|Multiple rod-shaped bacteria shown between the larger white blood cells at urinary microscopy from a person with urinary tract infection.|
|Specialty||Emergency medicine, Infectious disease|
|Diagnostic method||Urinalysis, urine culture|
|Treatment||Based on symptoms or risk factors|
|Frequency||Asymptomatic: 3% (middle aged women), up to 50% (women in nursing homes)|
Symptomatic: up to 10% of women a year
Bacteriuria is the presence of bacteria in urine. It is divided into two main types, those with symptoms (urinary tract infection) and those without (asymptomatic bacteriuria). Diagnosis is by urinalysis or urine culture. Escherichia coli is the most common bacterium found. Most people without symptoms should not be tested for the condition. Differential diagnosis include contamination. Using special techniques certain non-disease causing bacteria have also been found in the urine of healthy people. These are part of the resident microbiota.
If symptoms are present treatment is generally with antibiotics. Bacteriuria without symptoms generally does not require treatment. Exceptions include during pregnancy, those who have had a recent kidney transplant, young children with significant vesicoureteral reflux, and in those undergoing surgery of the urinary tract.
Bacteriuria without symptoms is present in about 3% of otherwise healthy middle aged women. Among those in nursing homes rates are as high as 50% among women and 40% in men. In those with a long term indwelling urinary catheter rates are 100%. Up to 10% of women have a urinary tract infection in a given year and half of women having at least one infection at some point in their lives.
Signs and symptoms
Asymptomatic bacteriuria is bacteriuria without accompanying symptoms of a urinary tract infection. It is more common in women, in the elderly, in residents of long-term care facilities, and in people with diabetes, bladder catheters and spinal cord injuries. People with a long-term Foley catheter uniformly show bacteriuria. Chronic asymptomatic bacteriuria without urinary tract infection symptoms occurs in as many as 50% of the population in long-term care.
Symptomatic bacteriuria is bacteriuria with the accompanying symptoms of a urinary tract infection (such as frequent urination, painful urination, fever, back pain). Symptomatic bacteriuria can be indicative of a urinary tract infection like pyelonephritis or cystitis. The most common type of bacteriuria associated with urinary tract infections is Escherichia coli which is a gram-negative rod-shaped bacteria.
Testing for bacteriuria is often performed in those with symptoms of a urinary tract infection. Testing is often done in other scenarios as in failure to thrive of a newborn or confusion in the elderly. Screening for bacteriuria is recommended in pregnancy as there is evidence that asymptomatic bacteriuria can lead to low birth weight and preterm delivery.
- Bacteriuria can be detected by urine dipstick test. The urinary nitrite test will be able to detect any nitrate-reducing bacteria in the urine. The leukocyte esterase test detects the presence of leukocytes (white blood cells) in the urine which can be associated with a urinary tract infection.The urine dipstick test is readily available and provides fast results.
- Microscopy can also be used to detect bacteriuria. It is more specific, especially when used with gram staining, but requires more time and equipment.
- The gold standard for detecting bacteriuria is a bacterial culture which identifies the actual organism. This test is more specific but can take several days to obtain a result. As a result, clinicians will often treat a bacteriuria based on the results of the urine dipstick test while waiting for the culture results. The culture will often provide antibiotic sensitivity.
Bacteriuria can be confirmed if a single bacterial species is isolated in a concentration greater than 100,000 colony forming units per millilitre of urine in clean-catch midstream urine specimens (one for men, two consecutive specimens with the same bacterium for women). For urine collected via bladder catheterization in men and women, a single urine specimen with greater than 100,000 colony forming units of a single species per millilitre is considered diagnostic. The threshold is also 100 colony forming units of a single species per millilitre for women displaying UTI symptoms.
One time screening for bacteriuria is tentatively recommended during early pregnancy.
The decision to treat bacteriuria depends on the presence of accompany symptoms and comorbidities.
Asymptomatic bacteriuria generally does not require treatment. Exceptions include during pregnancy and in those undergoing surgery of the urinary tract. Children with vesicoureteral reflux or others with structural abnormalities of the urinary tract.[unreliable medical source?]
There is no indication to treat asymptomatic bacteriuria in diabetics, renal transplant recipients, and in those with spinal cord injuries.
The overuse of antibiotic therapy to treat asymptomatic bacteriuria has many adverse effect as it increases the risk of diarrhea, antimicrobial resistance, and infection due to Clostridium difficile. Other effects include increased financial burdens and overreporting of mandated catheter-associated urinary tract infection.
|Group||Prevalence (in %)|
|Healthy premenopausal women||1.0 to 5.0|
|Pregnant women||1.9 to 9.5|
|Postmenopausal women (50 to 70 years of age)||2.8 to 8.6|
|People with diabetes mellitus||Women||9.0 to 27.0|
|Men||0.7 to 1.0|
|Older community-dwelling people||Women (older than
|Men||3.6 to 19.0|
|Older long-term care residents||Women||25.0 to 50.0|
|Men||15.0 to 40.0|
|People with spinal cord injury||Intermittent catheter||23.0 to 89.0|
|People undergoing hemodialysis||28.0|
|People with an indwelling
|Short-term||9.0 to 23.0|
- Das, K. V. Krishna; Das, KV Krishna (2017). Textbook of Medicine: Two Volume Set. JP Medical Ltd. p. 1250. ISBN 9789386056108.
