INFECTIONS AND ENTEROCOLITIS Flashcards
1
Q
What is the most commonly accepted definition of diarrhoea?
A
> 3 loose stools in 24 hours
2
Q
What is osmotic diarrhoea?
A
This occurs when a soluble compound cannot be absorbed by the small intestine, and thus draws fluid into the intestinal lumen.
Examples include: osmotic laxatives; magnesium-based antacids; and foods containing mannitol, sorbitol, or xylitol. Osmotic diarrhoea can also be due to generalised malabsorption (for example, coeliac disease and pancreatic insufficiency).
The volume of diarrhoea is reduced by the absorption of fluid by ileum/colon so the diarrhoea stops when the pt stops eating or the malabsorption substance is discontinued
3
Q
What is secretory diarrhoea?
A
results from increased secretion of fluid and electrolytes into the intestine alongside decreased absorption
Can be caused by infections, fatty acids, bile salts and some drugs
Even if the person fasts, secretory diarrhoea will persist
4
Q
What is inflammatory diarrhoea?
A
Damage to intestinal mucosal cells affects absorption of fluid and electrolytes and results in fluid and blood loss. Infection (e.g. Shigella) and conditions such as ulcerative colitis and Crohn’s disease are causes of inflammatory diarrhoea.
Nocturnal symptoms are often present.
5
Q
Outline how increased intestinal motility can cause diarrhoea?
A
This may present with an increased frequency of stool passage without an increase in volume. It can occur with endocrine conditions such as diabetes and hyperthyroidism.
6
Q
What are the possible mechanisms that can cause diarrhoea?
A
Increased osmotic load in the gut lumen
Increase in secretion
Inflammation of intestinal lining
Increased intestinal motility
7
Q
Whats acute and chronic diarrhoea?
A
Acute lasts <14 days
Persistant lasts >2 weeks but <4 weeks
Chronic lasts >4 weeks
8
Q
What typically causes acute diarrhoea?
A
Infections
9
Q
What are some common infectious causes of diarrhoea?
A
Viral - norovirus or rotavirus
E.coli food poisoning
Food poisoning from salmonella, campylobacter or staphylococcus bacteria
C.diff infections
Contaminated food or water - typically giardia or entamoeba histolytica
10
Q
What are the clinical features of infectious diarrhoea?
A
Fever
Abdominal pain
Vomiting
Acute diarrhoea
(Dehydration my occur especially in very young or elderly patients)
11
Q
What are the key investigations for infectious diarrhoea?
A
Stool microscopy culture sensitivities
Samples for c.diff toxin in some cases
Stool for ova, cysts and parasites in some cases
12
Q
In which people with infectious diarrhoea should you test stool sample for c.diff toxins?
A
Elderly
Nursing home residents
Recent antibiotic use
13
Q
In which people with infectious diarrhoea should you test stool sample for ova, cysts and parasites?
A
Persistent diarrhoea
Men who have sex with men
Immunocompromised patients
Recent travel abroad
If suspecting giardiasis, amoebas is or cryptosporidium
14
Q
How is acute diarrhoea managed?
A
Volume depletion with oral rehydration solutions or in serious cases IV fluid resuscitation
In some cases antibiotic treatment may be indicated
15
Q
When is antibiotic treatment indicated for acute diarrhoea?
A
Severe/prolonged sympotms e.g. >5 days
Systemic signs of infection
Extremes of age
Immunocompromised individuals
Complications
Bloody or mucoid stools
16
Q
What are the causes of chronic diarrhoea?
A
IBS
Microscopic colitis
IBD
Colonic cancer
Medications
Diet
Bile acid diarrhoea
Pancreatic insufficiency
Coeliac disease
Overflow diarrhoea
Others e.g. hyperthyroidism, radiation enteritis, incontinence, SIBO etc
17
Q
What investigations should be done for chronic diarrhoea?
A
FBC, U&Es, TFTs
Coeliac screen - TTG or EMA antibodies
Faecal calprotectin
Stool MCS and c.diff toxin screen
If the above dont reveal a cause then patients should undergo a flexible sigmoidoscopy or colonoscopy
Further investigations dependant on sympotms include… imaging, SeHCAT scan, lactose hydrogen breath test
18
Q
What are considered normal bowel habits?
