UTI Research

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UTI Research

UTIs can be better understood by analyzing their incidence in women's age groups and other demographics, by their causes, by risk factors for their occurrence, and by treatment forms for women of different ages and circumstances.

Incidence of UTIs in Women by Age Group

  • The 15-19 age group of women has the highest rate of UTIs: about 3.2 percent per 100,000 women.
  • The next highest incidence is in women over 65--about double the rate of other age cohorts (except 15-19).
  • The incidence in women 20-24, 25-29, 30-34, 35-39, 40-44, 45-49, 50-54, 55-59, and 60-64 is just under, at, or over 2 percent per 100,000 women. (The source of this information has a chart depicting the incidence in these 5-year age cohorts.)

Incidence of UTIs in Women by Other Demographics

  • By race: "A retrospective analysis of 24,000 births found the prevalence of UTI during pregnancy to be 28.7 percent in whites and Asians, 30.1 percent in blacks, and 41.1 percent in Hispanics. When socioeconomic status is controlled for, no significant interracial differences seem to exist."
  • By socioeconomic status: It can be inferred from the retrospective study that socioeconomic status is a factor in incidence of UTIs among women, but no specific study was found that focused on this variable.
  • By pregnancy status: In one study that focused on pregnant women, 10 percent of the women "had a diagnosis of a UTI just before or during pregnancy." Another study found that the incidence of UTIs in pregnant women was no different from the incidence in nonpregnant women.
  • By exposure to healthcare: "Healthcare-associated UTIs (HAUTIs) represent the largest subtype among all healthcare-associated infections. The prevalence of HAUTIs assessed in regional studies ranges from 12.9 percent in the US and 19.6 percent in Europe, to up to 24 percent in developing countries."

Common Causes and Risk Factors in Women Contracting UTIs

Causes of UTIs
Risk Factors for UTIs to Occur
  • For premenopausal women: The risk factors include a "history of urinary tract infection, frequent or recent sexual activity, diaphragm contraception use, use of spermicidal agents, increasing parity, diabetes mellitus, obesity, sickle cell trait, anatomic congenital abnormalities, urinary tract calculi, neurologic disorders or medical conditions requiring indwelling or repetitive bladder catheterization".
  • For postmenopausal women: Risk factors include "vaginal atrophy; incomplete bladder emptying; poor perineal hygiene; rectocele, cystocele, urethrocele, or uterovaginal prolapse; lifetime history of urinary tract infection, Type 1 diabetes mellitus". In addition, risk factors include the changes in immune function that come with age, "exposure to nosocomial pathogens, and an increasing number of comorbidities [that] put the elderly at an increased risk for developing infection."
  • For institutionalized older women: Risk factors include "the presence of a urinary catheter and ...history of prior UTI." The "predictive factors include disability in activities of daily living and having a history of urinary incontinence".

Treatments for UTIs in Premenopausal Women

  • Treatment of premenopausal women depends on which of four types of UTI the women are diagnosed with.
  • The four types are: Uncomplicated UTI, Acute uncomplicated cystitis, Acute uncomplicated pyelonephritis, Asymptomatic bacteriuria.
  • Uncomplicated UTI is treated with one of the following antibiotics: "trimethoprim-sulfamethoxozole, ciprofloxacin, nitrofurantoin macrocrystals, nitrofurantoin monohydrate macrocrystals, or fosfomycin tromethamine"
  • Treatment recommendations are changing for uncomplicated acute cystitis. "In the past, uncomplicated acute cystitis has been treated with 7–10 days of antimicrobial therapy. However, recent data have shown that 3 days of therapy" works just as well, and leads to "eradication rates exceeding 90 percent".
  • Acute uncomplicated pyelonephritis: This disease "traditionally has been treated with hospitalization and parenteral antibiotics. However, there has been a recent shift to outpatient management... [with] 14 days of oral or parenteral antibiotics or both ...now standard, with cure rates approaching 100 percent." About 7 percent of cases require hospitalization.
  • UTI recurrences are treated with "continuous prophylaxis with once-daily treatment with nitrofurantoin, norfloxacin, ciprofloxacin, trimethoprim, trimethoprim–sulfamethoxazole, or another agent ...." These drugs have "been shown to decrease the risk of recurrence by 95 percent. This can be continued for 6–12 months and then reassessed."
  • At least two of the antibiotics used to treat UTIs, nitrofurantoin and trimethoprim-sulfamethoxazole, "have been linked to birth defects." These treatments should be avoided for pregnant patients.
  • Nitrofurantoin (brand name Macrobid) is used in 32 percent of UTIs in the US.
  • Trimethoprim-sulfamethoxazole (Bactrim) is a combination of two drugs and is used in 26 percent of UTIs in the US.
  • Fosfomycin (Monurol), a new drug, is taken once, but is expensive and rarely prescribed.
  • Ciprofloxacin (Cipro) is used in 35 percent of uncomplicated UTIs, while levofloxacin is used in 2 percent. These antibiotics can have dangerous side effects.

