Infection and Inflammation of the Gut Flashcards
What is Giradiasis?
Chronic, waterborne Protozoal infection
What are the symptoms of a Giardiasis infection?
Diarrhoea
Malabsorption
Weight loss
Asymptomatic
What is Giardiasis treated with?
Metronidazole
What subset of people are most likely to get a CMV infection?
Immunosuppressed patients
- organ transplant from seropositive donor associated with immunosuppressive therapy
- bone marrow transplant
- AIDS patients
What are the clinical signs of CMV infection?
Severe pain Loss of weight Weakness Remitting fever GI lesions - erosive-ulcerous - ulceronecrotic
What is Whipple’s disease?
Infection of the GI tract by Tropheryma whipplei
Patients have lack of immunity to the organism
What are the clinical signs of Whipple’s disease?
Weight loss
Arthralgia
Diarrhoea
Abdominal pain
How is Whipple’s disease diagnosed?
On biopsy of the duodenum
- shows PAS positive macrophages
What is tropical sprue?
Post-infectious sprue
Malabsorption disease
Affects people living in or visiting the tropics
What is the cause of tropical sprue?
E.Coli
Haemophilus
What is the pathophysiology of Tropical sprue?
Malabsorption disease that presents within weeks of an enteric infection
- flattening of villi
- inflammation of the lining of the small intestine
What is the treatment for tropical sprue?
Long course of tetracycline
Name the 6 intestinal diseases that can arise in an Entamoeba Histolytica infection.
Asymptomatic intralumincal ameobiasis-pass cysts
Dysentery
Acute necrotising colitis with perforation
Toxic megacolon
Ameboma
Perianal ulceration with fistula formation
Describe asymptomatic intraluminal ameobiasis-pass cysts.
Can involve any part of the bowel
Small foci of necrosis that progress to ulcers
- flask-shaped ulcer with narrow neck and broad base
Infection is initiated by ingestion of faecally contaminated food or water
Can spread to the liver, thorax and brain
Where can an amoeba infection spread?
Metastasis can occur overwhelmingly to the lover
- can spread from there to the thorax or even the brain
Rectovesicular fistula and fistulous involvement of the skin have been reported
What is pseudomembranous colitis and how is it diagnosed?
Swelling/inflammation of the large intestine due to overgrowth of C.Diff bacteria.
Loss of cypts
Diagnosed by C.Diff toxin found in the stool
What is the pathophysiology of pseudomembranous colitis?
Often prior treatment with antibiotics (e.g. clindamycin) causes elimination of many gut commonesuals and overgrowth of toxin, producing C.Diff
How is a mycobacterium tuberculosis infection of the colon diagnosed?
Biopsies show granulomatous inflammation with confluent granulomas, usually with central caseous necrosis
- contains multi-nucleate giant cells
Ziehl-Neelsen stain, culture and PCR can also identify the bacteria
What is the treatment of a mycobacterium tuberculosis infection?
Multiple antibiotics - Isoniazid. - Rifampin - Ethambutol - Pyrazinamide More aggressive treatment for multidrug resistant TB Surgery if the granuloma is perforated or obstructing - fish mouth stricture
Which parts of the colon is most commonly involved in colonic TB infections?
Cecum in conjunction with the ileum
- abundant lymphoid tissue
- often occurs in the absence of active pulmonary disease
How does the mycobacterium tuberculosis infection spread to the colon?
Swallowed bacteria
Haematogenous spread
Direct extension from infected lymph nodes or uterine tubes
What are the common clinical features of a colonic TB infection?
Weight loss Anorexia Fever Abdominal pain Diarrhoea Palpable mass
Name some possible endoscopic findings in colonic TB.
Strictures
Ulcers
Mucosal hypertrophy
What is a schistosomiasis infection of the colon?
A fluke that causes colitis or bowel obstruction
Associated with underdeveloped countries and living near a dam reservoir