A
Vary on an individual basis but it is generally considered normal once every 3 days to 3 times a day
19
Q
What is dysentery?
A
an infection of the intestines that causes diarrhoea containing blood and sometimes mucus
20
Q
What can cause osmotic diarrhoea?
A
Disaccharide deficiencies
Drug-induced
Galactose
Generalised malabsorption
21
Q
What can cause secretory diarrhoea?
A
Infections
Defects in intraluminal digestion and absorption
Excess laxative use
22
Q
Outline how increased AND decreased gut motility can lead to diarrhoea?
A
Increased - lack of absorption due to rapid transit
Stasis - facilitates bacterial overgrowth which can cause diarrhoea
23
Q
What can cause bloody diarrhoea?
A
Inflammation - IBD
Infection
Neoplasms
24
Q
What is enterocolitis?
A
Inflammation of the intestines
25
Why has there been improved prevalence of infectious enterocolitis in the developed world?
Due to improved sanitation
26
What are the types of enterocolitis?
Infectious enterocolitis
Necrotising enterocolitis
Pseudomembranous colitis
Ulcerative colitis
Ischaemic colitis
Microscopic colitis
Allergic colitis in infants
27
Whats are the types of infectious enterocolitis?
Viral gastroenteritis
Bacterial enterocolitis
28
What is gastroenteritis?
Inflammation of the stomach and intestines
a transient disorder due to enteric infection with viruses, bacteria, or parasites. It is characterized by the sudden onset of diarrhoea, with or without vomiting
29
Whats the most common form of acute GI infection?
Gastroenteritis
30
Is viral or bacterial gastroenteritis more common?
Viral and so if often self limiting
31
What is food poisoning?
an illness caused by the consumption of food or water contaminated with bacteria and/or their toxins, or with parasites, viruses, or chemicals
32
What is travellers diarrhoea?
involves travel from high-income to lower- and middle-income countries and is defined as diarrhoea developing at the destination with at least one additional symptom, such as abdominal cramps, tenesmus, nausea, vomiting, fever, or faecal urgency
33
What is an outbreak defined as?
two or more cases associated in time and place
34
Outline the epidemiology of gastroenteritis?
Affects 1 in 5 people in the UK each year - common but deaths attributed to it is rare i.e. only 1 in 30 present to healthcare services
One of the leading causes of death in children under 5 in resource-limited countries
35
What proportion of cases of gastroenteritis will last <24 hours?
Up to 50%
36
How is gastroenteritis transmitted?
Faecal-oral
Food borne
Airborne e.g. vomiting
Environmental e.g. contaminated surfaces
37
Which bacteria are commonly implicated in food-borne gastroenteritis due to enterotoxins?
Staph aureus - enterotoxin B
Bacillus cereus
Clostridium perfringens type A
Vibrio cholera’s
Salmonella spp
Campylobacter spp
ETEC
38
How is food-borne gastroenteritis ‘food poisoning’ transmitted?
Primarily caused by enterotoxins produced by the microorganism rather than the microorganism itself
They produce a rapid onset after ingestion of food and typically last for <24 hours
39
Whats the cause of traveller’s diarrhoea?
In up to 70% of cases no specific causative agent is identified
The risk of this depends on destination, duration of exposure and host factors
40
What are common viruses that cause gastroenteritis?
Rotavirus
Norovirus
Adenovirus
41
What are the typical bacterial causes of watery diarrhoea?
C.diff
Clostridium perfringens
Enterotoxigenic E.coli (ETEC)
42
What are the typical bacterial causes of bloody diarrhoea?
Non-typhoidal salmonellosis
Campylobacter spp.
Shigella spp.
Yersinia enterocolitica
Enterohaemorrhagic E.coli (EHEC)
43
Whats the most common cause of viral gastroenteritis in children?
Rotavirus - prevalence decreasing due to introduction of rotavirus vaccine
Infection in adults is uncommon because immunity is long lasting
44
Whats the commonest cause of gastroenteritis in England and Wales?
