Diagnostic Approach to Infective Diarrhoea in the Community and Rational Antibiotic Therapy

1. Diagnostic Approach to Infective Diarrhoea in the Community and Rational Antibiotic Therapy Dr. A. Ayyagari Prof. & Head Department of Microbiology SGPGIMS, Lucknow (U.P.) India Diarrhoea 2003, SGPGIMS, Lucknow

2. Introduction • Major public health problem in India under 5 years. 1/3 of admission and 17% of death) • Definition “passage of loose, liquid or watery stool”. • Acute diarrhoea (GE)- sudden onset which usually last 3-7 days, may 10-14 days. • Non inflammatory e.g. V. cholerae (no abnormal histology) • Inflammatory- with blood and mucus e.g. Shigella Diarrhoea 2003, SGPGIMS, Lucknow

3. Diarrhoea 2003, SGPGIMS, Lucknow

4. Chronic Diarrhoea (>14 days) • Inflammatory- ulcerative colitis, Crohn’s disease, radiation colitis • Osmotic- Whipple’s disease, Celiac sprue, Pancreatic insufficiency • Secretory- Carcinoid syndrome, ZE syndrome, VIP adenomas etc. • Altered motility- IBS, neurologic disease, fecal impaction • Factitious- laxative abuse Diarrhoea 2003, SGPGIMS, Lucknow

5. Cause of Acute diarrhoea (<14 days) • Infectious diarrhoea • Medications • Ischemic colitis • Sup. Mesenteric arterial or venous thrombosis • Acute diverticulitis Diarrhoea 2003, SGPGIMS, Lucknow

6. Infectious diarrhoea- Mechanisms & causes Diarrhoea 2003, SGPGIMS, Lucknow

7. Infectious diarrhoea- Mechanisms & causes Diarrhoea 2003, SGPGIMS, Lucknow

8. Diarrhoea in HIV/AIDS patient Bacteria Virus Parasite C. jejunii CMV Cryptosporidium Shigella sp Enteric adeno Isospora belli Salmonella Calici virus Cyclospora C. difficle HIV Microsporidia EAEC Mycobacterium avium complex Diarrhoea 2003, SGPGIMS, Lucknow

9. Diagnostic approach to Infective Diarrhoea • History Dietary details, travel history, source of drinking water, sexual preferences • Physical examination BP, pulse rate, pulse volume, Abd. Exam, hepatosplenomegaly, lymphadenopathy Diarrhoea 2003, SGPGIMS, Lucknow

10. Lab Diagnosis- Sample collection -collected in acute stage -before the start of the treatment -before the radiological examination -no contamination with urine water or any other infective material -In wide mouthed leak proof screw capped container (25 ml) with a spoon (do not soil the rim of the container) -amount 5 ml of liquid stool/pea size of formed stool -Number – max. 3 samples (2 after normal movement and 1 after cathartic) Diarrhoea 2003, SGPGIMS, Lucknow

11. Lab Diagnosis- Sample Transport • Cary blair transport media (pH 8.4)- Campy., Vibrio • Buffered glycerol transport media (pH 7.0)- Shigella • V.R media (pH 8.6)- V. cholerae • Hank’s balanced salt solution- Virus • Stuart and Amies- general purpose transport media Diarrhoea 2003, SGPGIMS, Lucknow

12. Microscopy Wet mount- Ova and trophozoites of parasites WBCs indicate invasive pathogens Phase contrast microsciopy- Campylobacter Immune electron microscopy- Viruses Staining methods - Oocyst Acis-fast stains- Cold/hot Kinyoun modified stain, Giemsa stain, PAS stain, Direct fluorescence stain, E. histolytica- Trichrome stain Microsporidium- ModifiedTrichrome Gram stain Diarrhoea 2003, SGPGIMS, Lucknow

13. Lab Diagnosis- Enrichment medium Diarrhoea 2003, SGPGIMS, Lucknow

14. Formed/semiformed stool (1:10 dilution in 2-3 ml PBS or 0.1% peptone water)  Liquid stool (Cholera suspected by characteristic Motility and immobilisation by specific sera)    Grams stain if required MacConkey Selenite F broth  XLD/DCA GN broth Typical morphology DSRA  Further processing Subculture on of DCA/MAC Pure LF cononies within 6 hour All NLF col(oxidase negative) on MacConkey, should be S/c on DCA All black centered colony on DCA All non sorbitol fermenter colony (EHEC) Diarrhoea 2003, SGPGIMS, Lucknow

