Diarrhoea Flashcards
define gastro-enteritis?
three or more loose stools/ day with accompanying features
define dysentery
large bowel inflammation with bloody stools
what is the most common foodborne pathogen?
campylobacter
Our defence against enteric infections?
stomach acidity,
normal gut flora,
Immunity
clinical feature of diarrhoeal illness
frequent watery stools with little abdo pain
causes of non-inflammatory diarrhoeal illness?
cholera,
enterotoxigenic E.coli
treatment of inflammatory diarrhoea?
rehydration therapy
Clinical features of inflammatory diarrhoeal illness?
mucosal destruction,
pain,
fever
Treatment of diarrhoeal illness?
antimicrobials,
rehydration
Questions to ask a patient with diarrhoea?
symptoms,
duration,
food poison risk eg diet, contact, travel
Key features to assess in a patient with diarrhoea?
hydration- postural BP, skin turgor, pulse
Inflammation features- fever, raised WCC
Define hyponatraemia and its cause
Low blood sodium due to sodium loss with fluid replacement by hypotonic solutions
Define hypokalaemia and its cause
loss blood K due to loos in stool
Investigations of a patient with diarrhoea?
stool culture, Ag testing, renal function, blood culture, blood count, abdominal Xray/ CT
DD of infectious diarrhoea?
IBD,
spurious diarrhoea,
carcinoma,
sepsis
GI presentation outside of gut?
diarrhoea,
fever,
lack of abdo pain/ tenderness,
no blood/ mucus in stools
why is dietary history in campylobacter gastroenteritis unreliable?
cambylobacter gastroenteritis has up to 7 days of incubation
Post-infection sequelae to campylobacter gastroenteritis?
Guillain-Barre syndrome,
Reactive arthritis
what are the 2 most common species od campylobacter likely to cause infection?
C.jejuni,
c.coli
Through what are you likely to be infected with campylobacter?
chickens,
contaminated milk,
puppies
after exposure to salmonella gastrienteritis how long till symptom onset?
<48hours
how long does diarrhoea last in salmonella gastroenteritis?
<10 days
What post-infection disease is common after a salmonella gastroenteritis infection?
post-infectious irritable bowel.
commonest isolates of salmonella causing infection in UK?
salmonella eneritidis,
salmonella typhimurium
How is E.coli o157 infection spread?
contaminated meat,
person-person spread
Characteristic presentation of e.colio157?
frequent bloody stools
what toxin does e.coli o157 produce?
shiga toxin
what disease is caused if shiga toxin gets into the blood?
hemolytic-uraemic syndrome
Presentation of hemolytic uraemic syndrome?
renal failure,
haemolytic anaemia,
thrombocytopenia
Treatment of e.coli o157 infection?
supportive
NOT antibiotics
why can e.coli o57 strain be distinguised from normal e.coli?
o157 is a non sorbitol fermenters
eating re-fried rice can cause food poisoning due to?
bacillus cereus
can staph aureus and clostridium perfringens cause food poisoning?
yes
when should you give a patient with gastroenteritis antibiotics?
immunocompromised,
severe sepsis,
invasive infection,
chronic illness
what toxins does c.diff produce?
enterotoxin,
cytotoxin
treatment for clostridiodes difficile diarrhoea?
metronidazole, oral vancomycin, fidaxomicin, stool transplant, surgery
the 4Cs associated with c.diff?
cephalosporins,
co-amoxiclav,
clindamycin,
ciprofloxacin
when do you give a patient with c.diff oral vancomycin?
if they have 2 or more severity markers
Investigations for diarrhoea caused by parasitology?
stool sample with P,C and O
main UK protozoa causing diarrhoea infection?
giardia duodenalis,
Cryptosporidium parvum,
Entamoeba histolytica
Presentation of giardia duodenalis infection?
Diarrhoea,
gas,
malabsorption,
failure to thrive
how are parasites transmitted?
direct contact with cattle, cats, dogs and other people,
food/ water contaminated with faeces
Investigations for giardia duodenalis?
Stool microscopy (will see cysts), Duodenal biopsy (will see trophozoites)
treatment of giardia duodenalis infection?
metronidazole
presentation of cryptosporidium parvum?
diarrhoea,
nausea,
vomiting,
abdo pain
Presentation of entamoeba histolytica?
amoebic dysentery,
invasive extraintestinal amoebiasis (live/pleuropulmonary/ brain abscess)
Investigations for entamoeba histolytica
stool microscopy,
antibody detection
Treatment for entamoeba histolytic infection?
metronidazole,
luminal agent to clear colonisation
what age group is rotavirus common?
under 5 years
Investigations of rotavirus?
antigen detection in stool
Investigation for diagnosis of noravirus?
PCR
Investigations for c.diff?
Temp (fever) WCC (increased) serum creatinine (increased) Serum lactate (increased) ELISA (detect A or B toxins)
Symptoms of mild and severe c.diff?
Mild: Moderate watery diarrhoea, Abdominal pain, Fever, Nausea
Severe: Watery diarrhoea up to 15 times daily, Blood in stool, Abdominal pain, Fever, Nausea, Dehydration
Complications of c.diff?
Pseudo-membranous colitis, Toxic megacolon, Perforation of colon, Sepsis, Death
What is the largest cause of traveller’s diarrhoea?
Enterotoxigenic e.coli
(gram -ve)
Transmission person to perosn and contaminated food and water
