Gastroenteritis Flashcards
• Demonstrate knowledge and understanding of the presentation and causation of diarrhoea caused by microbial infection (bacterial, viral and other organisms); and the patient groups at increased risk. • Demonstrate knowledge and understanding of the investigation of the patient presenting with diarrhoea possibly due to infection • Demonstrate knowledge and understanding of the initial treatment of patients presenting with infective diarrhoea • Demonstrate knowledge and understanding of Public
Normal defences of the GI tract
• Gastric acid
• Bile salts
• Lymphoid tissue
• Bowel flora
• Secretory IgE
• Motility
• Hepatic deactivation of toxins
Gastroenteritis presentation
• Fever
• Nausea and vomiting
• Abdominal pain and cramps
• Diarrhoea (acute vs chronic)
• Bloody diarrhoea
• Weight loss
Definition of dysentery
An inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhoea containing blood and mucus in the faeces with fever, abdominal pain, and rectal tenesmus caused by any kind of infection.
Bacterial causes
Salmonella
Campylobacter
E. coli*
S. aureus*
Bacillus species*
Vibrio cholera/parahaemolyticus
C. diff*
*induce toxin-mediated disease
Viral causes
Rotavirus
SRSV
Adenovirus
Astrovirus
Calcivirus
Protozoal causes
Giardia
Amoeba
Cryptosporidium
Helminths that cause
Strongyloids
Investigations
Stool microscopy/culture
• may require more than one sample
• ova, cysts and parasites in patients with recent travel, immunocompromise or with chronic diarrhoea
Stool toxin assay/PCR
• C. diff toxin
Blood cultures
• for bacteraemia (eg Salmonella)
Mucosal specimens
• duodenal, rectal biopsy - parasites
Serology
• Amoeba, Yersinia
Pros and cons of stool cultures
Remains most reliable method for bacteria
Slow
Use selective media to speed up and eliminate normal bowel flora
Half the weight of faeces is bacteria
Management
Fluids - IV or oral rehydration salts
Antibiotics - usually viral so not indicated except in severe infections, dysentery, young, old, immunocompromised
• may increase risk of haemolytic ureamic syndrome in E. coli
• ciprofloxacin covers most
• erythromycin for campylobacter
• metroniadazole for C. diff, entamoeba/giardia
Infection control - single room, own toilets; hand hygiene; avoid food prep; notify HPU
Antiemetics/antispasmodics
Things to consider in persistent diarrhoea
• Chronic GI infection eg cryptosporidium (?immunocompromised)
• GI malignancy
• Post-gastroenteritis lactose intolerance
• IBD
• IBS
People at risk of spreading GI infections
Food handlers, healthcare workers, children <5, older children and adults with a learning disability.
Outbreak definition
Diarrhoea and/or vomiting due to an infectious agent affecting two or more people thought to have a common exposure to a potential source e.g. ward environment.
OR
A rate of infection e.g. Clostridium difficile or illness above the expected rate for that place and time, where there is concern spread may be through cross infection or person-to-person
Measures to control outbreaks
• Gloves and aprons whilst handling affected patients or their environments
• Soap and water to wash hands, not alcohol sanitiser
• Separate toilet facilities
• Doors kept closed to affected bays/rooms
• Display appropriate signage when rooms, bays or wards are closed
• Isolate if possible, cohort if not
Cleaning
• Promptly clean areas of vomit or diarrhoea, before disinfecting with Difficil-s, and use Difficil-s on all surfaces nearby
• Increase environmental cleaning to twice daily
• Increase general cleaning, paying particular attention to high-touch areas
• Red bags for contaminated laundry