Treatment of UTIs in Postmenopausal Women

  • The course of treatment for uncomplicated UTI in older women is similar to the treatment for younger women depending on which bacterium is present.
  • Treatment guidelines "recommend nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days, or trimethoprim–sulfamethoxazole 160/800 mg twice daily for 3 days, if local resistance rates do not exceed 20 percent."
  • E. coli (the most common source of UTI infection) has low resistance rates to nitrofurantoin. But "other Enterobacteraciae species, which are more common in older adults, may have intrinsic resistance to nitrofurantoin."
  • Patients who have chronic kidney disease, should not be prescribed nitrofurantoin. Instead, "trimethoprim–sulfamethoxazole should be the preferred empiric oral option for treatment of clinically suspected UTI in older adults."
  • "Fluoroquinolones are among the most prescribed antibiotics for UTI, but resistance to these antimicrobials is high and they should only be used if sensitivity testing is performed."
  • In older women who have had recurrent UTIs, additional measures include prevention strategies. These include "use of antibiotic prophylaxis and nonantimicrobial therapies, such as estrogen replacement therapy and cranberry formulations."
  • "A study by Avorn et al. demonstrated that among women living in nursing homes and assisted living facilities, 10 ounces (300 ml) of cranberry juice cocktail reduced bacteriuria plus pyuria at 6 months of follow-up."

Research Strategy

We located nearly a dozen reports of studies and reviews of study results, but most did not use the age breakdown requested for this research project. Since the raw data was not provided in the reports, we did not attempt to alter the age cohorts cited by the authors to fit them into the format requested. In order to do that with accuracy, we would have needed to use the original datasets.
Sources
Sources

