Clinical infections - Gastrointestinal 1

Question 1

Sterile sites:

Answer 1

peritoneal space, pancreas, gall bladder, liver (wouldn’t expect bacterial growth)

Question 2

Non-sterile sites

Answer 2

intra-luminal so from top to the bottom end: mouth, oesophagus, stomach, small/large bowel

Question 3

Normal Flora

Answer 3

• Enterococcus – found in the enteric tract
• Nose: staphylococcus aureus
• Mouth: streptococci viridans
• Pharynx: contain haemophilus

Question 4

Angular Cheilitis definition

Answer 4

• Acute/chronic inflammation of skin and contiguous labial mucosa located at lateral commissures of mouth

Question 5

Angular Cheilitis aetiology

Answer 5

• Caused by excessive moisture [maceration] from saliva and secondary infection with C albicans or less commonly S aureus

Question 6

Angular Cheilitis treatment

Answer 6

Topical Antifungals or Antibiotics

Question 7

Angular Cheilitis presentation

Answer 7

• Older people: Loss of vertical dimension of the mouth, drooling, saliva
• Erythema, maceration, scaling, fissuring at corners of mouth

Question 8

Hairy Leucoplakia

Answer 8

• White plaques on the tongue seen in HIV patients who have not been treated
• caused by Epstein Barr Virus, cause of glandular fever

Question 9

Dentoalveolar infections

Answer 9

• Caries - Bacterial plaques form on the tooth surface and form caries, Acid produced by Streptococcus mutans and lactobacillus spp
• Pulpitis: Require root canal treatment
• Periapical abscess - Streptococci and anaerobes

Question 10

Periodontal infection

Answer 10

• Plaque beneath the gingival margin
• Gingivitis - requires improved oral hygiene
• Periodontitis -Progression of gingivitis - Antibiotics required
• Periodontal abscess - requires surgical draining
• Acute necrotizing ulcerative gingivitis - Can lead to DNSI’s - requires antibiotics

Question 11

Peritonsillar abscess (quinsy abscess)

Answer 11

• Unilateral swellings of the tonsil; caused by Streptococcus pyogenes
• Signs: muffled voice, trismus: lock jaw
• Symptoms: dysphagia, unilateral sore throat
• Treatment: Surgical drainage and antibiotic management

Question 12

Acute suppurative parotitis

Answer 12

• Non mumps; occurs in patients with poor oral hygiene and dehydration
• Almost always caused by Staphylococcus aureus
• Treatment: surgical drainage, antibiotics administered

Question 13

Submandibular space infections (Ludwig’s angina)

Answer 13

• Bilateral infection of submandibular space, potential for airway obstruction
• Abscesses form: surgical drainage required, antibiotics administered

Question 14

Helicobacter pylori infection definition

Answer 14

• Bacterial urease hydrolyses gastric luminal urea to form ammonia that helps neutralise gastric acid and form a protective cloud around the organism so it can penetrate the gastric mucus layer

Question 15

Helicobacter pylori infection diagnosis

Answer 15

• Cause pain, bleeding, perforation, ulcers. Diagnosis:
• Urease breath test - research
• Faecal antigen test – Best way to diagnose

Question 16

Helicobacter pylori infection treatment

Answer 16

• Triple antibiotic therapy plus PPI for 7-14 days – PPIs prevent acid secretion so conditions are no longer optimal for bacteria

Question 17

Biliary Tract Infection: Cholangitis

Answer 17

• The classic presentation is fever, abdominal pain, and jaundice (Charcot’s triad)
• Site: common bile duct
  Elevations in:
• serum alkaline phosphatase (ALP)
• gamma-glutamyl transpeptidase
• bilirubin
• Colonic bacteria: Enterobacteriaceae

Question 18

Biliary Tract Infection: Cholecystitis

Answer 18

• Abdominal pain, fever, history of fatty food ingestion
• Elevation in the serum total bilirubin and alkaline phosphatase concentrations
• Murphy’s signs: positive = pain on inspiration
• Site: Gall bladder - associated with stones
• Treatment: antibiotics +/- surgical

Question 19

Bacterial overgrowth of small intestine

Answer 19

• Overgrowth of bacteria on small bowel is believed to be associated with malabsorption or chronic diarrhoea
• Overgrowth of bacteria may result from achlorhydria, impaired motility, blind loops of bowel
• Treatment: dietary changes, surgical, motility, non-absorbable antibiotics

Question 20

Whipple’s Disease aetiology

Answer 20

• Tropheryma whipplei - found everywhere in environment

Question 21

Whipple’s Disease symptoms

Answer 21

• Joint symptoms, chronic diarrhoea, malabsorption, and weight loss
• joint and GI “pain”