Norovirus
Infection can occur in people of all ages because immunity is not long lasting
45
When does Norovirus prevalence increase in prevalence?
In colder months
46
What are the most commonly reported bacterial causes of infectious intestinal disease in England and wales?
Campylobacter spp.
47
How is rotavirus transmitted?
Most cases are transmitted by person-to-person spread by the faecal-oral route, or more rarely by contact with contaminated surfaces
48
What are symptoms of rotavirus?
watery diarrhoea and vomiting with or without fever and abdominal pain.
Vomiting usually settles within 1–3 days, and diarrhoea within 5–7 days, but can persist for 2 weeks.
49
How does Norovirus present?
Symptoms begin 24–48 hours after infection and last for 12–60 hours.
Sudden-onset nausea is followed by projectile vomiting and watery diarrhoea.
There may be associated fever, headache, abdominal pain, and myalgia.
Most people make a full recovery within 1–2 days.
50
How is Norovirus transmitted?
Faecal-oral route - person to person, or contaminated food/water or contact with contaminated surfaces
Outbreaks are common in semi-closed environments e.g. cruise ships, schools, hospitals
51
How does infection with campylobacter spp present?
Asymptomatic in 25-50%
Diarrhoea which may be bloody, nausea, vomiting, abdominal cramps and fever
Self-limiting mostly within 2-3 days and usually resolve within 1 week
52
How is campylobacter jejuni and campylobacter coli transmitted?
Consumption of contaminated food and drinks - undercooked meat (especially poultry), unpasteurised milk, untreated water
53
Whats the most commonly identified shiga toxin-producing E.coli in the UK?
E.coli 0157
54
Which groups of people does infection with E.coli 0157 affect?
Children under 5
Peak incidence in children 1-4
55
How does infection with E.coli 0157 present?
May be asymptomatic
Diarrhoea (may be bloody), fever, abdominal cramps, vomiitng
Self-limiting usually and resolved in 10 days
56
How is E.coli typically transmitted?
Through contaminated food - meat, salad products, water and unpasteurised milk
Faecal-oral route
Contact with infected animals - cattle, sheep, goats
Environmental exposure to contaminated water
57
What are the features of infection with salmonellosis?
Water and sometimes blood diarrhoea
Abdominal pain
Headache
Nausea
Vomiting
Fever
Illness usually starts within 3 days of exposure and resolves within a week
58
How is salmonellosis transmitted?
Contaminated food ingestion (most common) - red and white meats, raw eggs, milk, dairy products
Faecal oral
Contact with infected animals
59
How is shigellosis transmitted?
Faecal-oral route
More rarely - contaminated food or sexual transmission (men who have sex with men)
60
What age does shigellosis tend to affect? What time of year?
Children <5 most commonly but can occur at any age
Infections peak laste summer
61
How does shigellosis tend to present?
1-3 days after infection there is diarrhoea which may have blood and mucus. There is also fever, abdominal cramps, nausea, vomiting, headache and malaise
It typically resolves in 5-7 days
62
How common is gastroenteritis caused by yersinia enterocolitica? Who is most likely to get it?
Rare!
Children
63
How does infection with yersinia enterocolitica present?
Symptoms develop4-7 days after exposure and may last 2 days-6 weeks
Watery diarrhoa which is often bloody
Fever and abdominal pain
Lymphadenopathy
In older children or adults it can cause mesenteric lymphadenitis which causes RLQ abdominal pain which can give the impression of appendicitis
64
How is yersinia enterocolitica typically transmitted?
Direct contact with infected animals
Faecal-oral
Contaminated food and water - particularly pork products
65
Which group of people are more likely to get gastroenteritis secondary to parasites?
Travellers/foreign travel
66
What are the most common parasitic causes of gastroenteritis?
Cryptosporidiosis
Entamoeba histolytica
Giardia intestinalis or giardia lamblia
67
Whats the most commonly identified pathogen in prolonged travellers diarrhoea?
Giardia spp
68
How is cryptosporidiosis transmited?
Animal to human
Human to human - contaminated land or water, food
69
How does gastroenteritis secondary to cryptosporidiosis present?