Quotes
  • "Urinary tract infections (UTIs) are the most common outpatient infections, with a lifetime incidence of 50−60% in adult women. "
  • "The prevalence of UTI increases with age, and in women aged over 65 is approximately double the rate seen in the female population overall. Etiology in this age group varies by health status with factors such as catheterization affecting the likelihood of infection and the pathogens most likely to be responsible. In younger women, increased sexual activity is a major risk factor for UTIs and recurrence within 6 months is common. In the female population overall, more serious infections such as pyelonephritis are less frequent but are associated with a significant burden of care due to the risk of hospitalization. "
  • "Key classifications of UTIs Uncomplicated UTI A UTI where there are no relevant functional or anatomical abnormalities in the urinary tract, no relevant kidney function impairment, and no relevant concomitant diseases promoting the UTI or risk of developing serious complications Acute uncomplicated cystitis A lower UTI in which the acute symptoms involve only the lower urinary tract, for example, urgency, painful voiding (dysuria), pollakiuria, and pain above the symphysis Acute uncomplicated pyelonephritis An upper UTI with persistent symptoms including flank pain, flank tenderness, or fever (>38°C) Asymptomatic bacteriuria A positive urine culture (>105 colony-forming units/ml) in the absence of urinary symptoms Recurrent uncomplicated UTIs A recurrent UTI refers to the occurrence of ⩾2 symptomatic episodes within 6 months or ⩾3 symptomatic episodes within 12 months"
  • "With the exception of a spike in young women aged 14−24 years old, the prevalence of UTIs increases with age.2 The prevalence in women over 65 years of age is approximately 20%, compared with approximately 11% in the overall population.3 Between 50% and 60% of adult women will have at least one UTI in their life, and close to 10% of postmenopausal women indicate that they had a UTI in the previous year.4"
  • "Etiology in older postmenopausal women varies depending on their health status, residential status (institutionalized or not), age, the presence of diabetes mellitus, history of/current catheterization, spinal cord dysfunction, and a history of antibiotic use. Most UTIs in noncatheterized older adults are caused by a single bacterial species."
  • " The peak rate of uncomplicated UTIs occurs during the years of maximum sexual activity, usually between the ages of 18 and 39. Uncomplicated recurrent UTIs are also frequent in young women. After a first episode of a UTI, 27% of women have a confirmed recurrence within the next 6 months, and 2.7% have a second recurrence within the same period of time.4"
  • " In women aged 18−49 years, the estimated incidence of pyelonephritis is 28/10,000; 7% of cases require hospital admission"
  • "Uropathogenic Escherichia coli (E. coli) (UPEC) is the dominant infectious agent in both uncomplicated and complicated UTIs. Enterococcus spp. and Candida spp. are substantially more common in complicated infections, while Staphylococcus saprophyticus (S. saprophyticus) is rare (Table 2).5 Infection with UPEC increases the likelihood of recurrence within 6 months.4"
  • "Healthcare-associated UTIs Infectious complications following urological procedures are a major issue, particularly in the context of increasing antimicrobial resistance. Over 4 million patients acquire healthcare-associated infections in the European Union every year, 20−30% of which are considered preventable. Healthcare-associated UTIs (HAUTIs) represent the largest subtype among all healthcare-associated infections. The prevalence of HAUTIs assessed in regional studies ranges from 12.9% in the US and 19.6% in Europe, to up to 24% in developing countries.6–8"
  • "Recurrent UTIs are associated with symptoms of anxiety and depression. The sudden, rapid, and painful onset of a UTI is often a source of anxiety in patients. Feelings of guilt related to a patient’s inability to perform their usual activities, or the impact of recurrent infections on their social activities, may lead to clinical symptoms of depression. The social impact of recurrent UTIs may be particularly marked in premenopausal, working women. "
Quotes
  • "Urinary tract infection and asymptomatic bacteriuria are common in older adults. It is the most frequently diagnosed infection in long-term care residents, accounting for over a third of all nursing home-associated infections [4,5]. It is second only to respiratory infections in hospitalized patients and community-dwelling adults over the age of 65 years [6,7]. As our population ages, the burden of UTI in older adults is expected to grow, making the need for improvement in diagnostic, management and prevention strategies critical to improving the health of older adults."