Question 22

Whipple’s Disease pathology in distal duodenum

Answer 22

White plaques representing engorged lymph vessels

Question 23

Liver abscess

Answer 23

• Occurs if cholangitis is not treated and bacteria travel up biliary tree, into liver
• Infection ascends biliary tract, enters the bloodstream via portal vein, Haematogenous spread
• Commonly entamoeba histolytica

Question 24

Liver abscess investigations

Answer 24

• Serum alkaline phosphatase is elevated in 67 to 90 percent of cases and serum bilirubin and aspartate aminotransferase concentrations are elevated in about one-half of cases
• Protozoal infections and Viral hepatitis another cause

Question 25

Mycobacterium Tuberculosis

Answer 25

- TB in GI tract, mainly respiratory illness - Ileo-caecal tuberculosis is the most common GI site - gastric ulcers giving gastric outflow obstruction

Question 26

Complicated Intra-Abdominal Infection definition

Answer 26

Infection of the GI tract that extends beyond the hollow viscus of origin into the peritoneal space and is associated with either abscess formation or peritonitis - complicated need rapid surgical intervention and treatment

Question 27

Uncomplicated infections that can become complicated

Answer 27

``` o Cholecystitis o Diverticulitis o Appendicitis o Gastric/duodenal ulcer - C diff infection ```

Question 28

Intra-peritoneal abscess

Answer 28

- Anaerobes most likely cause | - Localised area of peritonitis with build-up of pus/faeces

Question 29

Intra-peritoneal abscess predisposing factors

Answer 29

- Perforation (may be result of surgery) - Mesenteric ischemia/bowel infarction - Pancreatitis/pancreatic necrosis - Penetrating trauma - Postoperative anastomotic leak

Question 30

Intra-peritoneal abscess treatment

Answer 30

- Generally, require drainage - Drainage: surgical or radiological; combined with antimicrobial therapy

Question 31

Swinging pyrexia

Answer 31

- Fever (different to most infections), temperature going up and down, abscess get bigger and bigger and periodically release pus and then peak in temp

Question 32

Subphrenic abscess

Answer 32

- between diaphragm, liver and spleen | - Pain in shoulder on affected side, persistent hiccup, intercostal tenderness, apparent hepatomegaly

Question 33

Pelvic abscess

Answer 33

- Urinary frequency | - Tenesmus: continuation/recurrent inclination to evacuate the bowels, caused by disorder of the rectum or illness

Question 34

Post-Operative Infection

Answer 34

- Superficial Surgical Site Infection: SSI-S - Deep Surgical Site Infection: SSI-D - Organ space SSI: SSI-O o Within 30 days of surgery or 1 year if prosthetic infection

Question 35

Spontaneous Bacterial Peritonitis (SBP) definition

Answer 35

- Ascitic fluid infection without an evident intra-abdominal surgically treatable source

Question 36

Spontaneous Bacterial Peritonitis (SBP) diagnosis

Answer 36

- Positive ascitic fluid bacterial culture - Elevated ascitic fluid absolute - Polymorphonuclear leukocyte (PMN) count. - Should be clear, milky appearance = infection

Question 37

Spontaneous Bacterial Peritonitis (SBP) aetiology

Answer 37

- Bacteria within gut lumen cross intestinal wall into mesenteric lymph nodes - Lymphatics carrying the contaminated lymph ruptures

Question 38

Spontaneous Bacterial Peritonitis (SBP) Presentation

Answer 38

- The vast majority of patients with SBP have advanced cirrhosis with ascites

Question 39

Spontaneous Bacterial Peritonitis (SBP) treatment

Answer 39

- Treatment is based upon antibiotics; antibiotic prophylaxis may be given - Surgically treatable infections, e.g. perforated duodenal ulcer, that lead to ascitic fluid infection are called secondary bacterial peritonitis

Question 40

Antibiotic prophylaxis for SPB be given to the following patients

Answer 40

o Patients with cirrhosis and GI bleeding o Patients who have had one+ episodes of SBP o Patients with cirrhosis and ascites along with either impaired renal function or liver failure

Question 41

Colonic Malignancy

Answer 41

- Patients with bowel cancer can present with a bacteraemia caused by S. gallolyticus

Question 42

Colonic Malignancy

Answer 42

- Patients with bowel cancer can present with a bacteraemia caused by S. gallolyticus

Question 43

Abdominal conditions that require antibiotics

Answer 43

- Appendicitis - Complicated diverticulitis- antibiotics and surgery - Pancreatitis - Antibiotics should be withheld until infection is proven with positive cultures - Oesophageal rupture