Gastrointestinal Infections Flashcards
List the common symptoms of acute gastroenteritis
Diarrhoea
Nausea and vomiting
Abdominal pain
Fever
List the clinical syndromes of gastroenteritis
Acute gastroenteritis Dysentery (blood in diarrhoea) Traveller’s diarrhoea Post antibiotic diarrhoea Chronic diarrhoea >2-3 weeks
Name the bacteria normally associated with gastroenteritis, from most to least popular
Campylobacter Salmonella Shigella Escherichia coli E.coli 0157 Clostridium difficile
Name the common viruses known to cause gastroenteritis
Norovirus
Rotavirus
Adenovirus
Name the common Protozoa in gastroenteritis
Cryptosporidium
Giardia lambila
Entamoeba histolytica
What must happen for dysentery to occurs
What pathogen does not cause dysentery
Need to damage mucosa
Virus and cryptosporidium can’t cause dysentery
What bacteria is not relevant in travellers diarrhoea
C.diff
The more c.diff that is found, the greater the
Damage to the mucosa
What do you find with chronic diarrhoea
Likely to come from travellers diarrhoea from parasites
Post-infection syndromes can be irritable bowel or malabsorption
What are the differential diagnosis with gastroenteritis
As you get older, more complications can happen so you need to determine if it is contagious
Inflammatory bowel disease Diverticula disease Ischaemic colitis Colorectal carcinoma Malabsorption Pneumonia
If someone presents with diarrhoea, what should you do?
Take a stool sample
Microscopy (cysts, parasites (OCP for particular parasite))
And culture
Check for rotavirus or c.diff
More so in hospital than in general practice if ill enough
May have to get more than one specimen if need more parasites numbers
Sometimes need to do a colonoscopy
List the general management for diarrhoea
Oral or IV rehydrates Analgesia Antiemetics (ondansetron) Avoid antidiarrhoeal agents (loperamide), e.g. dysentery in children Isolation in hospital Notification to public health Return to work or school
Example of giving an antibiotic in diarrhoea symptom
Suspected c.diff diarrhoea - metronidazole or vancomycin
Travellers diarrhoea <80% due to bacteria, more likely to make a difference
If due to parasites, confirm on stool, chronic symptoms and no response to ciprofloxacin
There’s controversial area for antibiotics being used for acute gastroenteritis
Risk of using antibiotic therapy in gastroenteritis
Prolong the duration of carriage (salmonella)
Antibiotic-associated diarrhoea
Antibiotic resistance
Adverse drug events
Is the incidence of symptomatic UTIs get older with age?
Yes because decrease of oestrogen, affects bacteria a and mucosal area, those bacteria can win the numbers in the environment
Asymptomatic bacteriuria
Truest asymptomatic
Don’t need to do anything
Institutionalised elderly 15-50%
100% in long term in dwelling catheters
Pathogens is I of UTIs, what is the most common route?
The ascending route
How does the ascending route occur
Intestinal flora comes though GI tract and migrates across the skin to the urethra
Some strains are uropathogenic (can live in urine)
What can cause uropathogenic strains more likely to cause trouble/ appear
Diarrhoea
Oestrogen deficiency
Spermicides (increase numbers and adherence)
Urodynamics (flow and structure anatomy)
Bacteria with motile flagellate and adherence, allows them to ascent
How are these bacteria able to move? And bind
Motile flagella
Called type 1 fimbriae
.bind to mannose-containing epithelial receptors: uroplakin 1 and 2
.tamm horsfall protein which is shed in the urine to fools the e.coli to bind on to that instead and so flushed out
.IgA produced to binds to e.coli to prevent it binding
Also have p fimbriae to bind
What is P fimbriae
Produced by the bacteria which bing to Gal-Gal, on urethral epithelial cells
What other components does urobacteria like?
Urea as food
Acidic environment
What is the inflammatory response to a UTI
PMNs
Cytokines
Humoral Immune system
And the most common pathogens for UTI
Escherichia coli
Staphylococcus saprophyticus (sexually active young women)
Proteus (swarms) Pseudomonas Klebsiella Enterobacter Enterococcus Staphylococcus aureus
What is the antibiotic route of UTI called?
