Made by- prakriti singh

Mbbs-11

CAUSES OF DIARRHEAL DISEASES

• According to WHO, diarrhea is defined as

increase in the frequency, fluidity or

volume of bowel movements, relative to the

usual habits of an individual. Passage of

three or more motions a day can be taken

as diarrhea.

DYSENTERY

• Dysentery means passage of blood and mucous with

motions, often associated with tenesmus.

GASTROENTERITIS

• It is often used as synonym for acute diarrhea,

especially when associated with vomiting. It may be

defined as inflammation of the mucous membrane of

stomach and intestine resulting in frequent loose

motions with or without mucous and with or without

blood, pain in abdomen and with or without fever.

TRAVELLER’S DIARRHOEA

• It is an acute diarrheal illness that sometimes occurs in

visitors from foreign countries, within a week or two of

arrival in developing country.

FOOD POISONING

• The term food poisoning means an illness acquired through

consumption of food or drink contaminated either with micro-

organisms, their toxins or chemical poisons.

• But traditionally, it is restricted to acute gastroenteritis

caused by microbial contamination of food.

ACCORDING TO CAUSATIVE AGENT

BACTERIA

VIRUSES

PROTOZOA

FUNGUS

BACTERIA1. VIBRIOS

(i) VIBRIO CHOLERAE

(ii) VIBRIO PARAHAEMOLYTICUS

(iii) VIBRIO MINISCUS

(iV) VIBRIO VULNIFICUS

2. ESCH. COLI

(i) ETEC ( Enterotoxigenic Esch. coli)

(ii) EPEC (Enteropathogenic Esch. coli)

(iii) EIEC (Enteroinvasive Esch.coli)

(iv) EHEC (Enterohaemorrhagic Esch. coli)

(v) EAEC (Enteroaggrevative Esch. coli)

3. SALMONELLAE

(i) SALMONELLA ENTERITIDIS

(ii) S. TYPHIMURIUM

4. SHIGELLA SPP.

5. CAMPYLOBACTER JEJUNI

6. CLOSTRIDIUM PERFRINGENS

7. CLOSTRIDIUM. DIFFICILE (antibiotic induced)

8. YERSINIA ENTEROCOLITICA

9. STAPHYLOCOCCUS. AUREUS

10. BACILLUS CEREUS

11. AEROMONAS HYDROPHILIA

VIRUSES

1. ROTAVIRUS

2. NORWALK VIRUS

3. ADENOVIRUS

4. ASTROVIRUS

5. CALCIVIRUS

PROTOZOA

1. ENTAMOEBA HISTOLYTICA

2. GIARDIA LAMBLIA

3. CRYPTOSPORIDIUM PARVUM

FUNGUS1. CANDIDA ALBICANS

ACCORDING TO PATHOLOGICAL AGENTS

1. TOXIN PRODUCERS

2. ENTEROADHERENT

3. CYTOTOXIN PRODUCERS

4. INVASIVE ORGANISMS

PATHOBIOLOGY/ AGENTS INCUBATION PERIOD

TOXIN PRODUCERS

(i) PREFORMED TOXINS

Bacillus cereus, Staphylococcus aureus,

Clostridium perfringens

(ii) ENTEROTOXINS

Vibrio cholerae, enterotoxigenic Escherichia coli, Klebsiella

pueumoniae, aeromonas species

1-8 hrs

8-25 hrs

8-27 hrs

ENTEROADHERENT

ENTEROPATHOGENIC AND ENTEROADHERENT

E.coli, Giardia organisms, Cryptosporiosis, helminths 1-8 days

CYTOTOXIN PRODUCERS

Cl. difficile

Hemorrhagic E.coli

1-3 days

12- 72 hrs

PATHOBIOLOGY /AGENTS INCUBATION PERIOD

INVASIVE ORGANISMS

(i) Minimal inflammation

Rotavirus and Norovirus

(ii)Variable inflammation

Salmonella, Campylobacter, and Aeromonas

species,

Vibrio parahaemolyticus, Yersinia

(iii)Severe inflammation

Shigella species, enteroinvasive E.coli, Entamoeba

Histolytica

1-3 days

12 hrs-11 days

12hrs- 8 days

ANTIBIOTIC INDUCED DIARRHEA

Disturbances of flora by antibiotic can lead to diarrhea by reducing the digestive functions or by allowing the overgrowth of pathogens such as Clostridium difficile

Antibiotic-associated diarrhea (AAD) results from an imbalance in the colonic microbiota caused by antibiotic therapy. Microbiota alteration changes carbohydrate metabolism with decreased short-chain fatty acid absorption and an osmotic diarrhea as a result.

Clostridium difficile, is known to account for 10 to 20% of antibiotic-associated diarrheal cases.

Many antibiotics are prone to cause psuedomembranous colitis. Active multipication of Cl. Difficile and the production by it of an enterotoxin as well as cytotoxinis responsible for antibiotic associated colitis.