Urinary Tract Infection

Written by

Tiny Health Team

Medically reviewed by

Nicole Calloway Rankins, MD, MPH

Scientifically reviewed by

Nicole Calloway Rankins, MD, MPH

Summary

One burning question: What is a urinary tract infection?

If you've had a urinary tract infection (UTI), you know the feeling. That urge to pee that suddenly arrives, the desperate run to the bathroom, to then pee just a couple of drops.

Ouch, it burns!

How do you get a UTI? A UTI occurs when unfriendly bacteria that usually live in the vagina or the gut make their way into the urethra and/or the bladder, grow, and cause inflammation [1].

80-90% of UTIs are caused by Escherichia coli. But other bacteria can also be involved:

Klebsiella pneumoniae
Staphylococcus saprophyticus
Enterococcus faecalis
Streptococcus agalactiae (Group B Strep)
Proteus mirabilis
Pseudomonas aeruginosa
Staphylococcus aureus [2]

Women are more likely than men to develop UTIs because their urethra is shorter. But there are also some things that may increase the risk of suffering these infections:

Having sex
Frequent pelvic exams
Using spermicides
Having a diaphragm
Pregnancy

Bacterial vaginosis [1], [3]–[5]

Consider yourself lucky if you've never had a UTI

UTI is one of the most common infections in women. About 50% of adult women will have at least one UTI in their life. And after the first episode, 27% will have a recurrent UTI within 6 months [6].

Pregnancy increases your risk of UTI due to hormonal and anatomical changes. About 2-15% pregnant women have asymptomatic presence of high numbers of bacteria in their urinary tract [7]. And about 1-2% develop an actual UTI [8].

Signs and symptoms of UTI

Unless you are one of those lucky women that have never experienced a UTI, you probably know the symptoms well:

Urge to pee
Difficulty starting urination
Pain or burning sensation when peeing
Peeing more often than normal
Lower abdomen discomfort, pelvic pressure
Blood in the urine

Other more severe symptoms may indicate the infection has reached the kidneys:

Fever
Chills
Nausea and vomiting
Back pain or pain in the flanks [1].

For some women, symptoms may start atypically and may be hard to relate these to a UTI. For example, you may have back pain for days without any other symptoms. If you suspect you may have a UTI or have had one in the past and you’re currently experiencing back or abdominal pain for several days, go see your provider. Taking your symptoms into account and performing a urine analysis will provide the correct diagnosis.

UTI-causing bacteria may originate from the vagina or the gut

Have you ever heard somebody say that urine is sterile? Well, turns out it’s not. Scientists have found that there is a microbiome in healthy urinary tracts. To no surprise, one of the most abundant bacteria in the urinary tract of healthy women are Lactobacillus species, the same that populate healthy vaginal microbiomes [9].

Scientists have identified various urotypes, that is, different types of urinary tract microbiomes. Some of the bacteria that can dominate these urotypes are Prevotella, Sneathia, Gardnerella, Atopobium, Lactobacillus, Shigella, Escherichia, Enterococcus, Streptococcus, and Citrobacter [10].

So then comes the obvious question, do bacteria in the urinary tract of women originate from the vagina? Scientists think the origin may be the vagina and/or the gut.

Let’s see first why some think UTI-causing bacteria come from the vagina:

One study found that the vaginal and bladder microbiome were very similar, but different from the gut microbiome [11].
Women with a history of recurrent or chronic UTI more commonly have E. coli in their vagina when compared to healthy women [12], [13]. Scientists think that this vaginal E. coli may contribute to recurrent UTI because in animal models with acute and chronic UTI, E. coli can invade and stay inside vaginal cells [14].
The vaginal microbiome of women with a history of UTI has low numbers of Lactobacillus [15]. And women with bacterial vaginosis are at increased risk of UTI [3]–[5].