- Sendi, P; Borens, O; Wahl, P; Clauss, M; Uçkay, I (2017). "Management of Asymptomatic Bacteriuria, Urinary Catheters and Symptomatic Urinary Tract Infections in Patients Undergoing Surgery for Joint Replacement: A Position Paper of the Expert Group". Journal of bone and joint infection. 2 (3): 154–159. doi:10.7150/jbji.20425. PMC 5592375. PMID 28894690.
- "Bacterial Urinary Tract Infections (UTIs)". Merck Manuals Professional Edition. May 2016. Retrieved 12 December 2017.
- Köves, B; Cai, T; Veeratterapillay, R; Pickard, R; Seisen, T; Lam, TB; Yuan, CY; Bruyere, F; Wagenlehner, F; Bartoletti, R; Geerlings, SE; Pilatz, A; Pradere, B; Hofmann, F; Bonkat, G; Wullt, B (25 July 2017). "Benefits and Harms of Treatment of Asymptomatic Bacteriuria: A Systematic Review and Meta-analysis by the European Association of Urology Urological Infection Guidelines Panel". European Urology. 72 (6): 865–868. doi:10.1016/j.eururo.2017.07.014. PMID 28754533.
- Colgan, R; Nicolle, LE; McGlone, A; Hooton, TM (15 September 2006). "Asymptomatic bacteriuria in adults". American Family Physician. 74 (6): 985–90. PMID 17002033.
- Salvatore S, Salvatore S, Cattoni E, Siesto G, Serati M, Sorice P, Torella M (June 2011). "Urinary tract infections in women". European journal of obstetrics, gynecology, and reproductive biology. 156 (2): 131–6. doi:10.1016/j.ejogrb.2011.01.028. PMID 21349630.
- Nicolle LE (2008). "Uncomplicated urinary tract infection in adults including uncomplicated pyelonephritis". Urol Clin North Am. 35 (1): 1–12, v. doi:10.1016/j.ucl.2007.09.004. PMID 18061019.
- Schneeweiss J., Koch M., Umek W. (2016). "The human urinary microbiome and how it relates to urogynecology". Int Urogynecol J. 27 (9): 1307–12. doi:10.1007/s00192-016-2944-5. PMID 26811114.
- AMDA – The Society for Post-Acute and Long-Term Care Medicine (February 2014), "Ten Things Physicians and Patients Should Question", Choosing Wisely: an initiative of the ABIM Foundation, AMDA – The Society for Post-Acute and Long-Term Care Medicine, retrieved 20 April 2015
- Smaill, Fiona M.; Vazquez, Juan C. (2015-08-07). "Antibiotics for asymptomatic bacteriuria in pregnancy". The Cochrane Database of Systematic Reviews (8): CD000490. doi:10.1002/14651858.CD000490.pub3. ISSN 1469-493X. PMID 26252501.
- Szweda, Hanna; Jóźwik, Marcin (2016). "Urinary tract infections during pregnancy - an updated overview". Developmental Period Medicine. 20 (4): 263–272. ISSN 1428-345X. PMID 28216479.
- Detweiler K, Mayers D, Fletcher SG (November 2015). "Bacteruria and Urinary Tract Infections in the Elderly". The Urologic Clinics of North America (Review). 42 (4): 561–8. doi:10.1016/j.ucl.2015.07.002. PMID 26475952.
- Sam, Amir H.; James T.H. Teo (2010). Rapid Medicine. Wiley-Blackwell. ISBN 978-1-4051-8323-9.
- Moore, Ainsley; Doull, Marion; Grad, Roland; Groulx, Stéphane; Pottie, Kevin; Tonelli, Marcello; Courage, Susan; Garcia, Alejandra Jaramillo; Thombs, Brett D. (8 July 2018). "Recommendations on screening for asymptomatic bacteriuria in pregnancy". Canadian Medical Association Journal. 190 (27): E823–E830. doi:10.1503/cmaj.171325. PMID 29986858.
- Ramos, Jorge A.; Salinas, Diego F.; Osorio, Johanna; Ruano-Ravina, Alberto (September 2016). "Antibiotic prophylaxis and its appropriate timing for urological surgical procedures in patients with asymptomatic bacteriuria: A systematic review". Arab Journal of Urology. 14 (3): 234–239. doi:10.1016/j.aju.2016.05.002. ISSN 2090-598X. PMC 4983160. PMID 27547467.
- Asymptomatic bacteriuria from Medline Plus. Updated May 26, 2006, retrieved January 28, 2008.
- Nicolle, Lindsay E. (2014). "Urinary Tract Infections in Special Populations". Infectious Disease Clinics of North America. 28 (1): 91–104. doi:10.1016/j.idc.2013.09.006. PMID 24484577.
- Zalmanovici Trestioreanu, A; Lador, A; Sauerbrun-Cutler, MT; Leibovici, L (8 April 2015). "Antibiotics for asymptomatic bacteriuria". The Cochrane Database of Systematic Reviews. 4: CD009534. doi:10.1002/14651858.CD009534.pub2. PMID 25851268.