diarrhoea infections/ incubation time Flashcards
pathogens that cause watery diarrhoea from releasing a toxin that enhances water and electrolyte secretion by enterocytes
o Vibrio cholerae o Enterotoxigenic E.coli o Clostridium perfringens o Staph aureus o Bacillus cereus
pathogens that destroy enterocytes causing diarrhoea with mucous/ blood pus fever and abdo cramps
o Shigella sp.
o Enterohaemorrhagic E.coli eg E.coli 0157
o Entamoeba histolytica
pathogens that disseminate beyong the GI tract causing fever and bacteraemia
salmonella
campylobacter and yersinia
how do pathogens disseminate from the gi tract
o Enterocytes invaded, multiplication in the macrophages/ mesenteric lymph nodes
4 patterns assoc. with diarrhoea infections
- Gastroenteritis like: diarrhoea and vomiting (fever)
- Diarrhoea with blood (+/- severe abdo pain)
- Dysentery: blood, pus, diarrhoea with mucous (fever) infection of the intestines resulting in severe diarrhoea with the presence of blood and mucus in the faeces.
- Watery “cholera like”: usually no fever
infective diarrhoea dx
> 3 stools a day
consider non infectious causes and diarrhoea causes outwith gi tract
causes of diarrhoea outwith gi tract
- septicaemia
- pyelonephritis
- legionellosis
campylobacter jejuni -found in -incubation stymptoms complications
o Undercooked poultry o Incubation period 1-3 days o Bloody stools, abdominal cramps, fever o Complication Bacteraemia Guillain- barre syndrome
non-typhoidal salmonella found in incubation symptoms complications
o Eggs (imported)/ poultry/ meats/ pets o Incubation period: 6-72 hours o D&V, high fever (no blood) o Complications Bacteraemia Aortitis Osteomyelitis Meningitis Splenic cyst o Typhoid usually presents with fever and constipation
what pathogen causes typhoid
salmonella typhi
what does vtec stand for
verocytotoxigenic E.coli
e.coli o157 and non-0157
vtec -reservoir symptoms diagnosis treatment
o Cattle and animals are reservoir
o Food eg (minced beef, raw vegetables, imported salad items, contaminated water, environment)
o Diarrhoea frequent, initially non bloody then bloody
o Haemolytic uraemic syndrome in 10-15%, usually aged <16 or >60
o Dx: culture or molecular tests (PCR)
o VTEC symptoms before HUS develops
81% diarrhoea
74% bloody diarrhoea
60% vomiting
56% abdo pain
23% fever
7% neurological
3% cardiomyopathy
treatment
-dont give antibiotics or anti motility drugs
4 types of shigella
- Shigella sonnei
- Shigella flexneri
- Shigella dysenteriae
- Shigella boydii
shigella
- symptoms
- who it affects and pathogens
- resistance to
- treatment
- Low infectious dose
- Causes dysentery and bloody diarrhoea
- Travellers eg returning from India/ Pakistan
- Other risk groups
o Young children
o Gay men=shigella flexneri - Fever/ vomiting/ abdo pain
- Increasing resistance to antibiotics especially ampicillin and cotrimoxazole
- Cephalosporins/ ciprofloxacin/ axithromycin active
what is the leading cause of bacterial diarrheas in tropical areas and travellers
entero-toxigenic E.coli
symptoms of entero-toxigenic e.coli
watery diarrhoea
vomiting
abdo cramps
mild or no fever
s. aureus
- incubation time
- transmission
- symptoms
- short incubation<4hrs
- asymptomatic carrier or a skin lesion
- contaminated ready to eat food
- vomiting and diarrhoea but no fever
bacillus cereus
- symptoms
- incubation
- reservoir
- how long incubation
-emetic and diarrhoeal
-watery diarrhoea
-presents in food and multiplies quickly if left at room temperature especially rice
self-limiting 24hrs
clostridium perfringens
- incubation
- symptoms
- reversvoir
- toxin generated in the gut after ingestion
- 6-24hrs
- abdo cramps, diarrhoea, no vomiting
- contaminated foods so usually seen in clusters eg one school
vibrio cholera
- type of bacteria
- where is it found
- reservoir
- which strain causes gastroenteritis rather than cholera
- gram negative bacilli
- india, central america, africa
- people and aquatic sources
- non-O1 strains cause gastroenteritis
clinical presentation of cholera and treatment
-diarrhoea
-watery diarrhoea
-dehydration
treatment
-tetracyclines
-rehydration
2 types of viral diarrhoea
- children-> rotavirus
- adult and children->norovirus
how are amoebiasis transmitted
orofaecal infections: cysts are eliminated in stools->ingested->trophozoites that invade the mucosal lining
presentation of amoebiasis
- asymptomatic 80%
- lose stools and abdo cramps
- +++blood stools and abdo cramps
- no fever-> colitis