Profuse eatery diarrhoea with abdominal cramps/pain, nausea, vomiting, fever, loss of appetite
Symptoms usually last 1-2 weeks
Note: recurrence of symptoms is reported in 1/3rd of cases
70
How does entamoeba histolytica transmit?
Ingestion of contaminated food or water
Faecal oral route
71
How does gastroenteritis secondary to entamoeba histolytica present?
90% asymptomatic
Symptoms are often mild diarrhoea and abdominal pain
But amoebic dysentery (severe disease) can occur causing fever, abdo pain, blood and mucus in diarrhoea
72
How is giardiasis transmitted?
Faecal-oral
Faeces of infected animals
Consumption of food or drink
Sexual transmission, especially amongst men who have sex with men
Increased risk of transfer in swimming pools
73
What are the symptoms of giardiasis?
Diarrhoea
Malaise
Abdominal pain
Loss of appetite
Flatuence
Bloating
Nausea
Children may experience malabsorption, weight loss, faltering growth
74
What type of virus is rotavirus?
A double stranded RNA virus
75
What type of virus is norovirus?
Single stranded RNA virus
76
What complications has infection with campylobacter been linked to?
Autoimmune conditions = reactive arthritis, Guillain-Barre syndrome
77
What type of bacteria is salmonella?
Gram negative
Rod shape - bacilli
78
What are the 2 salmonella species?
Enterica
Bongori
79
What are salmonella enterica subspecies?
Spp enterica
Spp Salamae
App arizonae
Spp diarizonae
Spp houtenae
Spp indica
80
What are the important serotypes of salmonella enterica subsp. enterica?
Salmonella enteritidis - cause of gastroenteritis
Salmonella typhimurium - cause of gastroenteritis
Salmonella typhi - cause of typhoid fever
Salmonella paratyphi - cause of paratyphoid fever
81
What are the intestinal strains of E.coli?
Enteropathogenic E.coli (EPEC)
Enterohaemorrhagic E.coli (EHEC)
Enteroinvasive E.coli (EIEC)
Enterotoxogenic E.coli (ETEC)
82
What is Enterohaemorrhagic E.coli also known as?
Shigatoxigenic E.coli because it produces a shiga-toxin
83
Whats the most common stereotype of EHEC that commonly causes bloody diarrhoea illness in infants?
E.coli 0157
84
What are the important complications of infection with EHEC 0157?
Can cause haemolytic uraemic syndrome in up to 20% of infected children and accounts for 90% of cases of HUS in children
85
What is haemolytic uraemic syndrome characterised by?
Microangiopathic haemolytic anaemia
Thrombocytopenia
AKI
86
What are the symptoms and signs of general gastroenteritis?
Diarrhoea - watery, bloody, mucois
Nausea and vomiting
Fever
Abdominal pain
General malaise
Bloating and cramping
Weight loss
Features of dehydration e.g. poor cap refill, dry mucous membranes, poor feeding, irritability, poor urine output, altered mental state
Features of shock - tachycardia, hypotension
87
If you suspect gastroenteritis, what risk factors should you ask about?
Occupation - food handler, healthcare worked, nursery worker
Recent food intake - BBQ, restaurant, takeaway
Recent exposure to untreated or potentially contaminated water
Contact with other affected individuals
Recent foreign travel
Recent antibiotic or PPI use (C.diff risk)
Recent hopsital admission (C.diff risk)
88
How should you investigate gastroenteritis?
Examine for clinical features of dehydration, shock, sepsis, abdomen, weight and signs of malnutrition
Stool culture and sensitivity sometimes
Stool test for ova, cysts and parasites (3 specimens 2-3 days apart) sometimes
Blood tests are not routine but can be useful to assess for complications e.g. AKI or HUS
Imaging is not routinely done
89
What are the indications for stool culture and sensitivity for those presenting with acute diarrhoea?
If person is systemically unwell or immune compromised
Suspecting dysentery e..g acute painful diarrhoea or blood, mucus and or pus in stool
Suspecting c.diff - recent antibiotic, PPI use or hopsital admission
If diarrhoea hasn’t resolved by day 7
If suspected food poisoning
If recent travel
If person is at risk of transmission e.g food handler, nursery staff, unable to perform adequate personal hygiene due to lack of capacity, all children before 6th birthday who attend childcare
In an outbreak
If uncertainty about diagnosis
90
What are the indications for checking stool for ova’s, cysts and parasites?
