1. Cholera Dept. Infectious Disease Shengjing Hospital CMU

2. Definition  Violent infectious disease of intestinal tract caused by vibrio cholerae  International quarantine  Pathogenic substance: choleragen  Clinical features: profuse diarrhea & vomiting Severe dehydration Muscular cramps Circulatory collapse Renal failure

3. Etiology  Causative organism: vibrio cholerae  G-, short rod, similar to comma  Smear:arrange in shoal of fish  darting movement  Clinical diagnosis  growth on alkaline media

7. Etiology  Pathogenicity- virulence  Choleragen  Endotoxin  enzyme  Resistance: Sensitive to heat, acid, common disinfectants. In river 1-3 weeks, sea food 1-2 weeks

8. Etiology  Antigenicity:  Smatic “ O ” Ag; Flagella Ag: same  Serotype:  O 1 group: A, B, C AB- Ogawa,AC- Inaba, ABC-Hikojima  Atypical O 1 group:Non-pathogenic  Non-O 1 Group: O 2 -O 200 O 139  Biological type:  Classical bio-type- O 1 group  EL-Tor bio-type- O 1 group  O 139- Non-O 1 Group

9. Epidemiology  Source of infection Patients --(mild 18%, asymptomatic infection 75%); Carrier  Route of transmission Fecal-oral route mode of spread: water-borne(outbreak); food-borne(small epidemic); contagious spread  Susceptibility

10. Epidemiology Epidemic features 1. Endemic and exogenous Classical biotype -- six outbreaks Since 1961-- El-Tor biotype which resulted the 7 th outbreak. Since 1992--O 139 biotype which resulted the 8 th outbreak in the world. 2.Periodicity and seasons The peak of epidemic is between July and September summer & fall

11. Bacteria Small intestine Attach to brush border of epithelial cell endotoxinMovement of bowelcholeragen B(binding subunit) A1 + Specific receptor GM1 CELL Adenyl cyclase ATPcAMP Crypt cell:cl - H 2 o HCO 3 Cells of villus:Na + reabsorb Diarrhea, dehydration Pathogenesis

12. Pathology and Pathogenesis  Dominant pathological finding – dehydration  disturbance of electrolyte;  metabolic acidosis

13. Clinical manifestation Incubation period: 1 to 3 days Typical cholera:  Diarrhea & vomiting period:  Diarrhea:100%, rice watery stools with slightly fishy smell;10-20t/d,no pain, no tenesmus, no fever  Vomiting:80%,after onset of diarrhea,no nausea,continuous and effortless.

14. Clinical manifestation  Dehydration period:  Dehydration:  Circulatory collapse: hypovolemic shock  Muscular cramps: loss of Na +,in extremities(calves) and abdominal muscles  Disturbance of electrolyte:  Renal failure: oliguria-anuria- uremia  Convalescent period:  Fever: in 1/3 patients

15. 2 004 年 1 月 27 日一名霍乱患者被送到赞比亚首都卢萨卡的马泰 罗霍乱治疗中心接受治疗

17. Bucket with typical rice-water stool of a patient with cholera

18. Clinical manifestation  Clinical type: according to degree of dehydration,BP,pulse,volume of urine  Mild type  Moderate type  Severe type  Fulminant type – Cholera Sicca

19. Laboratory Findings  Blood picture: hemo-concentration  Urine test: pro. + ~ ++, RBC  Stool test:  Direct observation:darting movement Immobilized test:  Smear: G- arrange in shoal of fish  Culture: alkaline protein media  Serological test: haemagglutination

20. Complications  Acute renal failure:  Acute pulmonary edema:

21. Diagnosis  Epidemiologic data: travelling history; diet history; contact history  Clinical manifestation:  Laboratory findings:  Definite diagnosis:  Symptoms plus culture positive  Epidemiologic investigation, initial stool culture positive, diarrhea before or after 5 days  Epidemic period,typical symptoms but culture is negative, without any other reasons

22. Diagnosis suspected diagnosis:  Typical symptoms and first patient waiting for the result of culture  Epidemic period, contact history (+),diarrhea without any other reasons

23. Differential diagnosis  Acute bacteria gastroenteritis  Viral gastroenteritis  Acute bacillary dysentery

24. Treatment  General treatment:  isolation: when the symptoms disappear,stool cultures are negative for 2 times  Fluid replacement:  Intravenous fluid replacement: kind of fluid:541/321, 5%GNS, 0.9%NS, Ringer ’ volume of fluid: speed of fluid replacement:  Oral fluid replacement therapy:

25. Treatment  adult(ml/d) child(ml/kg.d)  Mild 3000-4000 100-150  Moderate 4000-8000 150-200  Severe 8000-12000 200-250

26. Treatment  Etiological therapy: Antibiotics: deoxycycline for 3 days 1.reduce the duration and volume of diarrhea 2.shorten the period of bacterial excreta from the feces 3.diminish carrier after disease  Symptomatic therapy: eliminate acidosis and hypokalemia correct shock and heart failure

27. Prevention  Control of source of infection:  isolation  International quarantine for 5 days  Interruption of route of transmission  Protection of susceptible population : Vaccinated with cholera vaccine 1.BS-WC 65-85% O1 Classical 2.CVD103-HgR 100% O1 group