But as we mentioned above, UTI-causing bacteria may also come from the gut:

One study found that 64% of bacterial species detected in the urine came from the gut, while only 32% came from the vagina [16].
Patients with UTI have high numbers of E. coli in their gut [17], [18].
High numbers of E. coli in the gut are associated with future development of UTI [19].

Besides, several beneficial gut bacteria have been found to be decreased in women with UTI, including Faecalibacterium, Akkermansia, Blautia, and Eubacterium hallii [20], [21].

Our Tiny Health gut test measures the levels of all these bacteria and tells you whether they are present below or above normal levels. Having low levels of protective bacteria and high levels of UTI-causing bacteria in your gut is one factor that may increase your risk of developing an UTI.

It’s also worth testing your vaginal microbiome to check for high levels of UTI-associated bacteria such as E. coli.

An untreated UTI can lead to complications

When treated promptly, UTI rarely leads to complications. Untreated UTIs, on the other hand, can lead to serious consequences, such as:

Recurrent or chronic UTI
Permanent kidney damage, if the infection reaches the kidneys
Blood infection

During pregnancy, having a UTI may also increase the risk of other complications for both mom and baby. But not all studies agree on this:

Preterm birth. Some studies found that having a UTI during pregnancy increases the risk of preterm birth [22], [23]. But other studies found just a slight increase in the risk, which wasn’t clinically relevant [24], [25]. Another study didn’t find any association between UTI and preterm birth [26].
Preeclampsia. Two studies found an association between UTI and preeclampsia [24], [25], while another one didn’t [22].
Endometritis or mastitis. One study found that UTI during pregnancy increases the risk of the mom of suffering endometriosis or mastitis during the postpartum period [22].

Due to all these possible complications, the U.S. Preventive Services Task Force recommends that all pregnant women are screened for the asymptomatic presence of bacteria in urine at 12-16 weeks gestation or at the first prenatal visit. This is because a low percentage of women with high numbers of bacteria in the urine will progress to kidney infection if not treated [27].

Treatments for UTI

Sometimes a UTI will resolve on its own after a few days. But if symptoms persist and become more severe, antibiotics may be needed.

But what is the best antibiotic for a UTI?

Usually, providers will choose an antibiotic based on the resistance rate in the area you live in and will consider previous treatments if you have experienced a UTI in the past.

However, it’s possible that UTI-causing bacteria are resistant to antibiotics [28].

Therefore, if antibiotics are needed, consider asking for an antibiotic susceptibility test. Knowing exactly which antibiotic is the right one for you will increase the chances of a successful treatment.

However, an antibiotic susceptibility test takes 1-2 days for the results to be ready. Going to your provider early on can give them enough time to do this. But if the infection is in an advanced state, it might be better to just start on antibiotics to prevent complications. The test can still be done after you begin the treatment, and if needed treatment can be changed based on the test results.

Another advantage of the test is having different antibiotic choices, which can help your provider choose one that has a lower impact on your microbiome. If using a narrow-spectrum antibiotic is possible, it will get rid of the UTI-causing bacteria while causing less damage to the good guys (unlike a broad spectrum antibiotic, which will kill much more bacteria).

Common antibiotics used to treat UTI are:

Amoxicillin
Ampicillin
Nitrofurantoin
Trimethoprim-sulfamethoxazole
Cefaclor
Cefalexin

Nitrofurantoin and trimethoprim-sulfamethoxazole are not recommended during the first trimester of pregnancy and near delivery if an alternative treatment is available [29]. These may be used anyways if you are allergic to other alternatives, because the benefits outweigh the risks.

Things you can do to prevent UTI or get rid of it faster

Want to stay away from UTIs? here are some things that may help you prevent them:

Pee after sex. This will help to naturally clean the area surrounding the urethra.
Drink plenty of water. Drinking lots of liquids, especially water will help you urinate more often and get rid of any bacteria that try to camp in your urethra or bladder.
Take good care of your vagina. Check out our 10 Tips for Vaginal Health that will help you keep a healthy vaginal microbiome.
Eat more berries. Adding cranberries, berry juices, or cranberry extract supplements to your diet may help reduce the risk of UTI and contribute to faster healing [30]–[32].

