Bacterial sexually transmitted & urinary tract infections Flashcards
What are the 2 types of UTIs?
Complicated
Uncomplicated
Describe uncomplicated UTI
Non-pregnant women
No known relevant anatomical/functional abnormalities in urinary tract
Acute, sporadic, recurrent cystitis (inflammation of the bladder)
Describe complicated UTI
Congenital abnormality - obstruction, neurological dysfunction
Acquired abnormality - obstruction, neurological dysfunction
Catheter if symptomatic
Young male patient - men do not get UTIs unless there is an underlying reason
Pregnancy
Repeated upper urinary tract infection
Recurrent infections may be common
Why is the incidence of UTIs higher in females?
Shorter urethra so bacteria can ascend through the ureters faster
What is the source of organisms causing UTIs?
Bacterial flora of the large bowel
Uropathogenic properties
What is vesico-ureteric reflux?
Abnormal flow of urine back up the ureters to the kidneys
Can lead to upper urinary tract infection (pyelonephritis)
What is pyelopnephritis?
Bacterial infection causing inflammation of kidneys
Occurs as consequence of ascending UTI which spreads from bladder to kidneys
What is the main cause of complicated and uncomplicated UTIs?
UPEC (uropathogenic Escherichia coli)
What is asymptomatic bacteriuria?
Presence of bacteria in a urine sample of an individual that shows no signs or symptoms of a UTI
Why is asymptomatic bacteriuria important?
Rarely causes serious problems unless there is presence of urinary reflux or stasis, in which case cystitis or pyelonephritis may develop
What are risk factors of getting asymptomatic bacteriuria?
Female sex
Sexual activity
Diabetes particularly women
Age
Institutionalisation
Presence of catheter
Describe urethral syndrome
UTI symptoms but no evidence of infection
Occurs in women ages 30-50
Unknown cause of infection with unusual organisms
Variety of non-antibiotic treatments
What is cystitis?
Superficial inflammation of urethra and bladder
More frequent in women
What can cystitis lead to?
Upper tract infection
What are symptoms of cystitis?
Frequency
Dysuria - pain when passing urine
Haematuria - blood in urine
Urgency
Suprapubic discomfort
Polyuria
What is pyelonephritis?
Upper UTI
Direct invasion of renal tissue
What are signs and symptoms of pyelonephritis?
Back pain
Fever
Rigors
Renal angle tenderness
May have cystitis
May develop bloodstream infection/sepsis
What can develop from bacteraemia?
Renal abscess - blood borne spread e.g Staphylococcus aureus
How are UTIs diagnosed?
Urinary dipsticks
What do urinary dipsticks look for?
Nitrite detection - bacteria convert nitrate to nitrite
RBCs
WBCs
Protein
What is another quick test that can be done to check for a UTI?
Check if urine is turbid (cloudy) - indicates discharge of blood/pus due to UTI OR increased WBCs in urine due to UTI
How is microscopy used to look for UTIs?
Presence of WBCs, RBCs, bacteria, casts
How are cultures used to look for UTIs?
Quantification of bacteria on selective/differential media
Can see lower counts in early stages of UTI
How is sensitivity used for UTI testing?
Check what antibiotics the organisms are sensitive/susceptible to
What factors determine management of UTIs?
Age
Sex
Pregnancy
Catheter
Or any other complications
What are symptomatic treatments of UTIs?
Hydration
Analgesia
Alkalisation of urine - potassium citrate; relieves symptoms
Can be combined with antibiotics unless mild infection in adult female where antibiotics may be delayed
What is antibiotic-prophylaxis?
Antibiotics given to prevent infection
Recommended in children with recurrent infection
Used in some adults with recurrent infection
No help in preventing catheter related infections
Use if instrumentation of infected urine to prevent bacteraemia
What are non-antibiotic treatments for UTIs?
Oestrogen suppositories for post-menopausal women
L-Mannose
Cranberry juice/capsules - polyphenols/proanthocyanidins inhibit adhesion of type-1 pili & reduce inflammation
What types of STIs are there?
Bacterial
Viral
Parasitic
Infestations
What are STI syndromes?
Genital discharge
Genital ulcer disease
Genital and pelvic pain
Dermatoses
What increases the risk of HIV?
Herpes
Syphilis
What are long-term consequences of STIs?
Infertility
Ectopic pregnancy
Mother to child (MTC) transmission
Describe AMR gonorrhoea
High fluoroquinolone resistance
Increasing azithromycin resistance
Emerging resistance of extended-spectrum cephalosporins
What are the 4 curable STIs?
Chlamydia
Gonorrhoea
Trichomoniasis
Syphilis
What causes genital ulcer disease?
Syphilis
Herpes
Chancroid
Lymphogranuloma venereum (LGV)
Granuloma inguinale (Donovanosis)
Bacterial infection e.g Staphylococcus infection
What is the bacterium causing syphilis?
Treponema pallidum
What is early syphilis?
First 2 years of infection
High replication rate of T.pallidum
Relapsing early disease and infectious
What is late syphilis?
After 2 years of infection
Low replication rate of T.pallidum
Late disease over decade
Non-infectious
Remains in the body and can reactivate over decades and cause various diseases
What is the timeline of syphilis infection including symptoms?