Haematogenous route
List symptoms to lower UTI
Cystitis Dysuria Frequency Urgency Suprapubic pain/tenderness Can have haematuria or fever Cloudy, smelly urine
Lost symptoms of pyelonephritis (upper UTI of the kidneys I)
Lion pain and tenderness (where kidneys are)
Fever
Sometimes nausea and vomiting
With/without lower tract symptoms
List the presentations in children and older adults
Children - failure to thrive due to recurrent infections
Older adults - can just be confusion and ‘off legs’
Urinalysis
What happens if you find nitrite
Leucocyte esterase
Nitrite- don’t make it ourselves, formed by bacteria apart from enterococci
Others Blood Bilirubin Ascorbic acid Nitrofurantoin
False negatives if there’s blood, lots of bilirubin, on antibiotics
Urine microscopy to confirm diagnosis
Pyuria - >100 leukocytes/ml
Culture >105 organisms /ml
List the management for asymptomatic UTI
Repeat urine culture and watch for development of symptoms
Expect if pregnant, means that they have an increased likelihood of earlier delivery. You would treat.
Or ureter transplant people
List the management for symptomatic
Empirical treatment or treat after urinalysis
May need imaging
List non-specific therapy for UTI
Fluid rehydration
Urinary pH- low pH is antibacterial
Analgesia- not recommended for treatment but may help symptom
List the useful agents for UTI (good at getting in Urine)
Nitrofurantoin
Picmecillinam
Fosfomycin
Oral cephalosporins
Co-amoxiclav
IV tazocin
What is the length of treatment for cystitis and pyelonephritis
Cystitis- 3 days
Pyelonephritis 10-14 days, not all treatments get in the kidney
What is the definitions for UTIs in
Cure
Persistence
Relapse
Reinfection.
Cure - negative culture 1-2 weeks after treatment
Persistence - bacteruria 48 hours after treatment
Relapse - within 1-2 weeks with the same organisms
Reinfection - different bug whilst on treatment or after finishing
Name the key syndromes of STIs
Genital ulcer
Genital discharge
Other lesions
Describe feature of herpes simplex 2 everything u know
Painful ulcers with local lymphadenopathy
Recurrent
Confirm diagnosis with PCR
Treat with aciclovir
May need long term suppression
May shed virus without ulcers
Describe Primary chancre Latency Secondary syphilis Tertiary syphilis
Primary chancre - painless, May heal spontaneously, local lymphadenopathy
Latency - still there
Secondary syphilis - many different presentations (macular, coppery rash, May involve palms and soles), core generalised lymphadenopathy, condylomata lata (moles). Can become latent
Tertiary syphilis- lots of presentations
How do we treat syphilis (early, no tertiary)
Benzathine pencilling G
Procaine penicillin
Doxycycline (if allergic)
How to treat tertiary syphilis
Including neurosyphilis and late latent syphilis
Benzathine penicillin or doxycycline
Monitor serological response
Reinfection possible
Tell me what you know about chancroid
Has ulcers similar to syphilis but the base is more necrotic with exudate (ooze)
Usually single lesions caused by gram-negative organism
Treat with azithromycin or ceftriaxone
Name two other ulcers not talked about in detail
Granuloma inguinale
Lymphogranuloma venereum
What should you do about urethritis/certvictis
Swan for gram stain, culture looking for diplococci- looking for gonorrhoea
Urinalysis and NAAT testing
Urethritis and cervicitis is often a co-infection, with what?
Neisseria gonorrhoea
Non-gonococcal
.chlamydia
.ureaplasma
.HSV
Other than discharge, what else can gonorrhoea cause?
And same for chlamydia
Conjunctivitis Septic arthritis Pharyngeal infection Peri-hepatitis Disseminated disease
Conjunctivitis for chlamydia
How to treat gonorrhoea
Ceftriaxone
And
Azithromycin
But have found extreme resistant gonorrhoea
New guidance
CRO and doxycycline
Say some things about genital warts - HPV
Diffuse range of size and shape
Usually asymptomatic
If very large and cauliflower like called- condylomata aluminata
Treatment is with scraping, cryotherapy, keratolytics, podophyllin, imiquimod