Check your vitamin D levels. Some studies found that vitamin D deficiency may increase the risk of suffering a UTI [33], [34].‍
Consider taking a D-mannose supplement. Studies have shown that D-mannose is effective in reducing UTI symptoms and recurrence, and it can be as effective as antibiotics [35], [36]. If you’re pregnant, ask your provider before taking D-mannose.

References

[1] M. J. Bono and W. C. Reygaert, “Urinary Tract Infection,” in StatPearls, Treasure Island (FL): StatPearls Publishing, 2022. Accessed: Jan. 24, 2022. [Online]. Available: http://www.ncbi.nlm.nih.gov/books/NBK470195/

[2] A. L. Flores-Mireles, J. N. Walker, M. Caparon, and S. J. Hultgren, “Urinary tract infections: epidemiology, mechanisms of infection and treatment options,” Nat. Rev. Microbiol., vol. 13, no. 5, pp. 269–284, May 2015, doi: 10.1038/nrmicro3432.

[3] O. H. Harmanli, G. Y. Cheng, P. Nyirjesy, A. Chatwani, and J. P. Gaughan, “Urinary tract infections in women with bacterial vaginosis,” Obstet. Gynecol., vol. 95, no. 5, pp. 710–712, May 2000, doi: 10.1016/s0029-7844(99)00632-8.

[4] S. H. Sharami, M. Afrakhteh, and M. Shakiba, “Urinary tract infections in pregnant women with bacterial vaginosis,” J. Obstet. Gynaecol. J. Inst. Obstet. Gynaecol., vol. 27, no. 3, pp. 252–254, Apr. 2007, doi: 10.1080/01443610701194846.

[5] L. Hillebrand, O. H. Harmanli, V. Whiteman, and M. Khandelwal, “Urinary tract infections in pregnant women with bacterial vaginosis,” Am. J. Obstet. Gynecol., vol. 186, no. 5, pp. 916–917, May 2002, doi: 10.1067/mob.2002.123987.

[6] M. Medina and E. Castillo-Pino, “An introduction to the epidemiology and burden of urinary tract infections,” Ther. Adv. Urol., vol. 11, p. 1756287219832172, Dec. 2019, doi: 10.1177/1756287219832172.

[7] D. S. Ipe, L. Sundac, W. H. Benjamin, K. H. Moore, and G. C. Ulett, “Asymptomatic bacteriuria: prevalence rates of causal microorganisms, etiology of infection in different patient populations, and recent advances in molecular detection,” FEMS Microbiol. Lett., vol. 346, no. 1, pp. 1–10, Sep. 2013, doi: 10.1111/1574-6968.12204.

[8] J. Schnarr and F. Smaill, “Asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy,” Eur. J. Clin. Invest., vol. 38 Suppl 2, pp. 50–57, Oct. 2008, doi: 10.1111/j.1365-2362.2008.02009.x.

[9] V. Perez-Carrasco, A. Soriano-Lerma, M. Soriano, J. Gutiérrez-Fernández, and J. A. Garcia-Salcedo, “Urinary Microbiome: Yin and Yang of the Urinary Tract,” Front. Cell. Infect. Microbiol., vol. 11, p. 617002, 2021, doi: 10.3389/fcimb.2021.617002.

[10] C. Gottschick et al., “The urinary microbiota of men and women and its changes in women during bacterial vaginosis and antibiotic treatment,” Microbiome, vol. 5, no. 1, p. 99, Aug. 2017, doi: 10.1186/s40168-017-0305-3.

[11] K. Thomas-White et al., “Culturing of female bladder bacteria reveals an interconnected urogenital microbiota,” Nat. Commun., vol. 9, no. 1, p. 1557, Apr. 2018, doi: 10.1038/s41467-018-03968-5.

