Session 9: GI Infections Flashcards by Don J

Define microbiome.

All the genome within the gut environment

How well did you know this?

Not at all

Perfectly

Define microbiota.

The organisms within the gut environment.

How well did you know this?

Not at all

Perfectly

Function of the gut microbiota.

Pathogen inhibition

Immune protection (GALT)

Nutrient metabolism (SCFA for the cells of the colon which is produced by the fermentation of dietary fibres)

Drug metabolism

Gut brain axis

How well did you know this?

Not at all

Perfectly

What are the most common presenting complaints in GI infections?

Diarrhoea

Vomiting

Pain

How well did you know this?

Not at all

Perfectly

What is important to ask the patient about diarrhoea?

Onset

Duration

Frequency

Consistency

How well did you know this?

Not at all

Perfectly

What is important to ask the patient about vomiting?

Onset

Frequency

How well did you know this?

Not at all

Perfectly

What is important to ask the patient about pain in GI infections?

Site

Radiation

Intermittent/continuous

How well did you know this?

Not at all

Perfectly

Give examples of other important questions to ask in GI infections.

Past medical history (Immunodeficient, other GI conditions)

Travel history (Where, when, how long, activities, food and drink, animal contact, travel companions etc…)

Drug history (recent antibiotics, PPis, Laxatives, Immunosuppressants)

Social history

How well did you know this?

Not at all

Perfectly

Give examples of GI examination important to do in GI infections.

Volume status

Mucous membranes

Blood pressure

Pulse

JVP

Abdominal examination

Ileus

Peritonitis

How well did you know this?

Not at all

Perfectly

What investigations are done in GI infections?

Stool culture

Enzyme immunoassay

PCR

Microscopy

How well did you know this?

Not at all

Perfectly

What is gastroenteritis?

Inflammation of the gastrointestinal tract leading to diarrhoea, vomiting and abdominal pain.

How well did you know this?

Not at all

Perfectly

Give examples of pathogens that can cause gastroenteritis.

E. coli

Salmonella

Shigella

Campylobacter

Cryptosporidium

Giardia

C. diff

Entamoeba histolytica

Norovirus

Rotavirus

Parasites

How well did you know this?

Not at all

Perfectly

How might diarrhoea present in gastroenteritis?

As watery diarrhoea or inflammatory diarrhoea.

How well did you know this?

Not at all

Perfectly

How is salmonella generally divided into?

Typhoidal salmonella (Salmonella typhi and Salmonella paratyphi)

Non-typhoidal salmonella (Salmonella enteritidis, Salmonella virchow, etc..)

How well did you know this?

Not at all

Perfectly

Where might you find salmonella?

Eggs

Poultry

Turtles

How well did you know this?

Not at all

Perfectly

What does Typhoidal salmonella generally cause?

Enteric fever

How well did you know this?

Not at all

Perfectly

What does Non-typhoidal salmonella primarily cause?

Gastroenteritis

How well did you know this?

Not at all

Perfectly

Incubation period of Non-typhoidal salmonella.

8-72 hours

How well did you know this?

Not at all

Perfectly

Transmission route of Non-typhoidal salmonella.

Contaminated food

Faeco-oral route

Animals

How well did you know this?

Not at all

Perfectly

General features of Non-typhoidal salmonella.

Watery diarrhoea

Nausea

Vomiting

Abdo cramps

How well did you know this?

Not at all

Perfectly

Complications of Non-typhoidal salmonella.

Bacteraemia, endovascular infections, abscesses, osteomyelitis, septhic arthritis.

How well did you know this?

Not at all

Perfectly

When might you see Non-typhoidal salmonella causing osteomyelitis and septic arthritis?

In patients with sickle-cell anaemia.

How well did you know this?

Not at all

Perfectly

Treatment of Non-typhoidal salmonella.

Usually self-limiting and resolve itself within a day or two.

However in case it is persisting:

Ciprofloxacin, azithromycin, ceftriaxone.

How well did you know this?

Not at all

Perfectly

Give common campylobacter pathogens.

Campylobacter jejuni

Campylobacter coli

How well did you know this?

Not at all

Perfectly

Where might you find Campylobacter?

In the GI tract of animals, especially poultry.

Incubation period of Campylobacter.

Roughly 3 days

Transmission route of Campylobacter.

Food Water Animal contact

General features of Campylobacter.

Abdominal cramping Watery or bloody diarrhoea May have fever and malaise

Complications of Campylobacter.

Reactive arthritis Guillain-Barré syndrome

Treatment of campylobacter.

Usually self-limiting. In immunocompromised patients, elderly or severe infections: Macrolides or fluoroquinolones can be given.

Give examples of Shigella.

Shigella dysenteriae 1 Shigella flexneri

What's important to note about such Shigella?

They can cause dysentery (bloody diarrhoea)

Incubation period of Shigella.

1-7 days

Transmission of Shigella.