  • "The incidence of UTI decreases during middle age but rises in older adults [10–12]. Over 10% of women older than 65 years of age reported having a UTI within the past 12 months [11]. This number increases to almost 30% in women over the age of 85 years [12]. "
  • "Risk factors for developing symptomatic UTI in the aging population are different to those in younger women. Age-associated changes in immune function, exposure to nosocomial pathogens and an increasing number of comorbidities put the elderly at an increased risk for developing infection [19]."
  • "Several risk factors associated with UTI in post-menopausal women have been identified, many of which are similar to younger sexually active women. The most consistent and strongest predictor across all age groups is having a history of UTI [10,20,21]. In one study, postmenopausal women with a prior UTI were over four-times more likely to develop a subsequent infection compared with women without a previous diagnosis [20]. In women with over six lifetime UTIs, the risk of developing a subsequent UTI is over seven-times higher than women without a prior history of UTI [10]. Diagnosis of UTI, specifically before the age of 15 years, has also been shown to increase the risk in postmenopausal women, suggesting that genetic factors may predispose certain women to recurrent infections [21]."
  • " Although up to 65% of postmenopausal women report being sexually active [24], most studies have not consistently found intercourse to be a strong predictor for UTI in this population"
  • "Institutionalized adults generally have more functional impairments, higher rates of cognitive deficits and a greater number of medical comorbidities compared with older adults living in the community. All of these characteristics predispose this population to higher rates of ASB and UTI [26]. The most significant risk factors associated with UTI in institutionalized older adults are the presence of a urinary catheter and, similar to community-dwelling older adults, history of prior UTI [3,13,27]."
  • "Other predictive factors include disability in activities of daily living and having a history of urinary incontinence "
  • "UTI is the most common indication for antibiotic prescriptions in older adults. Treatment for uncomplicated UTI in older adults is similar to younger women. The International Clinical Practice Guidelines, updated in 2010 by the Infectious Disease Society of America and the European Society for Microbiology and Infectious Diseases, recommend nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days, or trimethoprim–sulfamethoxazole 160/800 mg twice daily for 3 days, if local resistance rates do not exceed 20% [30]. E. coli has low resistance rates to nitrofurantoin; however, other Enterobacteraciae species, which are more common in older adults, may have intrinsic resistance to nitrofurantoin. In addition, nitrofurantoin is contraindicated in patients with chronic kidney disease, which is more prevalent in older adults. Therefore, trimethoprim–sulfamethoxazole should be the preferred empiric oral option for treatment of clinically suspected UTI in older adults. Local resistance rates, when available, should still primarily influence clinicians empiric antibiotic choices. Fluoroquinolones are among the most prescribed antibiotics for UTI, but resistance to these antimicrobials is high and they should only be used if sensitivity testing is performed [47]."
  • "Prevention strategies for recurrent UTI in postmenopausal women have been studied and include use of antibiotic prophylaxis and nonantimicrobial therapies, such as estrogen replacement therapy and cranberry formulations. Estrogen is thought to play an important role in maintaining a low vaginal pH in pre-menopausal women. As estrogen levels decline in postmenopausal women, the vaginal flora changes and lactobacilli, the predominant flora in younger women, are often absent. This leads to an increase in vaginal pH and promotes colonization of the vagina with uropathogens, such as E.coli [50]. "
  • "A study by Avorn et al. demonstrated that among women living in nursing homes and assisted living facilities, 10 ounces (300 ml) of cranberry juice cocktail reduced bacteriuria plus pyuria at 6 months of follow-up [58]. A major limitation of this study was that participants in the placebo arm of the trial had a higher rate of previous UTI [59]. "
  • "Catheter-associated bacteriuria is the most common infection in both hospitals and long-term care facilities [31,61]"
Quotes
  • "Some antibiotic treatments for urinary tract infections (UTIs), such as nitrofurantoin and trimethoprim-sulfamethoxazole, have been linked to birth defects. The American College of Obstetricians and Gynecologists (ACOG) recommends avoiding these antibiotic treatments in early pregnancy if possible. A study from the Centers for Disease Control and Prevention (CDC) found that about 4 in 10 women with UTIs during early pregnancy filled a prescription for nitrofurantoin or trimethoprim-sulfamethoxazole."
  • "In this study, about 1 in 10 pregnant women had a diagnosis of a UTI just before or during pregnancy."