[12] E. L. Navas-Nacher, F. Dardick, M. F. Venegas, B. E. Anderson, A. J. Schaeffer, and J. L. Duncan, “Relatedness of Escherichia coli colonizing women longitudinally,” Mol. Urol., vol. 5, no. 1, pp. 31–36, 2001, doi: 10.1089/109153601750124285.

[13] A. L. Lewis and N. M. Gilbert, “Roles of the vagina and the vaginal microbiota in urinary tract infection: evidence from clinical correlations and experimental models,” GMS Infect. Dis., vol. 8, p. Doc02, 2020, doi: 10.3205/id000046.

[14] J. R. Brannon et al., “Invasion of vaginal epithelial cells by uropathogenic Escherichia coli,” Nat. Commun., vol. 11, no. 1, p. 2803, Jun. 2020, doi: 10.1038/s41467-020-16627-5.

[15] P. V. Kirjavainen et al., “Abnormal immunological profile and vaginal microbiota in women prone to urinary tract infections,” Clin. Vaccine Immunol. CVI, vol. 16, no. 1, pp. 29–36, Jan. 2009, doi: 10.1128/CVI.00323-08.

[16] G. Dubourg et al., “Deciphering the Urinary Microbiota Repertoire by Culturomics Reveals Mostly Anaerobic Bacteria From the Gut,” Front. Microbiol., vol. 11, p. 513305, 2020, doi: 10.3389/fmicb.2020.513305.

[17] K. L. Nielsen, P. Dynesen, P. Larsen, and N. Frimodt-Møller, “Faecal Escherichia coli from patients with E. coli urinary tract infection and healthy controls who have never had a urinary tract infection,” J. Med. Microbiol., vol. 63, no. Pt 4, pp. 582–589, Apr. 2014, doi: 10.1099/jmm.0.068783-0.

[18] E. Moreno, A. Andreu, T. Pérez, M. Sabaté, J. R. Johnson, and G. Prats, “Relationship between Escherichia coli strains causing urinary tract infection in women and the dominant faecal flora of the same hosts,” Epidemiol. Infect., vol. 134, no. 5, pp. 1015–1023, Oct. 2006, doi: 10.1017/S0950268806005917.

[19] M. Magruder et al., “Gut uropathogen abundance is a risk factor for development of bacteriuria and urinary tract infection,” Nat. Commun., vol. 10, no. 1, p. 5521, Dec. 2019, doi: 10.1038/s41467-019-13467-w.

[20] M. Magruder et al., “Gut commensal microbiota and decreased risk for Enterobacteriaceae bacteriuria and urinary tract infection,” Gut Microbes, vol. 12, no. 1, p. 1805281, Nov. 2020, doi: 10.1080/19490976.2020.1805281.

[21] C. J. Worby et al., “Longitudinal multi-omics analyses link gut microbiome dysbiosis with recurrent urinary tract infections in women,” Nat. Microbiol., vol. 7, no. 5, pp. 630–639, May 2022, doi: 10.1038/s41564-022-01107-x.

[22] D. E. Werter et al., “The Risk of Preterm Birth in Low Risk Pregnant Women with Urinary Tract Infections,” Am. J. Perinatol., Nov. 2021, doi: 10.1055/s-0041-1739289.

[23] R. J. Baer et al., “Risk of Early Birth among Women with a Urinary Tract Infection: A Retrospective Cohort Study,” AJP Rep., vol. 11, no. 1, pp. e5–e14, Jan. 2021, doi: 10.1055/s-0040-1721668.

[24] F. Bánhidy, N. Acs, E. H. Puhó, and A. E. Czeizel, “Pregnancy complications and birth outcomes of pregnant women with urinary tract infections and related drug treatments,” Scand. J. Infect. Dis., vol. 39, no. 5, pp. 390–397, 2007, doi: 10.1080/00365540601087566.

