A urinary tract infection (UTI) is an inflammatory response of the urothelium to bacterial invasion that is usually associated with bacteriuria and pyuria.
UTIs can happen anywhere in the urinary system, which include :
UTIs are most common in the bladder. A UTI in the bladder is called cystitis, infections in the bladder can spread to the upper part of the urinary tract or the kidneys. This UTI in the kidneys is called pyelonephritis.
Furthermore, UTIs are considered to be the most common bacterial infection and most bacteria enter the urinary tract from the bowel reservoir via ascent through the urethra into the bladder.
The majority of UTIs are caused by a single bacterial species.
At least 80% of UTIs are due to Escherichia coli. Other, less common in uropathogens, include Klebsiella, Proteus, and Enterobacter spp. and enterococci.
Group B beta-hemolytic streptococci can cause UTIs in pregnant women and Staphylococcus saprophyticus can cause UTIs in young women.
The prevalence of bacteriuria in young women is 30 times more than in men. Survey data suggest that approximately;
60% of women will experience symptomatic acute bacterial cystitis in their lifetime and when the first infection is caused by Escherichia coli, an estimated 20-40% of these women develop a second cystitis episode within six months.
Due to the women anatomy, women are more likely to develop UTIs, because the urethras are shorter and closer to the rectum. This makes it easier for bacteria to enter the urinary tract.
Other factors that can increase the risk of UTIs: I’m women include:
Sexual intercourse & lack of post coital voiding
A new sexual partner
The use of Diaphragms, spermicide
Atrophic vaginitis due Estrogen deficiency
In addition, UTIs are also frequently encountered in pregnant and post menopausal women. UTIs the most common bacterial infections during pregnancy. The changes of the urinary tract and immunologic changes of pregnancy predispose women to urinary tract infection. Physiologic changes of the urinary tract include dilation of the ureter and renal calyces; Decreased bladder capacity and vesicoureteral reflux may be seen.
On the other hand, postmenopausal women have frequent reinfections. These infections are sometimes attributable to residual urine after voiding, which is often associated with bladder or uterine prolapse. In addition, the lack of estrogen causes marked changes in the vaginal microflora, including a loss of lactobacilli and increased colonization by E. coli
The most common symptoms are:
Increased urinary urgency and frequency
Acute-onset dysuria is a highly specific symptom, with more than 90% accuracy for UTI in young women, however in elderly women genitourinary symptoms are not necessarily related to cystitis.
The diagnosis of UTIs can be made based on a focused history of LUTS (dysuria, frequency and urgency) and the absence of vaginal discharge. These symptoms should occur in conjunction with a urinalysis and confirmed by detection of a uropathogen from the urine cultures.
The antibiotic treatment for UTIs is individual based on the URO pathogen identified in the urine cultureX. However, there are behavioral modifications, which might reduce the risk of recurrent UTIs.
These modifications include:
Increase fluid intake.
Habitual and post-coital delayed urination.
Prophylaxis with cranberry.
Cranberry juice contains proanthocyanidins that block adherence of pathogens to uroepithelial cells. Studies show that un in low-risk patients 200 to 750 mL daily of cranberry juice or cranberry-concentrate tablets reduce the risk of symptomatic, recurrent infections by 12% to 20%.
Use of Probiotics.
Intermittent and chronic antibiotic usage damages the intestinal flora. Probiotics such as lactic acid bacteria can restore normal intestinal flora and promote good host defense.
Intravaginal administration of estriol in post-menopausal.
Estrogen replacement restores atrophic mucosa, lowers vaginal pH, and may prevent urinary tract infections.
A Controlled Trial of Intravaginal Estriol in Postmenopausal Women with Recurrent Urinary Tract Infections.Raul Raz, and Walter E. Stamm. DOI: 10.1056/NEJM199309093291102
EAU Guidelines on Urological Infections (2021)
AUA. Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline (2019)
Campbell-Walsh Urology. Eleventh Edition. Chapter 12 Infections of the Urinary Tract.
Naber KG, Bonkat G, Wagenlehner FME. The EAU and AUA/CUA/SUFU Guidelines on Recurrent Urinary Tract Infections: What is the Difference? Eur Urol. 2020 Nov;78(5):645-646. doi: 10.1016/j.eururo.2020.06.032. Epub 2020 Jun 29. PMID: 32616407.
Urinary Tract Infection In Pregnancy. Patricia J. Habak; Robert P. Griggs, Jr.
Valiquette L. Urinary tract infections in women. Can J Urol. 2001 Jun;8 Suppl 1:6-12. PMID: 11442991.