1. INTESTINAL INFECTIONS
MUDr. RNDr. František Stejskal, Ph.D.
November 19, 2007
Department of Tropical Medicine
1st Faculty of Medicine
Charles University
and Hospital Bulovka
Studničkova 7, Praha 2

2. DIARRHEA - DEFINITION DIARRHEA ACUTE DIARRHEA
Increase in fluidity, volume or frequency of bowel movement
Normal bowel habit varies greatly from person to person
Above 12 mo age, more than 3 loose stools per day are abnormal
ACUTE DIARRHEA
Subside spontaneously within a few days
PERSISTENT AND CHRONIC DIARRHEA
Persist for more than 2 – 3 weeks

3. TERMINOLOGY OF DIARRHEAL DISEASES
Symptoms/signs
Example/etiology
Gastritis
Vomiting, nausea, no fever
Food poisoning, preformed toxins (Staphylococcus aureus, Bacillus cereus)
Gastroenteritis
Vomiting, nausea, diarrhea usually watery without blood, abdominal pain/cramps, fever may be present
Food poisoning, preformed toxins
Cholera
Salmonellosis, giardiasis
Enteritis
No vomiting
Salmonellosis, giardiasis, cryptosporidiosis
Enterocolitis
No vomiting, diarrhea often with blood, abdominal pain/cramps
Campylobacter, Yersinia enterocolitica
Colitis
- ulcerative
- pseudomembranose
Diarrhea with blood and pus, abdominal cramps, tenesm, fever may be present
Bacillary, amoebic dysentery
Intestinal schistosomiasis
Ulcerative colitis
Bloody diarrhea, abdominal cramps, usually without fever
Clostridium perfringens C (pigbel), Cl. difficile

4. INFECTIVE DIARRHEA VIRUSES Rotaviruses Norwalk virus (Noroviruses)
Caliciviruses
Astroviruses
Enteric adenoviruses

5. INFECTIVE DIARRHEA - BACTERIA
Enterotoxicoses (preformed toxin)
Bacillus cereus
Staphylococcus aureus
Clostridium perfringens C
Cholera and other Vibria
Enterotoxigenic E. coli (ETEC)
Salmonellosis
Campylobacter jejuni
Yersinia enterocolitica
Shigellosis
Enteroinvasive (EIEC) and enteroadherent E. coli
Aeromonas hydrophila
Plesiomonas shigelloides

6. INFECTIVE DIARRHEA - PARASITES
Protozoa
Giardiasis
Amebiasis
Cryptosporidium
Cyclospora
Isospora
Helminths
Ascariasis
Trichuriasis
Ancylostomosis
Strongyloidosis
Taeniasis

7. PATHOGENESIS OF INFECTIVE DIARRHEA
Toxin production
Staphylococcus pyogenes, St. aureus (preformed toxin)
Vibrio cholerae, ETEC toxin (↑cAMP – inhibition of Na+ absorption)
Enterocytes adhesion and colonisation
E.coli
Giardia intestinalis
Destruction of intestinal mucous membrane at the bacterial or parasite attachment place
Enteropathogenic E. coli, viruses
Cryptosporidium
Mucous membrane and submucose invasion
Salmonella, Campylobacter jejuni, Yersinia enterocolitica
Isospora, Cyclospora
Colonic wall invasion and ulcers formation
Shigella, enteroinvasive E.coli (EIEC)
Entamoeba histolytica

8. PATHOGENESIS OF DIARRHEA II
Host defense mechanism:
Increased risc:
- Treatment with anacides, proton pump inhibitors, H2 inhibitors
- Immunity defects – IgA deficiency
Infective dose:
Low (less than 103 bacteria cells)
- shigellosis, Campylobacter (contagious infections)
High (more than 103 bacteria cells)
- salmonellosis

9. SOURCE OF INFECTION EPIDEMIOLOGY
Contaminated water
Undercoched or roh meat, fish or seafood
Fruits and vegetabele
Milk products

10. ACUTE DIARRHEA – DIFFERENTIAL DIAGNOSIS
With fever and with blood
Shigellosis, Campylobacter, EIEC, Cl. perfringens C – enteritis necroticans, (salmonellosis - 50%, typhoid)
With fever and without blood
Rotaviruses, Norwalk, salmonellosis (50 %); any localized infection at small children (otitis, tonsillitis, pneumonia), malaria
Without fever and with blood
Amoebiasis, intestinal schistosomiasis, balantidiosis, trichuriasis
Without fever and without blood
cholera, ETEC, enterotoxicosis (stafylococcal, B. cereus), cryptosporidiosis, isosporiasis, cyclosporiasis

11. CHRONIC DIARRHEA With fever Without fever and with blood
Intestinal tuberculosis, visceral leishmaniasis, yersiniosis, HIV infection, CMV
Without fever and with blood
Amoebiasis, intestinal schistosomiasis, balantidiosis, trichuriasis, Crohn disease, idiopatic proctocolitis
Without fever and without blood
Giardiasis, tropical sprue, coeliacal sprue, lactase deficiency, strongyloidosis, cryptosporidiosis, Whipple disease, intestinal malignant lymphoma, mucoviscidosis

12. INVESTIGATION IN DIARRHEA
Fecal smear: fecal leucocytes
Stool culture
Parasitic stool investigation (persistant diarrhea, for more than 2-3 weeks)

13. DIRECT FAECAL SMEAR
Place a drop of sterile saline on the left hand site of the slide; place a drop of iodine on the right hand site of the slide and add a small portion of stool to each drop and mix to form suspension
Cover with a coverslip and examine with the x10 objective first
Mr. Brown
X 10/12/04

