Pseudomembranous Colitis and other Clostridiodes difficile Infections and Cholera Flashcards
Cholera and Clostridiodes difficile – both cause gastrointestinal infections
T/F
T
Cholera is caused by ________
vibrio cholerae
Clostridoides difficile causes a range of gastrontestinal infections including __________
pseudomembranous colitis
What is Cholera?
(acute or chronic?) and (mild or severe?) diarrheal disease of Public health importance
Primarily transmitted within the community
Caused by _____________ contaminated with the bacterium Vibrio cholerae.
Acute ; severe
consuming food and water
Cholera
Affects only adults
Affects both Adults and Children.
Incubation Period for cholera is ______ to ________ after exposures
12hrs to 5 days
Vibrio Cholera
These are Gram-__________ ——- .
———- shaped
(Obligate or facultative?) (aerobes or anaerobes?) which are oxidase ________.
negative; rods
comma
facultative
anaerobes; positive
The most important vibrio, __________
Vibrio cholerae
Vibrio Cholera
V. cholerae is found in the ______ of an infected individual and ends up in the _________ if _______ is untreated.
Transmission – by drinking contaminated water or Contaminated food
Survives in fresh water and in salt water Primarily a disease of _________..
feces
water supply; sewage
poverty
Vibrio Cholerae
There are many serogroups of V. cholerae,
Only two –_____ and _______ – cause outbreaks.
O1 and O139
Vibrio Cholerae
V. cholerae ____ - caused all recent outbreaks.
V. cholerae _____ – first identified in Bangladesh in 1992 – has never been identified outside Asia.
_____ difference in the clinical presentation of the two sero-groups.
O1
O139
No
Vibrio Cholerae
V. cholerae O1 - caused ________
V. cholerae O139 – first identified in _______ in 1992 – has never been identified outside Asia.
all recent outbreaks.
Bangladesh
Epidemiology of Cholera
Cholera can be __demic or ___demic
en
epi
Cholera
Endemic: defined as _______________ cases were detected during the ___________ with evidence of ________
Epidemic:
•In cholera endemic countries an outbreak represents a _______________________
•In a non-endemic country an outbreak is defined as the occurrence of ____________________ case of cholera with evidence of ___________ in an area where there is not usually cholera.
confirmed cholera
last 3 years; local transmission
greater than expected number of cases.
at least 1 confirmed ; local transmission
Transmission of cholera
Linked to inadequate access to ________ and sanitation services
Drinking contaminated water
Eating contaminated food
Direct Person to person uncommon in the community
About ____% of people infected with cholera do not develop any symptoms and remain carriers
Pathogens persist in faeces for ____ to ____ days and are shed into the environment
clean water
75
1 to 10
Factors that Aid Transmission of cholera
•Pathogen factors:
________ of ______ in the environment.
Presence of a ___________
•Reservoir and carrier state:
_____ is the only known reservoir
convalescent carrier may be infectious for __________
chronic carriers can remain infectious for _________, up till _______
Persistence of bacteria
potent exotoxin.
Man; 2-3weeks
a month; 10 years.
Factors that Aid Transmission of cholera
•Host factors:
Over crowding
Cholera incidence higher among lower socio economic groups which may be attributable to _________
•Environmental factors:
poor environmental sanitation; this results in contamination of food
and water.
poor hygiene.
Pathogenesis Of cholera
Once in the gut,
Organism _______________ of the intestine without __________.
______________ is important in pathogenesis.
__________ (_________) is then secreted and is chromosomally encoded and contains __________________ (_______)
adheres to the epithelium
penetration; Adhesion to the microvilli
Choleragen ; Cholera toxin
two types of subunit (A and B).
Pathogenesis of cholera
The B subunit binds to _______ on epithelial cell surfaces allowing ______________
The A subunit catalyses _________ of a regulator complex which in turn activates ________ present in the cell membrane of the epithelium of the gut.
The overproduction of ______ stimulates ______________________ into the lumen.
Results in _______ and death (without treatment) result.
gangliosides; internalization of the A subunit.
ADP-ribosylation ; adenylate cyclase
cyclic AMP
massive secretion of ions and water
dehydration
Clinical presentation of cholera
________ stool (_______)
Vomiting,Leading to ________________
Less than ____% of total cholera cases develop into severe cases of dehydration
Without any treatment, deaths may reach as high as 50% during outbreaks
Watery Colorless; rice water
moderate to severe dehydration
10
Treatment of cholera
__________ is the major component of treatment.
Antibiotic therapy (including ________) is additionally used.
Fluid replacement
tetracycline
Vaccination against cholera is completely effective generally recommended.
T/F
F
Vaccination against cholera is only partially effective and not generally recommended. - commonly used by international travelers.