Quinolone or 3rd

22、cephalosporin,such as Ceftriaxone or cefotaxime were chosen with vein route.nBecause of high drug-resistance and unsafety,sulphonamides or chloramphenicol were not recommended 2023-1-17Shigellosis37Rehydration TreatmentnAlthough dehydration is not a common feature of shigellosis infection,but if it

23、occurs or the stools are watery,patients should be given the oral rehydration salt(ORS)recommended by WHO/UNICEF(United Nations International Childrens Emergency Fund)nIn severe dehydration,intravenous fluids is recommendednHowever,clinical experience indicates that ORS is beneficial in all cases of

24、 shigellosis if given as routine fluid intake.2023-1-17Shigellosis38Nurses is encouraging patient to drink an ORS(Oral Rehydration Solution)to improve dehydration2023-1-17Shigellosis39Symptomatic treatmentnAbdomen pain:atropine 0.5mg,ImnHigh fever or toxemia:dexamethasone(DXM)nShock:nHigh effect and

25、 broad spectrum antibiotics nSupply enough fluid intravenouslynDrugs that constrict the blood vessels may be given to boost blood flow to the brain or heart(dopamine,1020 g/kg/min)nGlucocorticoid(such as DXM to reduce symptom of toxemia)2023-1-17Shigellosis40Toxic bacillary dysenterynAntibiotics adm

26、inister intravascularlynAnti-shocknPrevent and cure hydrocephalusnDehydration with 20%mannitol 125ml-250ml,q412h nInhale oxygen nKeep respiratory function normal.2023-1-17Shigellosis4110.Shigellosis:Preventionn1.Control the source of infection.Individuals excreting shigellae should be isolated early

27、 until negative cultures have been obtained from the stool specimens.(Carriers!ignore)n2.Cutting out the rout of transmission.nAll individuals exposed to patients of shigellosis should wash hand with soap and water.nEspecially food handlersn3.Vaccination?nNO vaccine available in clinic up to now.202

28、3-1-17Shigellosis42nPatient xxx,female,25-year-old,nursemaid,Suddenly onset 2 days ago with general malaise,chill,fever,fatigue,headache and cramping abdominal pain,especially in left inferior abdomen,then followed diarrhea with water stool initially,and then bloody purulent stools,1020 times per da

29、y,accompanied with burning sensation at Anus-tenesmus.Five days ago this woman had nursed a diarrhea patient.nPE：T 39.5，R 30/m，P 110/m，BP 110/80mmHg。Press-pain on the left inferior abdomenReview the Case report2023-1-17Shigellosis43nBlood test:WBC 12.5109/L;neutrophilic leukocyte 85%Stool test:WBC 5060/HP，RBC2030/HP。Questionsn1.What disease is the patient suffered from?n2.What is the principle of treatment for this patient?(Antibiotics and symptomatic,supportive treatment)n3.How to prevent this disease?(isolate the patient and washing hands)2023-1-17Shigellosis44