Quotes
  • "Urinary tract infections are common in infants and young children. About 3% of girls and 1% of boys will have a UTI by 11 years of age. Urinary tract infections are also common in female adolescents and young women; young women develop UTIs at more than 3 times the rate of young men"
  • "Treatment of a UTI is with antibiotics to eliminate the bacteria. "
  • "Girls as well as young women are particularly susceptible to UTIs because their urethras are shorter so germs from the bowel can pass along this route to the bladder. To prevent UTIs, girls should always wipe from front to back with toilet paper after bowel movements. Adolescent females who are menstruating should change tampons and sanitary napkins frequently. Since bubble baths and perfumed soaps can irritate the genitals and urethra, girls should avoid contact with these substances. Some foods and beverages can cause bladder irritation such as colas, caffeinated drinks, chocolate, and some spices. If your child has any of the symptoms of a UTI listed above, contact your pediatrician."
Quotes
  • "UTIs in women are very common; approximately 25-40% of women in the United States aged 20-40 years have had a UTI. UTIs account for over 6 million patient visits to physicians per year in the United States. Approximately 20% of those visits are to EDs."
  • "The largest group of patients with UTI is adult women. The incidence of UTI in women tends to increase with increasing age. Several peaks above baseline correspond with specific events, including an increase in women aged 18-30 years (associated with coitus—so-called honeymoon cystitis—and pregnancy)."
  • "Rates of infection are high in postmenopausal women because of bladder or uterine prolapse causing incomplete bladder emptying; loss of estrogen with attendant changes in vaginal flora (notably, loss of lactobacilli), which allows periurethral colonization with gram-negative aerobes, such as E coli; and higher likelihood of concomitant medical illness, such as diabetes."
  • "Younger patients have the lowest rates of morbidity and mortality. Factors associated with an unfavorable prognosis include the following: Old age General debility Renal calculi or obstruction Recent hospitalization Urinary tract instrumentation or antibiotic therapy Diabetes mellitus Chronic nephropathy Sickle cell anemia Underlying cancer Intercurrent chemotherapy"
Quotes
  • "Data show that females ages 15-19 have the highest incidence of uncomplicated UTIs compared to another age group. According to Dr. Wyman, it can be related to the first sexual contact. However, acute cases of UTIs decline over the years."
  • "Recurrent UTIs are highest in females of 15-19 and women over 65 years of age. Annual incidence declines over the years in all age groups."
Quotes
  • "As the most frequently seen infectious disease, CAUTIs affect more than 150 million people annually. Complicated UTIs in particular constitute a huge burden on healthcare systems as a frequent reason for hospitalization. The prevalence of HAUTIs ranges between 1.4% and 5.1%, and the majority of them are catheter-related UTIs. Community-onset HAUTIs have gained importance in recent years."
Quotes
  • "An estimated 11% of U.S. women report at least one physician-diagnosed urinary tract infection (UTI) per year, and the lifetime probability that a woman will have a UTI is 60%"
  • " More than one half of women will have at least one UTI during their lifetime 1, and 3–5% of all women will have multiple recurrences 4."
  • "Although UTIs are caused by many species of microorganisms, most (80–90%) are caused by uropathogenic Escherichia coli (predominantly O, K, and H antigen serotypes)"
  • "The remaining 10–20% of UTIs are caused by other microorganisms, occasionally colonizing the vagina and periurethral area 1 4 5 6. Staphylococcus saprophyticus frequently causes lower UTIs and has been isolated in 3% of nonpregnant, sexually active, reproductive-aged women with pyelonephritis"
  • "Proteus, Pseudomonas, Klebsiella, and Enterobacter species all have been isolated in women with cystitis or pyelonephritis, and these frequently are associated with structural abnormalities of the urinary tract, indwelling catheters, and renal calculi"
  • "Risk Factors For Urinary Tract Infection in Premenopausal and Postmenopausal Women Premenopausal Women History of urinary tract infection Frequent or recent sexual activity Diaphragm contraception use Use of spermicidal agents Increasing parity Diabetes mellitus Obesity Sickle cell trait Anatomic congenital abnormalities Urinary tract calculi Neurologic disorders or medical conditions requiring indwelling or repetitive bladder catheterization Postmenopausal Women Vaginal atrophy Incomplete bladder emptying Poor perineal hygiene Rectocele, cystocele, urethrocele, or uterovaginal prolapse Lifetime history of urinary tract infection Type 1 diabetes mellitus"