Primary syphilis - incubation 9-90 days, chancres
Secondary syphilis - up to 2 years, skin and systemic features
Tertiary syphilis - over 10 years later, neuro, cardiac and skin
What are condylomata lata?
One of the cutaneous signs of secondary syphilis
Wart-like lesions on genitals
Most infectious skin lesions in syphilis
How is syphilis diagnosed?
Dark ground microscopy from early lesions
- scrub lesion with n.saline, scrape tissue fluid from ulcer base, with cover slip
- under microscope look for corkscrew motility, slinky motility, bendy motility
Alternative = PCR based tests
What is another way of diagnosing syphilis?
Serological tests on blood
Describe gonorrhoea
Gram negative intracellular diplocccus
Genital discharge syndrome
50% of men are asymptomatic
Less than 5% of females are asymptomatic
50% have concurrent other STIs e.g. Chlamydia
What can gonorrhoea cause?
Ophthalmia neonatorum
Keratitis and rapid corneal scarring
Pelvic inflammatory disease
Ectopic pregnancy
Infertility
Congenital disease
Adult gonococcal conjunctivits
Disseminated gonococcal infection
What increases with gonorrhoea infection?
Risks of HIV transmission
Antimicrobial resistance
What are mechanisms of Neisseria gonorrhoeae resistance to antimicrobials?
Chromosomal mediated
Plasmid mediated
Host/microbiome related Rx failure
What is the chromosomal mediated mechanism?
Resistance genes easily transferred between strains through highly competent DNA transformation - pil-IV ComP receptor for DNA uptake sequences
Mosaics common
Mutation and clonal expansion
Mutation and internal recombination
Where is M.genitalium detected?
Upper GI tract in women with pelvic inflammatory disease
What can M.genitalium cause?
Cervicitis
Pelvic inflammatory disease
Preterm birth
Spontaneous abortion
Infertlity
Describe antibiotic resistance to macrolides
Mutations at A2058, A2059, A2062 in 23S rRNA
Describe antibiotic resistance to quinolones
Mutations at M95 and D99 in gyrA
Mutations at S83 and D87 in parC within QRDR
Where do macrolides act?
Bind to 50S subunit targeting 23S rRNA
Where do quinolones act?
Bind to DNA gyrase and topoisomerase IV
Where do tetracyclines act?
Bind to 30S ribosomal subunit in mRNA complex
What is used to treat Chlamydia trachomatis?
Doxycycline
What is used to treate Neisseria gonorrhoea?
Ceftriaxone
Azithromycin
What is used to treat Trichomonas vaginalis?
Metronidazole
What is used to treat Mycoplamsa genitalium?
Doxycyline + Azithromycin OR
Moxifloxacin or Pristinamycin
Describe antibiotic resistance of Neisseria gonorrhoeae
In UK 50% not resistant to ciproflaxacin /penicillin
Describe antibiotic resistance of Mycoplasma genitalium
40-50% not resistant to azithromycin
50-80% not resistant to moxifloxacin
What is the classification of chlamydia?
Intracellular bacterium serovars D-K of C. trachomatis
What are clinical features of chlamydia in males?
50% asymptomatic
Urethral discharge
Dysuria
Epididymo-orchitis
What are clinical features of chlamydia in females?
80% asymptomatic
Post-coital bleeding
Deep pain with sex
Pelvic pain, cervicitis
Vaginal discharge (rare)
Tubal-factor infertility
What are some complications of chlamydia?
Reactive arthritis
Reiters syndrome
Conjunctivitis
Neonatal infection
How is chlamydia diagnosed?
Nucleic acid amplification test (NAAT) - urethra cervix, vulvo-vagina, rectal, urine
How is chlamydia managed?
Doxycycline 1 week
Abstinence for 1 week
Contact tracing
How is gonorrhoea classified?
Intracellular bacterium Neisseria gonorrhoeae
What are clinical features of gonorrhoea in males?
Asymptomatic
Urethral discharge
Dysuria
Epididymo-orchitis
What are clinical features of gonorrhoea in females?
Asymtomatic
Deep pain with sex
Pelvic pain
Bartholins abscess
What are some complications of gonorrhoea?
Disseminated infection
Arthritis
Conjunctivitis
Neonatal infection
How is gonorrhoea diagnosed?
Gram stained smear and culture
NAAT
How is gonorrhoea managed?
3rd gen cephalosporin or if sensitivity is known then ciproflaxin/amoxicillin with probenecid
PLUS empirical treatment for chlamydia (doxycyline for 1 week)
Abstinence for 1 week
Contact tracing
How is trichimonas vaginalis classified?
Flagellate protozoan trichomonas vaginalis
What are clinical features of TV in males?
Mostly asymptomatic
Urethral discharge
Dysuria
What are clinical features of TV in females?
10-50% asymptomatic
Vaginal discharge
Vulval irritation
How is TV diagnosed?
Microscopy of vaginal discharge in saline on a glass slide demonstrating motile protozoa
Culture on Feinberg Whittington medium
PCR
What are complication of TV?
Preterm delivery - low birth weight
Pelvic inflammatory disease
May facilitate HIV acquisition
How is TV managed?
Metronidazole 400mg BD 5 days
Abstinence for 1 week
Contact tracing (current partners)
