6 Gastrointestinal Infections CONDITIONS Flashcards
Common oral infections list 7
- dental caries (tooth decay)
- gingivitis - inflammation of the gums
- periodontitis - inflammation of gums resulting in separation from teeth
- oral herpes - blisters on soft tissues
- oral thrush - fungal infection
- hand, foot and mouth disease
- herpangina
Causative agent of dental decay
streptococcus mutans
symptoms of dental decay.
- toothache
- tooth sensitivity
- grey, brown or black spots
- bad breath
- unpleasant taste
what is gingivitis ?
inflammation of the gums
causative agents of gingivitis
- Streptococcus mutans
- Actinomyces viscosus
- Veillonella species
symptoms of ginigivitis
- swollen or puffy gums
- gums that bleed easily
what is periodonitis?
inflammation of gums resulting in separation from teeth
causative agents of periodonitis
- Treponema denticola &
- Porphyromonas gingivalis
- Actinobacillus
actinomycetemcomitans
(juvenile periodontitis)
symptoms of periodonitis
- swollen or puffy gums
- bright red, dark red or dark purple
gums - pus between teeth and gums
- loose teeth or loss of teeth
- receding gums.
Causative agents of oral herpes
herpes simplex virus
oral herpes symptoms ?
- fever
- sore throat
- lymphadenopathy
- pain, burning, tingling, itching
- lip ulcer
- mouth ulcer
causative agents of oral thrush
Candida albicans
oral thrush symptoms ?
- white patches in mouth or on tongue
- cracks at the corners of the mouth
- altered sense of taste
- bad taste in mouth
- sore tongue or gums
causative agents of hand, foot & mouth disease
- Coxsackievirus A16 (CA16)
- Enterovirus 71 (EV71)
- Coxsackievirus A6 (CA6; adults)
symptoms of hand, foot & mouth disease
- sore throat
- fever
- not wanting to eat
- mouth ulcers
- raised rash of spots on hands & feet
(buttocks and genitalia)
causative agents of herpangina
- Coxsackievirus A16 (CA16)
- Coxsackievirus A serotypes
Coxsackievirus B (serotypes 1-5
symptoms of herpangina ?
- fever
- headache
- loss of appetite
- sore throat.
- sores or blisters (ulcers) in the mouth
and throat
Rotavirus:
1. family
2. RNA virus type
3. nucleocapsid shape
- reovirdidea
- non-enveloped ds segmented
- icosahedral
Rotavirus:
1. common infections (more so in who)
2. major cause of …
3. contagious status ? transmission method ?
4. incubation days
5. lasts days
- asymptomatic (breast-fed babies)
- diarrhoea in children
- highly contagious : faecal-oral
- 1-3
- 4-8
Rotavirus prevention of infection ?
2 live-attenuated vaccines (UK - Rotarix, EU, USA - Rotateq)
Vaccination routine for rotavirus in UK that was introduced in UK consists of what programme ?
2 doses :
one at 8 and 12 weeks of age
which cells of proximal small intestine can rotavirus infect? resulting in what ?
villus cells, replication with and lyses cells
Rotavirus infection :
…1… of carbohydrates and nutrients (so build up in lumen) . Vomiting followed by ..2.. (no ..3..) .
…4… and hospitalisation common in …5.. children
- imparied absorption
- diarrhoea
- blood
- dehydration
- young children
Diagnosis of rotavirus infection ?
EIA antigen in stool (infection can be established via genome amplification or ELISA)
management of rotavirus infection ?
primarily to overcome the effects of water and electrolyte imbalance
Symptoms of rotavirus infection principally induced by ?
viral enterotoxin NSP4
How are rotavirus infections treated ?
with oral rehydration or IV
Norovirus:
1. type of virus ?
2. nucleocapsid shape ?
- non-enveloped ss non-segmented RNA virus
- isochedra nucleocapsid
Ingestion of norovirus infection of food/water leads to ?
local infection and inflammation in proximal small intestine
Incubation & lasting period of norovirus
- incubtion = 24 - 48 hrs
- lasts = 12-60 hrs
Age population infected by norovirus
older children and adults
specificity and limitation of norovirus ?
non-specific, self-limiting
what outbreaks occur with norovirus ?