  • "In the past, uncomplicated acute cystitis has been treated with 7–10 days of antimicrobial therapy. However, recent data have shown that 3 days of therapy is equivalent in efficacy to longer duration of therapy, with eradication rates exceeding 90%"
  • "Treatments: Trimethoprim-sulfamethoxozole, Ciprofloxacin, Nitrofurantoin macrocrystals, Nitrofurantoin monohydrate macrocrystals, Fosfomycin tromethamine"
  • "Acute pyelonephritis traditionally has been treated with hospitalization and parenteral antibiotics. However, there has been a recent shift to outpatient management, when possible.... 14 days of oral or parenteral antibiotics or both is now standard, with cure rates approaching 100%."
  • "Recurrent UTIs are common in women, occurring in up to 25–50% within 1 year of initial infection. known risk factors associated with recurrence. These include frequent intercourse, long-term spermicide use, diaphragm use, a new sexual partner, young age at first UTI, and a maternal history of UTI."
  • "For women with frequent recurrences, continuous prophylaxis with once-daily treatment with nitrofurantoin, norfloxacin, ciprofloxacin, trimethoprim, trimethoprim–sulfamethoxazole, or another agent listed in Table 1 has been shown to decrease the risk of recurrence by 95% 4. This can be continued for 6–12 months and then reassessed."
  • "Antimicrobial therapy for UTIs in postmenopausal women is influenced by a number of factors. The organisms causing UTIs in this population differ from the causative agents in younger women. Staphylococcus saprophyticus rarely is isolated; however, gram-negative bacteria and enterococci are common (E coli remains the most common causative organism). ... few studies have adequately evaluated treatment options in these women. ...3–6 days of antibiotic treatment was equivalent to longer courses of treatment (7–14 days), with fewer adverse events"
Quotes
  • "A retrospective analysis of 24,000 births found the prevalence of UTI during pregnancy to be 28.7% in whites and Asians, 30.1% in blacks, and 41.1% in Hispanics. When socioeconomic status is controlled for, no significant interracial differences seem to exist."
  • "A survey-based analysis of self-reported UTI found similar trends. This study also considered Native American women and found the highest prevalence of UTI in this population (24.2%) as compared with Asian (10.3%), white (16.6%), Hispanic (18.3%), and black (20.3%) women. [15]"
  • "The frequency of urinary tract infection (UTI) in pregnant women (0.3-1.3%) is similar to that in non-pregnant women. [10] However, recurrent bacteruria is more common in pregnant women than non-pregnant women. Changes in coital patterns (eg, position, frequency, postcoital antibiotics) can offset recurrence in at-risk individuals. "
Quotes
  • "In premenopausal women, coitus, spermicide exposure, prior history of UTI, and recent antibiotic exposure have been identified as key risk factors for UTI in both case-control and prospective studies. Spermicide exposure likely modifies the normal vaginal flora via a differential antimicrobial effect so as to eradicate the normal introital flora and enhance E. coli colonization. These same factors appear to be important in recurrent infection in young women, as do two additional factors, namely a maternal history of UTI or a history of childhood onset ofUTI. "
  • "In postmenopausal women, the predominant factors associated with recurrent UTI are anatomic or functional defects, such as incontinence, post-void residual urine, or cystocele. Nonsecretor status and prior history of UTI, as in younger women, are both related to recurrent UTI in postmenopausal women. Last, the relative lack of estrogen accompanying menopause results in a loss of the normal lactobacillus-dominant vaginal flora, an elevated vaginal pH, increased introital colonization with E. coli, and increased UTI. Topical estrogen can reverse these changes and greatly reduce the incidence of recurrent UTI in postmenopausal women not using hormone replacement therapy [17]"
Quotes
  • "Health care providers usually pick from one of three antibiotics for uncomplicated UTIs (UTIs in the lower urinary tract of non-pregnant, premenopausal women). Nitrofurantoin (brand name Macrobid): This drug is used in 32% of UTIs in the United States. Trimethoprim-sulfamethoxazole (Bactrim): This combination of two drugs is used in 26% of UTIs in the United States. Fosfomycin (Monurol): This newer drug only has to be taken one time, but it's expensive and rarely prescribed. . Ciprofloxacin (Cipro) is used in 35% of uncomplicated UTIs, while levofloxacin is used in 2%. These antibiotics can be important treatments in some cases of more complicated UTIs, but can have dangerous side effects."
  • " Studies have found that 25-42% of women are able to recover from an uncomplicated UTI without antibiotics. But that means a majority of UTIs do not go away on their own. If left untreated, they can lead to continued discomfort and other more serious health issues, such as kidney damage or a severe infection. Therefore, treatment is recommended."