If recent travel to anywhere other than Western Europe, North America, Australia or New Zealand
If diarrhoea is recurrent or prolonged >14 days
91
What are the clinical features that suggest mild dehydration in adults?
Lassitude/fatigue
Anorexia
Nausea
Light-headidness
Possible postural hypotension
92
What are the clinical features that suggest moderate dehydration in adults?
Tiredness
Dizziness
Nausea
Headache
Msucle cramps
Pinched face
Dry tongue or sunken eyes
Reduced skin elasticity
Postural hypotension
Tachycardia
Oliguria
93
What are the clinical features that suggest severe dehydration in adults?
Profound apathy and weakness
Confusion leading to coma
Marked peripheral vasoconstriction
Hypotension
Tachycardia
Uraemia, oliguria or anuria
Shock
94
What are differential diagnoses for gastroenteritis?
UTI
Pyelonephritis
Chest infection
Otis media
Sepsis
IBS
IBD
Colorectal cancer
Hirschsprungs enterocolitis
Short bowel syndrome
Food-sensitive enteropathy
Coeliac disease
Constipation with overflow
Diabetes ,mellitus
Hyperthyroidism
Congenital adrenal hyperplasia
Addisons disease
Hypoparathyroidism
HIV and AIDS
Secretory tumours
Drugs - antibiotics, antimalarials, magnesium-containing antacids, antimotility drugs, laxative misuse
95
What are the indications for arranging emergency hospital admission for an adult with gastroenteritis?
Person systemically unwell
Clinical features suggesting severe dehydration and/or progression to shock
Intractable vomiting or high-output diarrhoa
Suspected serious complications e.g. sepsis
96
How should you manage an adult with gastroenteritis in primary care?
Encourage regular fluid intake or use of oral rehydration salt solutions for those at increased risk of dehydration
Antidiraahoes, antiemetics, probiotics should not be recommended routinely
Do not routinely prescribe antibiotics - arrange treatment of confirmed microbial pathogens if appropriate
Advise on methods to prevent transmission of infection
Advise that person should not attend work or other social settings until at least 48 hours after the last episode of D+V
97
What advice should you give a patient on methods to prevent transmission of infection?
Wash hands thoroughly with liquid soap and warm running water
Always flush toilet
Clean toilet seats, flush handle, taps etc once a day with hot water and detergent
Dont share towel and flannels
Wash soiled clothing and bed linen separately from other clothes at a high temperature
PHE leaflet
98
When should you notify the local health protection team with a case of gastroenteritis?
If any of the following notifiable disease or organisms are suspected:
Food poisoning
HUS
Infectious bloody diarrhoea e.g. shigella spp
Enteric fever
Cholera
Bacillus cereus if due to food poisoning
Campylobacter spp
Clostridium perfringens if due to food poisoning
Cryptosporidium spp
Entamoeba histolytica
Giardia lamblia
Salmonella spp
Shigella spp
99
If the confirmed microbiological cause of gastroenteritis is campylobacteriosis, how should you manage it?
Antibiotics are not usually needed as symptoms are often mild and infection is self limited
If synmptoms are severe or person is immunocompromised, consider early prescribing with clarithromycin 250-500mg twice daily for 5-7 days, within 3 days of onset of illness
100
If the confirmed microbiological cause of gastroenteritis is cryptosporidiosis, how should you manage it?
No specific treatment licensed in the UK so seek specialist advise if person is severely immunocompromised
101
If the confirmed microbiological cause of gastroenteritis is amoebiasis, how should you manage it?
Drug treatment is recommended for all confirmed cases - metronidazole followed by the anti-protozoal drug diloxanide
102
If the confirmed microbiological cause of gastroenteritis is E.coli, how should you manage it?
