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.