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.
Cholera Vaccine is commonly used by international travelers.
T/F
T
Safe oral cholera vaccines should be used in conjunction with ________ and _________ to control cholera outbreaks and for prevention in areas known to be high risk for cholera
improvements in water and sanitation
Pseudomembranous colitis
________ of the _____ due to an overgrowth of Clostridioides ________
pseudomembranes
Characterized by elevated ________ plaques that ______ to form _____________ on the mucosa.
Common cause of diarrhea after ____________
More common in people over _____yrs
Inflammation; colon
difficile; yellow- white
coalesce; pseudomembranes
antibiotic use
65yrs
Clostridiodes difficile
Gram ________,
_______ oval spores, capsule in some
most are (motile or non-motile?) .
Ubiquitous especially in ___________
positive
subterminal
Motile ; hospital environment
Clostridiodes difficile
Serogroups:list them
Virulence factors:——- and ______
Toxin A & Toxin B,
Clostridiodes difficile
Toxin A is _______ toxin,
Toxin B is _______toxin and both work together in-vivo.
entero
cyto
Risk factors of Pseudomembranous colitis
I
taking _______
Staying in the hospital or a nursing home
Increasing age, especially over ____ years
Having a weakened immune system
Having a colon disease, such as inflammatory bowel disease or _______
Undergoing intestinal ________
Receiving chemotherapy treatment for cancer
antibiotics
65
colorectal cancer
surgery
Pathogenesis:
C. difficile spores -resistant many common disinfeprofessionalsctants
•Can be no
Disturbance of normal colonic flora with antibiotics, cytotoxic drugs, surgery, instrumentation
•
Eg_____,______ - devastating effect on the flora of the colon.
•
Others include ______,________,_______
Lincomycin and clindamycin
cephalosporins, ampicillin, tetracycline
Pathogenesis Of pseudomembrane colitis:
Leads to
_________ of C.difficile
Intra-abdominal __________
_________ of mucosal lining ______ of fluid
_______ of colonic mucosa
____________ and ___________
Overgrowth
production of toxins
Inflammation
Outpouring
Necrosis
Fibrinous exudate and pseudomembrane Bloody diarrhoea.
Clinical presentation of C.difficile
infections
A spectrum of disease
• Antibiotic associated ________
Antibiotic associated _____
______________________
diarrhoea
colitis
Pseudomembranous colitis
Clinical presentation of C.difficile
infections
A spectrum of disease
• Antibiotic associated diarrhoea _________%
Antibiotic associated colitis _______%
Pseudomembranous colitis _________%
15 –25
25-50
greater than 95
Clinical presentation of C.difficile
infections
All ages may be affected but primarily a disease of the ________ and ___________
Children appear to be ________ to the disease through carriage is highest in children under ______.
elderly and debilitated.
refractory
2yrs
Pseudomembranous colitis
Most cases are ________ acquired
hospital
Pseudomembranous colitis
Community-acquired C. difficile
Reported in people with no known risk factors, including people with no recent health care contact or use of antibiotics.
Often due to _________ of C. difficile that _____________
an aggressive strain
produces far more toxins than other strains do.
Pseudomembranous colitis
Complications
_________
______ failure
Perforation
Toxic ————-
Death
Dehydration
Renal
megacolon
Prevention of C.dificile
Avoid ________ antibiotic use
Wash your hands with soap and warm water
Contact precautions:_____ patients and wear disposable gloves and isolation gowns while in the room until at least _________ after diarrhoea stops
Good environmental cleaning
All surfaces should be carefully washed and disinfected with a product that contains _________
unnecessary
Isolate
48 hours
chlorine bleach
If you don’t keep raw foods—such as beef, poultry, seafood, and eggs—separate from other foods, microbes from the raw foods can spread to other foods
T/F
T
Microbes can also spread from raw foods to your hands, kitchen utensils, cutting boards, and kitchen surfaces during food preparation
T/F
T
If you don’t wash your hands, utensils, cutting boards, and surfaces completely after they have come into contact with raw foods, they can spread microbes to other foods
T/F
T
Infections with microbes—viruses, bacteria, and parasites—cause most food poisoning
T/F
T
Harmful chemicals also cause some cases of food poisoning
T/F
T
Common symptoms of food poisoning include
______ or _______
______
______ in your abdomen
______
headache
Symptoms range from mild to severe and may last from a few hours to several days.