14. White blood cells (WBC)
FECAL LEUCOCYTES
Mucus (pus) from stool is stained with 2 drops of Lőffler’s methylen blue
Infection/disease
White blood cells (WBC)
Viral gastroenteritis NO
Cholera, ETEC, enterotoxicosis
Giardia, Cryptosporidium
Salmonella typhi
Monocytes
Salmonellosis (S. enteritidis)
PMN
Shigellosis, EIEC
Campylobacter, Yersinia enterocolitica
Entamoeba histolytica, Balantidium coli
Ulcerative colitis, Crohn disease

15. DIRECT FAECAL SMEAR - RESULTS
Cysts (Giardia, amoebas, etc.)
Trophozoites (amoebas, Giardia, trichomonads, other flagellates, etc)
Oocysts (Isospora, Cyclospora) of parasitic protists
Blastocystis hominis
Yeasts (Candida, Saccharomyces)
Ova of parasitic helmints
Vibrio cholerae
Negative in cryptosporidiosis, special staining

16. STOOL CULTURE
Routine: Salmonella sp., Shigella, Citrobacter, Proteus sp., Morganella sp. and other enterobacteria
Special: Campylobacter, Vibrio cholerae, Yersinia enterocolitica
Yeasts
Virus isolation (enteroviruses)
Parasites – special culture media:
Amoebas, trichomonads, other flagellates

17. THERAPY OF DIARRHEA

18. ORAL REHYDRATATION SOLUTION
NaCl 3,5 g
KCl 1,5 g
Na-bicarbonate 2,5 g or Na-citrate 2,9 g
glucose 20 g or saccharose 40 g
in 1 L of boiled water
Add 1 tsp of salt and 2-3 tsp of sugar or honey and 1 lemon to 1 liter of water.

19. ORS WITH REDUCED OSMOLARITY
ORS solution does not reduce stool output or duration of diarrhoea
This solution, which is slightly hyperosmolar when compared with plasma, may cause hypernatraemia or an osmotically driven increase in stool output, especially in infants and young children
For this reason paediatricians in some developed countries recommended the ORS with reduced osmalarity containing about 60 mEq/l sodium and having a total osmolarity of 250 mOsm/l

20. COMPARISON OF ORS and Valík solution
Original ORS g/L
Valík solution g/L
NaCl
3,5
2,36
KCl
1,5
1,12
Na-bicarbonate
2,5
1,68
Glucose 20
27,0

21. ORS WITH REDUCED OSMOLARITY
Na+: mEq/l (original ORS 90 mEq/l)
Glucose: mmol/l
Total osmolarity: mOsm/l (original ORS 311 mOsm/l)

22. USE OF ANTIMICROBIAL DRUGS
Bloody diarrhea with fever (dysentery) which does not improve after 2-3 days or rehydratation
Cholera with severe dehydratation
Bacterial diarrhea at immunocompromised patients
Diarrhea with high fever in small children
Parasitic diarrhea

24. CHOLERA

25. Seventh pandemic of cholera, 1961-1971 (CDC)
CHOLERA PANDEMIC
Seventh pandemic of cholera, (CDC)

26. CHOLERA Humans are the only known natural host
Large infective dose – contaminated food or water
Incubation period: a few hours to 5 days
Severe watery diarrhea (up to 30 L per day), painless, without fever
Electrolyte imbalances, metabolic acidosis, prostration, dehydration
Management: ORS, doxycyclin 300 mg in single dose in the severe cases

27. DIAGNOSIS OF CHOLERA In epidemics based on clinical grounds alone
In non-epidemic periods, acute watery diarrhea resulting in severe dehydration:
Dark-field microscopy of faecal material
Transportation of samples in alkaline peptone water and kept cool
Culture in selective media such as TCBS agar
Bio- and serotyping in the reference laboratory
Notify the infection!

28. CHOLERA PANDEMIC IN SOUTH AMERICA

29. CHOLERA OUTBREAK IN 2005
                                                               

30. Shigella – species and serogroups
SEROTYPE
S. dysenteriae A
1 – 15
S. flexneri B
1 – 6
(15 subtypes)
S. boydii C
1 - 18
S. sonnei D 1

31. EPIDEMIOLOGY OF SHIGELLOSIS
Shigella is causing 80 mil. of symptomatic infections and deaths each year
99% of infections are in developing countries
70% of cases and 60% of deaths at children under 5 years
The recent epidemics:
1969 – 73: Central America – 0,5 mil. of cases, of deaths
1993 – 95: countries of central and south Africa
1994: Rwandian refugies to DR of Congo ( of deaths during the first month)
1999 – 03: Sierra Leone, Liberien, Guinea, Senagal, …
2000: India a Banglades – resistance to FQ

32. EPIDEMIOLOGY OF SHIGELLOSIS
S. sonnei and S. boydii are causind ussually mild disease with watery or bloody diarrhea, they are more common in developed countries of temperate climate
S. flexneri is the main cause of endemic shigellosis in developing countries
S. dysenteriae typ 1 (Sd1, Shiga bacillus) is causing the most serious disease, it is causing epidemies in developing countries

33. Shigella dysenteriae serotype 1
It deffer from other species:
It produces a potent cytotoxin (Shiga toxin)
It is causing more severe, long-lasting, potentially deadly diarrhea
The resistance to antibiotics is more common
It may cause large, often regional epidemics:
„high attack rates“
„high case fatality rates“

34. DYSENTERY SYNDROME Diarrhea with blood and pus
Abdominal pain and cramps
Tenesms

35. DIFFERENTIAL DIAGNOSTICS
Entamoeba histolytica
Campylobacter jejuni
Entheroinvasive E. coli
Enthero-hemorrhagic E. coli
Salmonella sp.
Intentestinal schistosomosis (Schistosoma mansoni, S. japonicum)