Week 2 GI & ENT Flashcards
(37 cards)
What are the common GIT infections?
- Bacterial gastroenteritis
- Viral/Parasitic gastroenteritis
- Amoebiasis
- Giardiasis
- Toxic megacolon
What are the common intra-abdominal infections?
- Peritonitis
- Cholecytitis
- Diverticulitis
- Intra-abdominal, liver or pancreatic abscess
- Peptic ulcer disease
What are the common ENT infections? (10)
- Pharyngitis
- Diphtheria
- Epiglottitis
- Otitis externa
- Otitis media
- Mastoiditis
- Sinusitis
- Conjunctivitis
- Keratitis
- Endophthalmitis
What are the common organisms causing bacterial GE?
- Salmonella spp (mostly S enteriditis, S typhi & S paratyphi)
- Shigella spp
- Campylobacter jejuni
- Vibrio spp
- Clostridium difficile
How are the common Salmonella spp transmitted and what GI infection do they cause?
Causes bacterial GE
Salmonella enteriditis
- Most common
- Transmitted through food
- Usually self-limiting
Salmonella typhi (typhoid fever) & Salmonella paratyphi
- Causes more dangerous manifestations
- P.t. transmitted by water
- P.p transmitted from person-to-person (eg ingestion of fecal-contaminated food/water)
- Must be treated with antibiotics
- Not endemic in Singapore
How is shigella spp transmitted and what GI infection does it normally cause?
- Can cause bacterial GE
- Transmitted from person-to-person
- Disease is usually self-limiting
How is Campylobacter jejuni transmitted and what GI infection does it normally cause?
- Can cause bacterial GE
- Transmitted through food (mostly chicken)
- Usually self-limiting
How is Vibrio spp transmitted and what GI infection does it normally cause?
- Can cause bacterial GE
- Transmitted through raw seafood
- Usually self-limiting
Note: Vibrio cholera
- Causes the most serious effects, and can cause death
- Transmitted through water
- Common indicator is “rice water stool”
How is Clostridium difficile transmitted and what GI infection does it normally cause?
- Can cause bacterial GE
- Starts off with antibiotic exposure and then transmitted person-to-person
- Especially common in hospital environments
- Treatment involves stopping the current antibiotic and replacing it with one that targets the GI
- Dangerous as it can lead to colitis, toxic megacolon or death
What is haemolytic uraemic syndrome?
- Serious condition affecting the kidneys
- Caused by EHEC/E.coli strain 0157
- Transmitted through contaminated food or water
What samples and tests do you send for to test for Salmonella spp, Shigella spp, Vibrio spp and Campylobacter causing bacterial GE?
- Stool sample
- Culture and sensitivity test
- TAT 24-48 hours
What samples and tests do you send to test for C. difficile causing bacterial GE?
- Stool
- C. diff toxin test
- C&S not done as C. diff is hard to grow
What are the common viruses that cause viral GE?
- Norovirus
- Rotavirus
- Adenovirus
note: all these viruses are common in children and in nurseries
How is Norovirus transmitted and what GI infection can it cause?
- Viral GE
- Can lead to uncontrolled diarrhea and vomiting (easily spread in hospitals)
- Transmitted through contaminated food/shellfish/water and fecal-contaminated sources
- Usually self-limiting
How are Rotavirus and Adenovirus transmitted and what GI infection can it cause?
- Viral GE
- Commonly causes paediatric diarrhea
- Transmitted person-to-person
- Usually self-limiting
What samples and tests do you send to test for rotavirus, adenovirus and norovirus causing viral GE?
- Stool sample
- Enzyme immunoassay (EIA) test and/or
- Polymerase chain reaction (PCR) test
- C&S not done as viral cultures takes too long to grow
Cause and diagnosis of Amoebiasis?
- By Entamoeba histolytica parasite
Diagnosis through
- Microscopy of stool specimens (to visualise parasite)
- Blood serology if systemic infection is suspected
Systemic infection
- More dangerous
- Usually abscess in the liver
- Pus will look like anchovy sauce
Cause and diagnosis of giardiasis?
- Giardia parasite (G. intestanalis, lambia, duodenalis)
- Diagnosis through stool microscopy
Cause and diagnosis of toxic megacolon?
- Microbe cause: C. difficile
- PP cause: Inflammatory bowel disease, ischemic colitis, medicinal drugs, other inflammatory conditions
- Common in elderly due to use of many antibiotics
Impending signs:
- Distended abdomen but no diarrhea/output
- Antibiotics alone is not enough to treat
Brief on the other intra-abdominal infections and what microbes can cause them?
- Cholecystitis (infl of gallbladder) leading to cholangitis (infl of bile duct)
- Diverticulitis (infl of intestines)
- Abscesses
Caused by:
- Coliforms (eg E. coli, Klebsiella, Enterobacter)
- Anaerobes
- Enterococci
- P. aeruginosa
- Candida
What is the pathophysiology of peritonitis?
- Usually due to the perforation of intestines, gallbladder or other organs within the abdomen and spills over into the sterile peritoneum
- May also be due to C. diff toxins
Primary:
- Liver disease -> ascites -> spontaneous bacterial peritonitis
Secondary:
- Associated with peritoneal dialysis
What pathogens can cause peritonitis?
Primary:
- Coliforms
- Pseudomonas aeruginosa
- Anaerobes
- Enterococci
- Candida
Secondary:
- Primary +
- Coagulase-negative Staphylococcus (Skin flora)
- Staph aureus
- Other environmental bacteria (due to foreign object)
Cause and pathophysiology of peptic ulcer disease?
- Helicobacter pylori
- Bacteria can survive due to urease production (neutralises stomach acid)
- Chronic condition may lead to stomach cancer
- Gastric biopsy may be needed if repeated courses of Abx does not work
What is the most common first line of antibiotics?
Ceftriaxone