- large water-borne
- food-borne
- faecal-oral
Diagnosis and treatment of norovirus ?
diagnosis = no commercial tests
treatment = supportive (oral rehydration )
poliovirus family ?
what else does it include ?
picornaviridae
hepatitis A , enteroviruses
RNA virus type of poliovirus ?
non-enveloped single strand
What’s the potentially disbaling and life-threatening condition that poliovirus lead to ?
poliomyelitis
what will most people who get infected wtih poliobirus not have ?
any visible symptoms
About 1/4 people with poliovirus infection will have flu-like symptoms that includes what ?
- headache
- fever
- sore throat
- stomach pain
- nausea
- tiredness
flu-like symptoms that 1/4 people have usually lasts how long and then what happens ?
2 to 5 days
then resolve
watery diarrhoea bacterial gastroenteritis pathogens ?
305 salmon + Bats + Sheep (305 = CCCV)
Campulobacter jejuni
Clostridium difficle
Clostridium perfringens
vibrio cholera
salmonella spp
Bacillus ceres
Staphylococcus aurues
dysentery bacterial gastroenteritis pathogens ?
sick cats can’t sleep
Shighella spp
campylobacter spp
clostridium difficile
salmonella spp
which 2 bacteria can cause either watery diarrhoea or dysentery ?
clostridium difficile
salmonella spp
which E.coli strains results in watery diarrhoea ?
enteroxigenic & enteropathogenic
which E.coli strains result in dysentery ?
enteroinvasive & enterohaemorragic
Does yesernia enterocolitica result in watery diarrhoea or dysentery ?
dysentery
which vibrio result in :
1. watery diarrhoea
2. dysentery
- vibrio cholera
- vibrio parahaemolyticus
list some bacterial causes of gastroenteritis:
- clostridium difficile
- listeria monocytogenes
- campylobacter jejuni
- bacillus cereus
clostridium difficile risk factors
CHAPPIE 65
Certain medical conditions
History of C.diff infection
Antibiotic
PPI use or other acid-suppressive drugs
Prolonged hospitalisation / residence at nursing home
Immunocompromised
Exposure to infected persons
65 yrs < Age
What are the main toxins produced by Clostridium difficile and what are their effects?
A-enterotoxin
B-cytotoxin
What is the role of B-cytotoxin in Clostridium difficile infections?
cytotoxic to epithelial cells
leading to the formation of pseudomembranes
which are discrete yellow-white plaques that can be easily dislodged
How does A-enterotoxin produced by Clostridium difficile affect the body?
alters fluid secretion in the intestines, which causes watery diarrhea
Listeria monocytogenes is uncommon but ….?
underdiagnosed
Listeria monocytogenes risk factors ?
BIND > 65
Being pregnant
Immunosuppressed / immunocompromised
Newborn babies
Diabetes mellitus
> 65 years of age
sources of contamination of listeria monocytogenes ?
IF CUP
Food items:
* soft-cheese blue veined & mould-ripened e.g. camembert , brie
* pâté
Cooked:
* cooked sliced meats & cured meats
* cooked shellfish & smoked fish
Pre-prepared:
* sandwiches & salads
* some fruit including melon slices
Unpasteurised:
* milk
* dairy products from unpasteurised milk
campylobacter jejuni results from ingestion of ?
contaminated food/water
campylobacter jejuni symptoms may include ?
- diarrhoea (often bloody)
- Fever
- stomach cramps
- Nausea and vomiting
After person ingests Campylobacter:
1. symptoms usually start
2. symptoms last about
- 2 to 5 days after ingestion period
- one week
Transmission of campylobacter jejuni from ?
eating contaminated foods or untreated water e.g. poultry (raw or uncooked), seafood
What are the two syndromes caused by the ingestion of food contaminated with Bacillus cereus?
vomiting syndrome (emetic illness) and the diarrhoeal syndrome
What symptoms are associated with the vomiting syndrome (emetic illness) caused by Bacillus cereus?
vomiting, nausea, and diarrhea
What are the symptoms of the diarrhoeal syndrome caused by Bacillus cereus?
diarrhea (which can contain blood and/or mucus), nausea, and abdominal pain
How are the spores of Bacillus cereus characterized in terms of their resistance?
resistant to heat and desiccation (extreme drying)
What is the usual course of an infection caused by Bacillus cereus? meaning what ?
usually self-limiting therefore usually resolves on its own without requiring extensive medical treatment
From which sources can Bacillus cereus be isolated during an infection?
food, stool, or vomit
Where is Bacillus cereus commonly found?
soil, on vegetables, and in many raw and processed foods
List the helminthic infections that can cause gastrointestinal infections
- Nematodes (roundworms)
- Enterobius vermicularis (thread/pin worm)
- Trematodes (flukes)
- cestodes (tapeworms)
- Taenia spp. (flatworms cestoda)
Most common nematodes list 4 :
Trich Trich got long Ascar from a strong sterile hook
Trichuris Trichiura
Ascaris lumbricoides
Strongyloides sterocoralis
hookworms
Infections of nematodes (roundworms) include what ?