[25] E. Mazor-Dray, A. Levy, F. Schlaeffer, and E. Sheiner, “Maternal urinary tract infection: is it independently associated with adverse pregnancy outcome?,” J. Matern.-Fetal Neonatal Med. Off. J. Eur. Assoc. Perinat. Med. Fed. Asia Ocean. Perinat. Soc. Int. Soc. Perinat. Obstet., vol. 22, no. 2, pp. 124–128, Feb. 2009, doi: 10.1080/14767050802488246.

[26] Y.-K. Chen, S.-F. Chen, H.-C. Li, and H.-C. Lin, “No increased risk of adverse pregnancy outcomes in women with urinary tract infections: a nationwide population-based study,” Acta Obstet. Gynecol. Scand., vol. 89, no. 7, pp. 882–888, Jul. 2010, doi: 10.3109/00016349.2010.486826.

[27] “Screening for Asymptomatic Bacteriuria in Adults: Recommendation Statement,” Am. Fam. Physician, vol. 101, no. 8, pp. 489–492, Apr. 2020.

[28] I. A. Critchley, N. Cotroneo, M. J. Pucci, and R. Mendes, “The burden of antimicrobial resistance among urinary tract isolates of Escherichia coli in the United States in 2017,” PloS One, vol. 14, no. 12, p. e0220265, 2019, doi: 10.1371/journal.pone.0220265.

[29] P. J. Habak and J. Griggs, “Urinary Tract Infection In Pregnancy,” in StatPearls, Treasure Island (FL): StatPearls Publishing, 2022. Accessed: Jan. 20, 2022. [Online]. Available: http://www.ncbi.nlm.nih.gov/books/NBK537047/

[30] D. A. Wing, P. J. Rumney, C. W. Preslicka, and J. H. Chung, “Daily cranberry juice for the prevention of asymptomatic bacteriuria in pregnancy: a randomized, controlled pilot study,” J. Urol., vol. 180, no. 4, pp. 1367–1372, Oct. 2008, doi: 10.1016/j.juro.2008.06.016.

[31] K. C. Maki, K. L. Kaspar, C. Khoo, L. H. Derrig, A. L. Schild, and K. Gupta, “Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection,” Am. J. Clin. Nutr., vol. 103, no. 6, pp. 1434–1442, Jun. 2016, doi: 10.3945/ajcn.116.130542.

[32] L. Stothers, “A randomized trial to evaluate effectiveness and cost effectiveness of naturopathic cranberry products as prophylaxis against urinary tract infection in women,” Can. J. Urol., vol. 9, no. 3, pp. 1558–1562, Jun. 2002.

[33] R. Jorde, S. T. Sollid, J. Svartberg, R. M. Joakimsen, G. Grimnes, and M. Y. S. Hutchinson, “Prevention of urinary tract infections with vitamin D supplementation 20,000 IU per week for five years. Results from an RCT including 511 subjects,” Infect. Dis. Lond. Engl., vol. 48, no. 11–12, pp. 823–828, Dec. 2016, doi: 10.1080/23744235.2016.1201853.

[34] S. Haghdoost, F. Pazandeh, S. Darvish, M. Khabazkhoob, R. Huss, and T. B. Lak, “Association of serum vitamin D levels and urinary tract infection in pregnant women: A case control study,” Eur. J. Obstet. Gynecol. Reprod. Biol., vol. 243, pp. 51–56, Dec. 2019, doi: 10.1016/j.ejogrb.2019.10.015.

[35] L. Domenici et al., “D-mannose: a promising support for acute urinary tract infections in women. A pilot study,” Eur. Rev. Med. Pharmacol. Sci., vol. 20, no. 13, pp. 2920–2925, Jul. 2016.

[36] S. M. Lenger, M. S. Bradley, D. A. Thomas, M. H. Bertolet, J. L. Lowder, and S. Sutcliffe, “D-mannose vs other agents for recurrent urinary tract infection prevention in adult women: a systematic review and meta-analysis,” Am. J. Obstet. Gynecol., vol. 223, no. 2, p. 265.e1-265.e13, Aug. 2020, doi: 10.1016/j.ajog.2020.05.048.