Faeco-oral Food and water. Person to person can happen due to a **low infectious dose**.

General features of Shigella.

Fevers Frequent low volume bloody stools Tenesmus Nausea and vomiting is usually absent

Complications of Shigella. Intestinal: Systemic:

Intestinal complications are **rare** but include proctitis, rectal prolapse, toxic megacolon, perforation and obstruction. Systemic complications such as bacteraemia, seizures, reactive arthritis and haemolytic uraemia syndrome (HUS)

Treatment of Shigella.

Ciprofloxacin Azithromycin Ceftriaxone

Give examples of E. coli.

ETEC EPEC EIEC EAEC STEC

What is E. coli O157?

STEC (Shigella Toxin E. coli)

Transmission of E. coli O157.

Faeco-oral

What age groups are most vulnerable to E. coli O157?

Children under 10 years old and elderly.

Incubation period of E. coli O157.

1-10 days

General features of E. coli O157.

Painful and bloody diarrhoea. Often NO fever

Complications of E. coli O157.

HUS characterised by nonimmune-mediated haemolytic anaemia, thrombocytopenia and acute kidney injury.

Treatment of E. coli O157.

Fluid replacement and blood pressure agents. **Do not give antibiotics as they can worsen the condition and develop HUS.**

Explain what Clostridiodes difficile is.

Anaerobic gram negative bacilli. One of the most common nosocomial infections.

Risk factors of Clostridiodes difficile.

Age \>65 Antibiotic therapy PPI therapy Prolonged hospitalisation

Explain how antibiotics can cause Clostridiodes difficile infection.

C. diff can be found in the normal gut flora. However as antibiotics are given the gut flora can be disrupted and C. diff can prosper and start to grow. Colonisation of the GI tract through faecal oral route. This is exacerbated by antibiotic therapy which disrupts normal gut microbiota.

Give an important virulence factor of Clostridiodes difficile.

Produces spores which are very resistant and remain in the environment for a long time.

Complications of Clostridiodes difficile.

Toxic megacolon Colitis Perforation

Treatment of Clostridiodes difficile.

Metronidazole Oral vancomycin Fidaxomicin

What is norovirus more commonly called?

Winter vomiting virus/bug

Clinical features of norovirus.

Profuse diarrhoea and vomiting

Incubation of norovirus.

12-48 hours

Transmission of norovirus.

Faeco-oral Direct contact Aerosol It is highly infectious as the infective dose is 10-100 particles (which is very low for a virus)

Treatment of norovirus.

Usually self-limiting and resolves within 1-2 days. Can excrete for longer.

Where does norovirus cause outbreaks?

Hospital wards Nursing homes Nurseries Schools Cruise ships

Incubation period of rotavirus.

Less than 48 hours.

Transmission of rotavirus.

Faeco-oral Highly infective

General features of rotavirus.

Diarrhoea Vomiting Fever Usually young children have more severe disease than adults.

Treatment of rotavirus.

Usually self-limiting

Complications of rotavirus.

Seizures Encephalopathy Acute encephalitis They are very rare though

Explain Cryptosporidium.

Intracellular protozoan parasite and associated with sporadic water associated outbreaks. Affects all age groups but most frequently in children.

Transmission of Cryptosporidium.

Water Food Faeco-oral Person to person Animals

Incubation period of Cryptosporidium.

7-10 days

Treatment of Cryptosporidium.

Usually self-limiting within 10-14 days. Nitazoxanide

Clinical features of Cryptosporidium.

Watery diarrhoea Fever Nausea

High risk group of Giadria duodenalis.

A protozoan parasite that mainly affect infants, children, immunocompromised, travellers and CF patients.

Transmission of Giardia duodenalis

Food Water Faeco-oral

General features of Giardia duodenalis.

Malaise Steatorrhoea Abdo cramps Bloating Can be asymptomatic

Treatment of Giardia duodenalis

For symptomatic patients Metronidazole or nitazoxanide

What is Entamoeba histolytica?

Protozoan parasite that can cause amoebic dysentery or infection at extra-intestinal sites like amoebic liver disease.

Risk factors for severe Entamoeba histolytica disease.

Young age Corticosteroid therapy Pregnancy Malignancy Malnutrition Alcoholism

Incubation period of Entamoeba histolytica.

2 weeks to years

Transmission of Entamoeba histolytica

Food Water Faeco-oral

General features of Entamoeba histolytica.

Diarrhoea (can be bloody) Abdo pain Fulminant colitis with necrosis and perforation can occur. This means it can mimic IBD.

Treatment of Entamoeba histolytica.

High dose metronidazole followed by intraluminal agent like paromomycin

Infection and prevention control of gastroenteritis.

Prevent transmission Contact precautions Patient isolation and PPE Hand hygiene with soap water essential in diarrhoeal illness Terminal cleaning of patient environment.

Session 9: GI Infections Flashcards

(79 cards)