Infection Summary Flashcards
Gastroenteritis Presentation
vomiting and diarrhoea (3 or more loose stools a day), + abdominal pain/discomfort (can be quite severe if campylobacter), fever,
bloods in stool can be indicative of a bacterial infection
signs of dehydration:
thirsty, dry mucous membranes: mild, (<5% weight loss)
lethargic, reduced skin turgor, sunken eyes, sunken anterior fontanelle, tachycardia, reduced urine output, reduced tears: moderate (5-10% weight loss)
drowsy, absent urine output, prolonged capillary refill time, weak pulse, low BP (signs of hypovolaemic shock): severe (>10% weight loss)
Gastroenteritis Investigation / diagnosis
stool MC&S, urea and electrolytes
Gastroenteritis Management
oral rehydration therapy given frequently in small amounts; IV fluids if not tolerating oral/nasogastric fluids. Good handwashing to prevent spread. Notify public health if bacterial
Complications of campylobacter infection
Guillain-Barre
Reactive arthritis
What can predispose you to gastroenteritis?
HIV
Omeprazole
Presentation of CDIFF
mild diarrhoea to severe colitis
diarrhoea, fever, abdominal pain
Investigations for CDIFF
stools MC&S, FBC (increased WCC)
Treatment for C. Diff
metronidazole (first line), stool transplant, oral vancomycin (second line), fidaxomicin, surgery may be required, isolation, barrier nursing
prevention: stop AB (cephalosporin, clarithromycin, clindamycin, co-amoxiclav) (fluoroquinolones are also important in the development of c.diff)
Pass medicine note: Clindamycin is historically associated with causing Clostridium difficile but the aetiology has evolved significantly over the past 10 years. Second and third generation cephalosporins are now the leading cause of Clostridium difficile.
What are the complications of C.Diff?
pseudomembranous colitis, toxic megacolon, sepsis
What are the toxins that c.diff produces?
A (enterotoxin) and B (cytotoxin)
Presentation of infectious diarrhoea
fever, diarrhoea (may be bloody), nausea, dehydration, abdominal pain, bloody diarrhoea is more common with Campylobacter, Shigella
What is the diagnosis of infectious diarrhoea?
diagnosis by antigen detection
FBC, U&E, CRP, stool microscopy, culture and sensitivity (MC&S), blood cultures if septic
What is the management of infectious diarrhoea?
majority of cases are self-terminating and require rehydration and electrolyte correction: AB are considered in immunocompromised patients, the very young or the very septic; always liaise with microbiologists
What viruses can cause infectious diarrhoea?
adenovirus, rotavirus in children under 5 years
What are the complications of infectous diarrhoea?
renal failure, septic shock; E. coli is associated with the haemolytic-uraemic syndrome
What are the symptoms / presentation for giardia lamblia?
diarrhoea, malabsorption, failure to thrive
Giardiasis:
a patient develops persistent foul-smelling watery diarrhoea and weight loss after travelling to India. His symptoms have now lasted two weeks. He has no abdominal pain, nausea or fever
What is the investagation for giardia lamblia?
Cysts seen on stool microscopy
What is the treatment for giardia lamblia?
Metronidazole
How is giardia lamblia spread?
Contaminated water
Whet type of organism is giardia lamblia?
Parasite
What bacterium causes the majority of cases of travellers diarrhoea in developing countries?
Enterotoxigenic e.coli
What is the normal reservoir of Ecoli o157 (this is an enterohaemorrhagic bacterium)
2.5% of britich cattle secrete VTEC (verotoxin producing Ecoli)
The reservoir of infectio nis in the gut of herbivores.
The organism has an ectremely low infecting dose.
What are the symptoms of enterohaemorrhagi bacteria?
Initial watery diarrhoea
Becomes blood stained in 70% of cases. Associated with severe and often constant abdominal pain.
Little systemic upset, vomittin or fever.
What is the complication associated with Ecoli o157?
HUS
Haemolytic Uraemic syndrome