No effective treatment
Seek specialist advise for monitoring for HUS
103
If you had gastroenteritis caused by STEC, when can you return to work or other social settings?
two consecutive negative stool samples are usually needed taken at least 24 hours apart, once the person is symptom free for at least 48 hours, before the person can return to work or other institutional/social settings.
104
If the confirmed microbiological cause of gastroenteritis is giardiasis, how should you manage it?
Prescribe tinidazole 2g as a single dose
105
If the confirmed microbiological cause of gastroenteritis is salmonella spp, how should you manage it?
Antibiotic treatment is not usually needed
106
If the confirmed microbiological cause of gastroenteritis is shigella, how should you manage it?
Antibiotic treatment is not usually needed for mild symptoms
If symptoms ar severe then seek specialist advise
Advise on safe sexual practices if transmission amongst men who have sex with men resulted in an outbreak
107
What are the complications of gastroenteritis?
Dehydration
Electrolyte disturbance
AKI
Haemorrhagic colitis - from STEC
HUS - from STEC 0157, shigella dysenteriae or campylobacter spp
TTP - from STEC
Reactive arthritis - campylobacter spp, shigella flexneri, yersinia enterocolitica
Aortitis and osteomyelitis - salmonella spp and yersinia spp
Sepsis - salmonella spp and yersinia enterocolitica
Toxic megacolon
Pancreatitis, sclerosing cholangitis and liver cirrhosis - cryptosporidium spp
Faltering growth - Giardia spp
Chronic intractable diarrhoea - viral, Giardia spp, cryptosporidium spp
Post-infectious IBS
IBD - non-typhoidal salmonella, campylobacter spp, c.diff
Acquired or secondary lactose intolerance - up to 40% after giardiasis
Guillain-Barré syndrome - virus and campylobacter spp
Meningitis - salmonella (particularly infant s<3 months!!)
Invasive entamoeba infection i.e. extra intestinal infection when entamoeba histolytica invades the liver causes abscesses which can be life threatening
108
What is dioralyte?
Potassium chloride with rice powder, sodium chloride and sodium citrate
1 sachet can be reconstituted in 200ml of water
109
How much reconstituted liquid should be given for every loose stool motion
200-400ml
110
Whats the risk of using quinolones in pt with gastroenteritis secondary to shigella spp or EHEC 0157?
Increased risk of HUS
111
Why should antidiarrhoeal agents be avoided in dysentery or confirmed cases of shigella spp or EHEC?
Increased risk of toxic colonic dilatation
112
What proportion of pt with gastroenteritis will have post-infectious IBS?
10%
113
What are the risk factors for developing post-infectious IBS?
Female sex
Young age
Prolonged fever
Anxiety and depression
114
What are the pathogenic mechanisms of bacterial gastroenteritis?
Mucosal adherence - causes moderate watery diarrhoea
Mucosal invasion - causes dysentery
Enterotoxins production - fluid secretion without mucosal damage so profuse watery diarrhoea
Cytotoxic production - damage to mucosa so causes dysentery
115
Which bacteria are commonly implicated in food-borne gastroenteritis due to cytotoxins?
Salmonella spp
Campylobacter spp
EHEC 0157
E.coli O104:H4
116
Which bacteria typically cause dysentery?
Shigella spp
Campylobacter spp
EIEC
Salmonella spp
EHEC
E.coli O104:H4
117
When is antibiotic therapy always needed in cases of gastroenteritis?
Dysentery in children - proven to reduce mortality
118
Whats the incubation period for rotavirus?
1-3 days
119
Whats the incubation period for norovirus?
1-2 days
120
Whats the incubation period for adenovirus?
3-10 days
121
Whats the incubation period for salmonella?
6-72 hours
122
Whats the incubation period for campylobacter?
2-5 days
123
Whats the incubation period for shigellosis?
12-96 hours
124
Whats the incubation period for Giardia?
1-2 weeks
125
Whats the incubation period for cryptosporidium?
2-10 days
126
Whats the incubation period for E.coli?
3-8 days
127
What are the most common causes of acute food poisoning?
Staph aureus (1-6 hours)
Bacillus cereus (1-6 hours)
Clostridium perfringens (6-12 hours)
128
Whats the incubation period for a diarrhoea and vomiting subtypes of bacillus cereus?