THE SAD FAT
Trichuriasis
Hookworm
Enterobiasis
Strongyloidiasis
Angiostrongyliasis
Dirofilariasis
Filariasis
Ascariasis
Trichinosis
Transmission for nematodes (roundworms) includes what ?
- ingestion of eggs that have matured in soil
- eggs hatch in soil and larvae penetrate skin directly
Treatment for nematodes (roundworms) ?
- cheap, effective and safe treatments available
- mass treatment programmes
Worm type of enterobius vermicularis ?
threadworm or pinworm
Enterobius vermicularis
1. is it common in UK?
2. age range affected ?
- yes
- children < 10 years
How are Enterobius vermicularis ova transferred to new hosts?
Ova are transferred from the perianal area to fomites, where they can survive for a long time. These ova can then be ingested by a new host
best way to remember = person using a towel to wipe perianal area then someone else using same towel to dry face
What is a common route of transmission for Enterobius vermicularis?
hand-to-mouth contact
Can Enterobius vermicularis cause auto-infestation?
auto-infestation = process by which organism becomes infested with parasites from its own species, individual may inadvertently reinfect themselves
Yes, auto-infestation can occur when individuals reinfect themselves by ingesting eggs from their own perianal area
What are some symptoms of Enterobius vermicularis infection?
perianal irritation
weight loss
bed-wetting
What are some common intermediate hosts for trematodes?
a range of intermediate hosts, including:
- other mammals
- freshwater snails
- possibly other organisms in their life cycle
What is the primary cause of inflammatory responses in humans infected with trematodes?
typically triggered by either the eggs or the adult worms of the trematodes
How many people globally are estimated to be infected with trematodes? give an estimate
40-50 million people
How are trematodes primarily transmitted to humans?
ingestion of contaminated food and water that contains or consists of the second intermediate hosts, such as vegetation, snails, and fish.
Name some common species of trematodes that infect humans
My heterophy heterophy echoes fast buses
- Metagonimus yokogawai
- Heterophyes heterophyes
- Echinostoma spp
- Fasciolopsis buski
What is the range of sizes for cestodes, or tapeworms?
few milimeters to several meters
How do tapeworms attach themselves to the intestines of their host?
To intestines of their host using suckers
What are proglottids, and where are they located on a tapeworm?
they are segments that arise from the anterior region of a tapeworm
They contain eggs and are shed from the mature tapeworm’s body.
How are tapeworm eggs typically released into the environment?
Faeces of host
What happens to eggs released by tapeworms ?
Egss released into faces and consumed by intermediate hosts, but eventually consumed by host (e.g. cattle pigs)
How do humans develop an infection usually of a single tapework ?
they consume undercooked meat
Why is it important to cook meat thoroughly to prevent tapeworm infection?
Cooking meat thoroughly kills the tapeworm larvae, preventing them from infecting humans who consume the meat
What are the common species of Taenia that infect humans through consumption of contaminated meat?
1. from beef
2. from pork
3. from fish
- Taenia saginata
- Taenia solium
- Diphyllobothrium latum
- How do pigs or cattle become infected with Taenia cysts?
- what hapeens to Taenia larvae after they are ingested by pigs or cattle ?
- ingestion of taenia cysts that are present in human faeces
- larvae develop in digestive system of pigs or cattle, the migrate to their muscle tissues where they encyst (surround itself in protective cyst/capsule)
How do humans become infected with Taenia larvae?
consuming meat or fish that contains Taenia larvae within cysts
What are the potential health consequences for humans infected with Taenia?
nutritional deficiencies
& intense infestations can lead to intestinal blockage.
What role do cysts play in the life cycle of Taenia?
They contain larvae which is essential for transmitting Taenia from intermediate hosts (e.g. pigs, cattle, fish) to humans
protozoal infections …