diarrhea or bloody diarrhea
vomiting
pain in your abdomen
fever
Less commonly, some types of food poisoning—such as ________, ________ poisoning —can affect
your ________ system and Symptoms may include
________
________
________
________
________
botulism
fish and shellfish poisoning
Nervous
blurred vision
headache
paralysis
tingling or numbness of your skin weakness
Many types of bacteria can cause food poisoning, including certain species of
________
certain types of _______
certain species of __________
_________
______________
certain species of _____
Listeria _________
Salmonella
certain types of Clostridium
certain species of Campylobacter
Staphylococcus aureus
Escherichia coli
certain species of Vibrio
Listeria monocytogenes
Many types of bacteria can cause food poisoning, including certain species of
Salmonella – _______
certain types of Clostridium, including the common _________ and the less common _________, which causes an illness called _______
certain species of Campylobacter, including __________
Staphylococcus aureus
Escherichia coli
certain species of Vibrio
Listeria monocytogenes
non-typhi
C. perfringens
C. botulinum; botulism
C. jejuni
The pathogenesis of foodborne gastroenteritis can be broken down into 3 main mechanisms, namely:
Pathogens that _____________ ______ it is consumed (________ toxin)
Pathogens that make a toxin ___________ _____ the food is ingested
Pathogens that _________________ and ___________, releasing factors that cause an inflammatory diarrhea.
make a toxin in the food before ; preformed
in the gastrointestinal tract, after
invade the bowel wall and directly break down the epithelial lining
Pathogenesis Of food poisoning
Enterotoxins productions: (eg, _________, _________ strains of E. coli)
They adhere to ________________
These toxins ____________ and cause _________ and ________ by stimulating adenylate cyclase, resulting in _________
_________ produces a similar toxin
Vibrio cholerae; enterotoxigenic
intestinal mucosa without invasion
impair intestinal absorption
secretion of electrolytes and water
watery diarrhea
C. difficile
Pathogenesis Of food poisoning
Exotoxins are produced by some organisms (eg, ________,_______,________)
The exotoxin can cause gastroenteritis without ________
These toxins generally cause (acute or chronic?) nausea, vomiting, and diarrhea within ______ of ingestion of contaminated food
Symptoms abate within ________
Staphylococcus aureus, Bacillus cereus, Clostridium perfringens)
bacterial infection
Acute ; 12 hours; 36 hours.
Pathogenesis of food poisoning
Mucosal invasion occurs with some organisms (eg, _______,________, _______, ________, some E.
coli subtypes) that invade the mucosa of the small bowel or colon and cause _________,________, exudation of ______- rich fluid, and secretion of electrolytes and water
The invasive process and its results can occur ————————-
The resulting diarrhea has evidence of this _____ and ________ with ______ and _____ present on microscopy and sometimes with gross blood.
Shigella, Salmonella, Campylobacter, C. difficile
ulceration, bleeding
protein
whether or not the organism produces an enterotoxin
invasion and inflammation
WBCs and RBCs
Preformed toxins
________ and _______ produce heat-stable enterotoxins in the food before it is consumed
Transmission: These pathogens are usually transmitted by a food handler and often found in summer picnic foods
S aureus: grows well in __________________
Bacillus cereus: grows in _____ foods, such as _____, but is also found in _____, pork, and vegetables
Incubation period: ______. Ingestion of preformed toxins leads to (slow or rapid?) onset of symptoms.
Staphylococcus aureus and Bacillus cereus
Dairy, meat, eggs, and salads
starchy;rice; beef; 1–6 hours; rapid
Preformed toxins
These bacteria usually affect the __________, causing nausea, profuse vomiting, and abdominal pain/cramping.
The emetic enterotoxin can be found in __________ and the __________. Testing is rarely conducted, however, because illnesses are __________
There is ______ risk of person-to-person spread
Symptoms- (Gradual or Sudden?) onset of nausea and vomiting after eating suggests ingestion of a preformed toxin
small intestine; vomitus
food; self-limited
no
Sudden m
Preformed toxins
Diagnosis is usually made based on _________ and ________
Treatment -
No antibiotics needed because it is a _________ _________
_________ care and _________ antiemetics help control vomiting.
Prognosis: _________ _________ recovery in _________ is typical
history and food diary
preformed enterotoxin
Supportive ; parenteral
Rapid spontaneous ; 1 day
Pathogens that transmit illness by making a toxin after consumption C perfringens
Transmission: ingestion of __________ that have germinated in food products, such as beef, pork, home canned foods, and poultry1
Pathophysiology: Once spores reach the __________ , they produce __________, leading to __________ diarrhea.
Incubation: __________
Symptoms: frequent __________ and abdominal cramping; rarely, fever, nausea, and vomiting
spores
small intestine; enterotoxin; watery diarrhea
6–48 hours; watery stools
Pathogens that transmit illness by making a toxin after consumption C perfringens
Duration: usually ___________
Treatment: Rarely does a patient need _____________. Antibiotics are of ____ given the ______________________ in the short lived nature of this illness, but fecal _________ are present because this is an __________ gastroenteritis.
less than 24 hours
intravenous fluids
no use
short duration of symptoms
leukocytes ;inflammatory
.
Pathogens that transmit illness by making a toxin after consumption C perfringens
Prognosis: _________ , rarely lasting more than _________. Ingestion of _________ strain of these bacteria, however, can lead to a serious illness, _________(_________).
Symptoms include severe abdominal pain, vomiting, diarrhea, and possible _________ and can be rapidly fatal.
Prevention: Do not _________ that have already been cooked warm for long periods of time.
Self-limited ; 24 hours; type C
enteritis necroticans (pigbel)
shock; keep foods
