9 Sexually transmitted + urinary infections Flashcards
prevalence of symptomatic UTIs in men and young non-pregnant women
<0.1%, 1-3%
incidence of symptomatic UTIs in women increase with..
age and if they’re sexually active
what is asymptomatic bacteriuria
when there is bacteria in the urine but is causing no symptoms or problems, no adverse outcomes on follow up
100% of long term indwelling catheters
what is the main route of getting a UTI and what other is rare
the ascending route= main
haematogenous route= through blood, rare
describe the ascending route
intestinal flora comes down lower GI tract and lives on surface of skin
migrates towards gynae and urethra
get vaginal and urethral colonisation of uropathogenic strains of bacteria
gradually bacteria climb up urethra
what increases the chance of vaginal and peri-urethral colonisation (4)
diarrhoea
oestrogen deficiency- change in bacterial flora
spermicides- increase bacterial numbers and adherence
antibiotics
urodynamics preventing UTIs
urine flushes out bacteria in urethra, problem with structure can cause difficulties
what makes bacteria good at climbing up urethra
motile flagellae
adherence
describe how bacteria climbs up urethra through 2 mechanisms of motile flagellae
type 1 fimbriae of bacteria bind to mannose-containing epithelial receptors Uroplakin 1 and 2 of urethra (spiderman)
we produce Tamm Horsfall Protein to fool E.coli/bacteria to bind to it instead, and remove in urine
IgA also binds
ALSO
produces P fimbriae which binds to Gal-Gal which are present on surface of urethral epithelial cells (and red blood cells)
name 2 motile flagellae bacteria has
type 1 and P
what is a convene
like a condom with a tube at the end, urine goes through into a bag, instead of a urinary catheter
risk of UTI
pathogens in UTIs
main= E. Coli Staphylococcus saprophyticus= 5-15% of sexually active young women proteus pseudomonas klebsiella enterobacter enterococcus staphylococcus aureus- doesn't typically ascend, haematogenous, take another sample and also take blood culture
what’s cystitis
pain on passing urine
symptoms of a lower UTI
cystitis dysuria frequency urgency suprapubic pain sometimes haematuria (blood in urine) and fever cloudy smelly urine
what is pyelonephritis
upper UTI infection, infection in kidneys
symptoms of pyelonephritis
loin pain and tenderness
fever
sometimes nausea and vomiting
+/- lower UTI symptoms
other presentations of UTIs
children under 2, failure to thrive
older adults, increased confusion
how to diagnose a UTI
sometimes based on history and examination alone
urinalysis
mid stream urine, start to wee, stop, start and take sample to avoid getting bacteria
what to look for in urinalysis for UTI
nitrite- formed by the action of bacterial nitrate reductase (NR) in enterobacteriacae
if no bacteria around, this shouldn’t happen, not always positive if bacteria is there since some don’t have NR
leucocyte esterase- chemical conversion of an ester
false negatives- in presence of blood, on antibiotics (nitrofurantoin, rifampicin)
false positives- co-amoxiclav
urine microscopy and culture
pyuria= white cells in urine
>100 leukocytes/ml is significant
culture if significant
>10^5 organisms/ml= diagnose
management of UTI
asymptomatic
- culture positive
- repeat urine culture
- always treat in pregnant women, because increased likelihood of early delivery
symptomatic
- be cautious in renally impaired
- empirial treatment or
- treat after urinalysis and send mid stream urine or
- treat after mid stream urine result is available
may need imaging
non-specific therapy for UTI
fluid re-hydration
urinary pH- low is antibacterial, difficult to keep low
analgesia not recommended but can be helpful for symptoms alleviation
antimicrobial chemotherapy- antibiotics for UTI
need ability to reach good concentration in urine, more important than in blood
dose modification in renal failure
nitrofurantoin- don’t use for anything else
pivmecillinam- penicillin but can still have if allergic
fosfomycin- one off dissoluble in water then 3 days later
oral cephalosporins- not always brilliant;y absorbed
co-amoxiclav- increasing resistance
(trimethoprim)- traditionally used but too high a resistance, use if sensitive but not empirically
(amoxicillin)- high resistance
if kidney infection
give IV because will be vomiting
tazocin
aminoglycosides (gentamicin)- monitor renal function
quinolones (ciprofloxacin)- oral so may not be helpful if vomiting
length of antibiotic treatment in UTIs
cystitis= 3 days, better than single dose and as good as 7 days
pyelonephritis= 10-14 days
be wary that some drugs might not get into kidney parenchyma