Diarrhoea - 1-6 hours
Vomiting 6-14 hours
129
How is norovirus spread?
Faecal oral
Maybe also through direct contact
130
How is rotavirus spread?
Faecal-oral
Maybe also resp
131
How is adenovirus spread?
Direct contact
Faecal oral
Maybe water
132
How is campylobacter spread?
Undercooked poultry
Seafood
Dairy products
Animal contact
Untreated water
133
How is E.coli spread?
Undercooked meat (most often contaminated ground beef)
Unpasteurised milk
Contaminated raw veg
134
How is salmonella spread?
Faecal oral
Food e.g. raw poultry (94% of cases)
Water
Direct animal contact
Rarely from person to person
135
How is bacillus cereus spread?
Food contaminated with enterotoxigenic B or emetic toxin
E.g. rice, potatoes, beans, peas
136
How is clostridium perfringens spread?
Food - meat, poultry, fish, gravy, veg and other foods cooked in large batches and held at unsafe temperatures
137
How is Giardia spread?
Faecal-oral
Giardia lamblia is a microscopic parasite that lives in small intestines of mammals e.g. humans, pets, farmyard animals. It releases cysts in the stools of infected mammals
138
How is shigella spread?
Faecal-oral
139
How is cholera spread?
Faecal-oral
140
How is cryptosporidium spread?
Faecal-oral, direct contact, contaminated food and water
141
What is enteric fever?
Typhoid and paratyphoid
Diseases caused by salmonella typhi and salmonella paratyphi respectively they produce systemic sympotms like headache, fever and arthralgia
Transmitted via faecal-oral route
142
What is pseudomembranous colitis?
Inflammation of the colon due to an overgrowth of c.diff
143
Whats the difference between gastritis, enteritis, gastroenteritis?
Acute gastritis is inflammation of the stomach and presents with nausea and vomiting.
Enteritis is inflammation of the intestines and presents with diarrhoea.
Gastroenteritis is inflammation all the way from the stomach to the intestines and presents with nausea, vomiting and diarrhoea.
144
Why can E.coli 0157 cause haemolytic uraemic syndrome?
As the shiga toxin can destroy blood cells
145
What are the symptoms of E.coli 0157?
Abdominal cramps
Bloody diarrhoea
Vomiting
146
Why can shigella cause HUS?
It can produce shiga toxin which can destroy RBC
147
What are the symptoms of campylobacter jejuni?
Abdo cramps
Diarrhoea often with blood
Vomiting
Fever
148
What are the symptoms of shigella?
Bloody diarrhoea
Abdominal cramps
Fever
149
What are the symptoms of salmonella?
Watery diarrhoea which may be associated with mucus or blood
Abdominal pain
Vomiting
150
Whats the most common cause of bacillus cereus ingestion and outline the pathology?
Fried rice left out at room temperature
Whilst growing on food it produces a toxin Called cereulide which causes abdominal cramping and vomiting within 5 hours of ingestion
When it arrives in the intestine it produces different toxins which cause watery diarrhoea >8 hours after ingestion
All symptoms will resolve within 24 hours
151
Whats the clinical picture of gastroenteritis caused by bacillus cereus?
Vomiting within 5 hours
Diarrhoea after 8 hours
Resolution within 24 hours
152
Whats the incubation period of yersinia enterocolitica?
4-7 days
153
How is staph aureus spread?
It can produce enterotoxins when growing on foods such as eggs, dairy and meat - these toxins cause small intestine inflammation
154
Whats the pathophysiology of enterotoxigenic and enteropathy genie e.coli causing gastroenteritis
Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen
Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate invasive component produces enteritis and large volume diarrhoea together with fever.
155
Why is there an increased risk of transfer of Giardia in swimming pools?
Due to resistance to chlorination
156
How does giardia present?
Diarrhoea
Flatulance
Steatorrhoea
Stomach cramps
Nausea
157
Whats the most common cause of gastroenteritis on a cruise?
Norovirus
158
What would make you suspect rotavirus as a cause of gastroenteritis?
If it was in children!
159
What should you wait for before giving antidiarrhoeals?
Stool culture results