15. Classification of Enteropathogenic E. coli Diarrhoea 2003, SGPGIMS, Lucknow

16. Antibiotic Associated Diarrhea • Most common cause of diarrhea among hospitalized patients (Range-1 in 10 to 1 in 10000) • 3-5 billion annual infection annually, 3 million deaths/ year. • 1.5 episodes per person/ year > 50% death: elderly • Self limiting, ~ 50% within 3 days. Diarrhoea 2003, SGPGIMS, Lucknow

17. Antibiotics implicated in AAD • Frequently: Ampicillin, Amoxicillin-clavulenate, 2nd & 3rd generation Cephalosporin, Clindamycin • Uncommon: Tetracycline, sulfonamides, Quinalone, Erythromycin, Chloramphenicol, TMP, • Antineoplastic agents > Methotrexate, Other agents (Anon, 1993)- Dexorubin, cyclophosphamide • Tube feeding- Nosocomial CD collitis. Diarrhoea 2003, SGPGIMS, Lucknow

18. Lab Diagnosis of AAD • Specimen- Stool (fresh sample), colonic biopsy • Non specific-  leucocytes in stool in AAD & PMC • Colonoscopy/ sigmoidoscopy (erythema, edema, friability, adhered yellow plaques) in PMC. Endoscopy ? Normal in mild cases • Radiographic imaging • Surveillance of nosocomial infection- • Swab from inanimate surroundings & hospital personnel Diarrhoea 2003, SGPGIMS, Lucknow

19. Stool Tests for C. difficile Infection Diarrhoea 2003, SGPGIMS, Lucknow

20. Viruses causing Acute Gastroenteritis Other viruses- Torovirus [ss(+)RNA], Picovirna virus [dsRNA], Enterovirus 22 [ss(+)RNA], Aichi virus [ss(+)RNA Diarrhoea 2003, SGPGIMS, Lucknow

21. Diagnosis of Viral diarrhoea Non Rota- • Direct and immune Em • Antigen detection- EIA with hyper immune sera , EIA with monoclonal antibody • Antibody detection • Culture • Hybridization probes- for adeno viruses • RT-PCR for HuCV Rota- EIA, membrane EIA, LA, EM, culture, RT-PCR Diarrhoea 2003, SGPGIMS, Lucknow

22. Rational Antibiotic Therapy Most cases are self limiting and subside with supportive therapy Indication of antibiotic therapy • Cholera • Febrile bloody diarrhoea • Travelers diarrhoea • extremes of age • Food handlers • Immunocompromised • Day care attendee • Residents of institutional facility • Epidemic outbreaks Diarrhoea 2003, SGPGIMS, Lucknow

23. Rational Antibiotic Therapy Problems of empiric therapy- • Not effective in EHEC, salmonella enterocolitis • In children- most cases are viral • Emerging drug resistance • Side effects • Alteration of gut flora • Induction of disease producing phage e.g; Shigatoxin phage induced by quinolones Diarrhoea 2003, SGPGIMS, Lucknow

24. Therapeutic recomendations • Shigella- TMP-SMZ, Cipro, Norflox • Salmonella-Quinolones, Ceftrixone • V.cholerae - Doxycycline, Tetracycline, Erythromycin • E. coli-Cipro, norflox • C. difficile-Metronidazole, Vanco • Cryptosporidium- Paromomycin • Isospora- TMP-SMZ, • Cyclospora-TMP-SMZ Diarrhoea 2003, SGPGIMS, Lucknow

25. Control measures WHO, UNICEF- oral rehydration therapy. Short-term: (a) ORT – 1978 started in 85-86 (National program), 92-93 (included in maternal and child health program) (b) normal food intake, breast fed (c)Chemotherapy- Infective; Cholera Toxins; Shigella, E. coli, Campylobacter Invasive; Salmonella Diarrhoea 2003, SGPGIMS, Lucknow

26. Control measures Long-term: • Nutrition • Sanitation- to stop the transmission Oro-Faecal Water supply Food • Health education- environment, clean drinking water • Immunization • Fly control Diarrhoea 2003, SGPGIMS, Lucknow

27. Vibrio cholerae on TCBS Diarrhoea 2003, SGPGIMS, Lucknow

28. Salmonella on XLD Diarrhoea 2003, SGPGIMS, Lucknow

29. Cryptosporidium parvum in stool(Modified acid fast) Diarrhoea 2003, SGPGIMS, Lucknow

30. Isospora belli-Direct smear(Kinyoun stain) Diarrhoea 2003, SGPGIMS, Lucknow

31. Cyclospora cayetanensis-oocyst (modified acid fast) Diarrhoea 2003, SGPGIMS, Lucknow

32. Microsporidian spores(Modified Trichrome blue stain) Diarrhoea 2003, SGPGIMS, Lucknow

33. Clostridium difficile growth under UV light Diarrhoea 2003, SGPGIMS, Lucknow