Infections: Gastroenteritis Flashcards
Acute traveller’s diarrhoea is most commonly caused by which bacteria? [1]
enterotoxigenic E. coli
What is the most common cause of viral gastroenteritis in children? [1]
rotavirus
What is the second most common cause of traveller’s diarrhoea? [1]
Camopylobacter jejuni
How do you treat Campylobacter jejuni infection? [3]
- Clathromycin (1st line)
- Azithromycin
- Ciprofloxacin
A patient has recently eaten fried rice left at room temperature. They are reported vomitting and then diarrhoea.
What is the most likely pathogen causing these symptoms? [1]
Bacillus cereus
How can you differentiate between Bacillus cereus causing diarrhoea compared to other infective agents? [1]
Bacillus cereus causes vomiting for 5hrs; then diarrhoea for 8hrs
What syndrome can Shigella cause? [1]
Name two treatments [2]
haemolytic uraemic syndrome:
Treatment of severe cases is with azithromycin or ciprofloxacin.
A patient presents with diarrhoea, right sided abdominal pain and fever.
What is the most likely cause of infection? [1]
What is a differential diagnosis? [1]
Yersinia enterocolitica: diarrhoea, right sided abdominal pain and fever.
Right sided abdominal pain is caused by mesenteric lymphadenitis (inflammation in the intestinal lymph nodes): appears like appendicitis}
Which parasite is found in the small intestines of mammals and causes diarrhoea via a faecal-oral transmission? [1]
Giardia lamblia
How do you treat Giardia lamblia? [2]
tinidazole or metronidazole
A faecal stool sample was sent, and the results this morning are as follows:
C. difficile toxin -ve
C. difficile antigen +ve
What is the next step in the management of this patient? [1]
Explain your answer [1]
C. difficile antigen positivity only shows exposure to the bacteria, rather than current infection
If the toxin is positive, it means the bacteria is actively replicating and is likely the cause of the diarrhoea.
If the antigen is positive in isolation, it merely means the bowel is colonised with C. difficile, and not necessarily causing diarrhoea.
Reassure and continue monitoring symptoms
Which drug classes are risk factors for C. diff infection? [2]
Antibiotics
PPIs
The [] is key in determining the severity of C. difficile infection
The white cell count is key in determining the severity of C. difficile infection
Which antibiotics are most likely to cause C. difficile infection? [2]
Second and third-generation cephalosporins are now the leading cause of C. difficile.
Clindamycin is historically associated with causing C. difficile but the aetiology has evolved significantly over the past 10 years.
C. difficile: think C!
Which overall type of pathogen most commonly causes gastroenteritis in children? [1]
Name the three most common pathogens [3]
Viral gastroenteritis is most common. It is highly contagious. Common causes are:
* Rotavirus
* Norovirus
* Adenovirus is a less common cause and presents with a more subacute diarrhoea.
Describe the relationship between E. coli and haemolytic uraemic syndrome (HUS) [2]
E. coli 0157 produces the Shiga toxin: This causes abdominal cramps, bloody diarrhoea and vomiting.
- The Shiga toxin destroys blood cells and leads to haemolytic uraemic syndrome (HUS).
Describe a risk factor for HUS [1]
The use of antibiotics increases the risk of haemolytic uraemic syndrome, therefore antibiotics should be avoided if E. coli gastroenteritis is considered.
Eating raw or undercooked pork OR spread through contamination with the urine or faeces of other mammal such as rats and rabbits.
This refers to gastroenteritis can caused infection by which pathogen? [1]
Describe the presentation [4]
Yersinia Enterocolitica
- Yersinia most frequently affects children
- causing watery or bloody diarrhoea
- abdominal pain
- fever
- lymphadenopathy
What is the incubation period like of Yersinia Enterocolitica like? [1]
How long does infection last? [1]
Incubation is 4 to 7 days and the illness can last longer than other causes of enteritis with symptoms lasting 3 weeks or more.
Describe how Shigella is spread [1]
What is the incubation period like? [1]
What is the treatment like? [2]
Shigella is spread by faeces contaminating drinking water, swimming pools and food.
The incubation period is 1 to 2 days and symptoms usually resolve within 1 week without treatment.
- Treatment of severe cases is with azithromycin or ciprofloxacin.
Describe the presentation of Shigella gastroenteritis [3]
It causes bloody diarrhoea, abdominal cramps and fever. Shigella can produce the Shiga toxin and cause haemolytic uraemic syndrome.
What is a key indicator that a patient is suffering from H.U.S? [2]
Blood diarrhoea and AKI symptoms
How do you distinguish between bacterial and viral gastroenteritis?
Bacterial gastroenteritis:
- usually presents with high fever and severe diarrhoea, which is commonly bloody.
Viral gastroenteritis is a self-limiting condition which lasts < 14 days. The most common symptoms include:
- Acute diarrhoea
- Vomiting (80%)
- Mild fever (40%)
- A short viral prodrome may occur before the onset of diarrhoea, consisting of mild fever and nausea or vomiting.
NB: A temperature >39°C in adults or >38°C in children under 3 months old should raise suspicion of bacterial pathology.
Describe the typical presentation of:
- Escherichia coli [3]
- Giardiasis [1]
- Cholera [2]
Describe the typical presentation of: [3]
Escherichia coli:
* Common amongst travellers
* Watery stools
* Abdominal cramps and nausea
Giardiasis:
- Prolonged, non-bloody diarrhoea
Cholera:
* Profuse, watery diarrhoea
* Severe dehydration resulting in weight loss
Describe the typical presentation of:
- Shigella [2]
- Staph aureus [2]
- Campylobacter [3]
Describe the typical presentation of:
- Bacillus cereus [2]
- Amoebiasis [2]
Incubation period
1-6 hrs: [2]
12-48 hrs: [2]
48-72 hrs: [2]
> 7 days: [2]
Incubation period:
1-6 hrs: Staphylococcus aureus, Bacillus cereus
12-48 hrs: Salmonella, Escherichia coli
48-72 hrs: Shigella, Campylobacter
> 7 days: Giardiasis, Amoebiasis
What are the treatments for the following: [+]
- E. coli
- Gardiosis
- Cholera
- Shigella
- Staph aureus
- Campylobacter
- Bacillus cereus
- Ameobiosis
Escherichia coli
- Gram Negative Rod
- Mx - Self Limiting
Giardiasis
- Flagellate Protozoan
- Mx - Metronidazole
Cholera
- Gram Negative Curved Rod
- Mx - 1. Doxycycline or 2. Ciprofloxacin
Shigella
- Gram Negative Rod
- Mx - 1. Ciprofloxacin or 2. Azithromycin
Staphylococcus aureus
- Gram + Cocci - Clustered (Grapes)
- Mx - Self Limiting
Campylobacter
- Gram Negative ‘Spiral’ Curved Rod
- Mx - Clarithromycin
Bacillus cereus
- Gram + Rod
- Mx - Mild = Self Limiting OR Severe = Vancomycin
Amoebiasis
- Mx - Metronidazole + Diloxanide Furoate (Intraluminal Agent)
