Infections
Anne Lee, Sally Inch, David Finnigan in Therapeutics in Pregnancy and Lactation, 2019
Asymptomatic bacteriuria is defined as urinary tract infection in the absence of any symptoms, with greater than 100 000 bacteria/mL in a midstream urine sample.48 It occurs in 5–10% of pregnancies, with similar prevalence in nonpregnant women.48Escherichia coli is the most common pathogen; other organisms include Klebsiella species, Proteus species, enterococci, staphylococci and group B streptococcus.49,50 In non-pregnancy, asymptomatic bacteriuria is harmless and does not require treatment. In pregnancy, however, 20–30% of women will develop acute pyelonephritis unless treated.48 Asymptomatic bacteriuria is also associated with an increased risk of premature birth.2,48
The urinary tract and male reproductive system
C. Simon Herrington in Muir's Textbook of Pathology, 2020
Urinary tract infection may involve either the bladder or the kidneys and renal pelvis, or both. The single most important criterion for the diagnosis of urinary tract infection is the presence of bacteria in the urine, called bacteriuria. In urine obtained through a bladder catheter the presence of an organism is significant whereas in the commonly used midstream sample there may be some contamination by urethral or perineal organisms. In these latter samples a bacterial count of ≥105/mL is accepted as definitive of infection. Bacteriuria in the absence of symptoms is termed ‘asymptomatic bacteriuria’ and is of importance under two circumstances: In infancy, where, in the presence of ureteric reflux, it can lead to ascent of infection to the kidney.In pregnancy, where it may be followed by symptomatic infection predisposing to hypertension, pre-eclampsia, and prematurity.
Urinary tract infections in pregnancy
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
For asymptomatic women, bacteriuria is diagnosed by quantitative urine culture: two consecutive voided specimens with isolation of the same bacterial strain in quantitative counts ‡105 bacteria/mL or a single catheterized urine specimen containing ‡102 bacteria/mL (36). Although only approximately 80% of women with a positive initial screening culture would have that confirmed on subsequent sampling, the detection of ‡105 bacteria/mL in a single voided midstream urine is generally accepted as an adequate and more practical alternative to the requirement for serial positive samples (37). The bacteria identified in ASB are generally similar to those of other UTIs, except that group B streptococcus is more common in this UTI, present in approximately one-quarter of positive screening cultures (8,38).
Urinary tract infection during pregnancy: current concepts on a common multifaceted problem
Published in Journal of Obstetrics and Gynaecology, 2018
Kallirhoe Kalinderi, Dimitrios Delkos, Michail Kalinderis, Apostolos Athanasiadis, Ioannis Kalogiannidis
Urinary tract infections in pregnancy are classified as either asymptomatic or symptomatic. Asymptomatic bacteriuria is defined as the isolation of bacteria in at least 1 × 105 colony-forming units per mL of cultured urine, in the absence of signs or symptoms of a UTI. Symptomatic UTIs are divided into lower tract (acute cystitis) or upper tract (acute pyelonephritis) infections (Bahadi et al. 2010). Asymptomatic bacteriuria occurs in 2–15% of pregnant women and is a major risk factor for developing symptomatic UTIs during pregnancy (Ipe et al. 2013). The prevalence of symptomatic urine infection during pregnancy is less common, complicating about 1–2% of all pregnancies (Schnarr and Smaill 2008). Among symptomatic UTI, cystitis is defined as significant bacteriuria with associated bladder mucosal invasion, whereas pyelonephritis is defined as significant bacteriuria with associated inflammation of the renal parenchyma, calices and pelvis. The major symptoms of cystitis are dysuria, urgency and frequent urination and the affected patient may present with suprapubic tenderness. Pyelonephritis is usually accompanied by fever, lumbar pain, nausea and vomiting. If asymptomatic bacteriuria is untreated, 20–40% of cases progress to acute UTI, such as pyelonephritis and can likely cause multiple pregnancy complications, including premature delivery in 20–50% of cases (Whalley 1967; Patterson and Andriole 1997; MacLean 2001).
The uncertainties of the diagnosis and treatment of a suspected urinary tract infection in elderly hospitalized patients
Published in Expert Review of Anti-infective Therapy, 2018
Paul Froom, Zvi Shimoni
The prevalence of asymptomatic bacteriuria is also dependent on the definition of bacteriuria. A common definition of bacteriuria is ≥ 105 CFU/mL [1,3–5], but others have used lower cutoffs such as ≥ 104 and even ≥ 102 under certain circumstances. In 2012, the Society for Healthcare Epidemiology of America (SHEA) updated the surveillance definitions of infections in long-term care facilities and defined bacteriuria in cultures with only ≥ 102 CFU/mL [10] in a sample obtained by a urinary catheterization procedure. Recently, the Centers for Disease Control and Prevention however, revised the definition of a catheter associated urinary tract infection [41], increasing the minimum bacterial colony count from ≥ 104 to ≥ 105 CFU/mL. These are consensus decisions that are not evidence based because the proper cutoff for diagnosing significant bacteriuria that will best aid in the diagnosis and treatment of the elderly is uncertain.
Sepsis in urology – where are we now? And where are we going?
Published in Scandinavian Journal of Urology, 2020
William Duggan, Diarmaid Moran, Ben Challacombe
Endogenous risk factors, are a consequence of co-morbidity, organic dysfunction or anatomical abnormality. Age and immunodeficiency are well established risk factors for the development of infection. Diabetes mellitus is of particular importance when we consider urological patients, as diabetics are more likely to have asymptomatic bacteriuria and urinary tract infection [8]. Bacterial colonisation and the factors that affect the location and spectrum of organism are also critically important. Recent hospitalisation, antibiotic use, prolonged catheterisation and the presence of urinary tract calculi have all been associated with increased rates of HAUTI [9]. Similarly the presence of anatomical abnormalities lending to altered microbial flora or urinary stasis can increase prevailing level of risk.