Bladder infection, also called cystitis, refers to infection and inflammation of the urinary bladder. Urethritis is an inflammation of the urethra, which is the passageway that connects the bladder with the exterior of the body. Sometimes cystitis and urethritis are referred to collectively as a lower urinary tract infection, or UTI. Infection of the upper urinary tract involves the spread of bacteria to the kidney and is called pyelonephritis.
The frequency of bladder infections in humans varies significantly according to age and sex. The male/female ratio of UTIs in children younger than 12 months is 4:1 because of the high rate of birth defects in the urinary tract of male infants. In adults, the male/female ratio of UTIs is 1:50. After age 50, however, the incidence among males increases due to prostate disorders.
UTIs are common in females. It is estimated that 50% of adult women experience at least one episode of dysuria (painful urination); half of these patients have a bacterial UTI. Between 2-5% of women's visits to primary care doctors are for UTI symptoms. About 90% of UTIs in women are uncomplicated but recurrent.
UTIs are uncommon in younger and middle-aged men, but may occur as complications of bacterial infections of the kidney or prostate gland.
In children, bladder infection is often caused by congenital (present at birth) abnormalities of the urinary tract. Vesicoureteral reflux is a condition in which the child cannot completely empty the bladder. It allows urine to remain in or flow backward (reflux) into the partially empty bladder.
Causes & symptoms
The causes of bladder infection vary according to gender because of the differences in anatomical structure of the urinary tract.
Most bladder infections in women are so-called ascending infections, which means that they are caused by microbes traveling upward through the urethra to the bladder. The relative shortness of the female urethra (1.2-2 in [3-5 cm] in length) makes it easy for bacteria to gain entry to the bladder and multiply. The most common bacteria associated with UTIs in women include Escherichia coli (about 80% of cases), Staphylococcus saprophyticus, Klebsiella, Enterobacter, and Proteus species. Risk factors for UTIs in women include:
- Sexual intercourse. The risk of infection increases if the woman has multiple partners.
- Use of a diaphragm for contraception.
- An abnormally short urethra.
- Diabetes or chronic dehydration.
- The absence of a specific enzyme (fucosyltransferase) in vaginal secretions. The lack of this enzyme makes it easier for the vagina to harbor bacteria that cause UTIs.
- Inadequate personal hygiene. Bacteria from fecal matter or vaginal discharge can enter the female urethra because its opening is very close to the vagina and anus.
- History of previous UTIs. About 80% of women with bladder infection develop recurrences within two years.
The early symptoms of bladder infection in women are dysuria (pain on urination), urgency (sudden strong desire to urinate), and increased frequency of urination. About 50% of female patients experience fever, pain in the lower back or flanks, nausea and vomiting, or shaking chills. These symptoms indicate pyelonephritis, or spread of the infection to the upper urinary tract.
Most UTIs in adult males are complications of kidney or prostate infections. They usually are associated with a tumor or kidney stones that block the flow of urine and often are persistent infections caused by drugresistant organisms. UTIs in men are most likely to be caused by E. coli or another gram-positive bacterium. S.
saprophyticus, which is the second most common cause of UTIs in women, rarely causes infections in men. The symptoms of bladder infection and pyelonephritis in men are the same as in women. Risk factors for UTIs in men include:
- Lack of circumcision. The foreskin can harbor bacteria that cause UTIs.
- Urinary catheterization. The longer the period of catheterization, the higher the risk of UTIs.
Hemorrhagic cystitis, which is marked by large quantities of blood in the urine, is caused by an acute bacterial or viral infection of the bladder. In some cases, hemorrhagic cystitis is a side effect of therapy or treatment with cyclophosphamide. Hemorrhagic cystitis in children is associated with adenovirus type 11. In some cases, hematuria results from athletic training, particularly in runners.
When bladder infection is suspected, the doctor will first examine the patient's abdomen and lower back, to evaluate pain and unusual enlargements of the kidneys or swelling of the bladder. In small children, the doctor will check for fever, abdominal masses, and a swollen bladder.
The next step in diagnosis is collection of a urine sample. The procedure differs somewhat for women and men. Laboratory testing of urine samples can now be performed with dipsticks that indicate immune system responses to infection, as well as with microscopic analysis of samples. Normal human urine is sterile. The presence of bacteria or pus in the urine usually indicates infection. The presence of blood in the urine (hematuria) may indicate acute UTIs, kidney disease, kidney stones, inflammation of the prostate (in men), endometriosis (in women), or cancer of the urinary tract.
Females patients sometimes require a pelvic examination as part of the procedure to diagnose bladder infections. The patient lies on an obstetrical table with feet in the stirrups. The may take a vaginal culture smear. The patient often is asked to provide a urine sample. A midstream urine sample of 200 ml is collected to test for bladder infection. Often, just a "clean catch," or midstream sample, is needed, without a pelvic exam.
A high bacterial count in the urine sample indicates urethritis. A count of more than 100,000 (105 bacteria CFU/ml, or colony-forming units per milliliter) in the midstream sample indicates a bladder or kidney infection. A colony is a large number of microorganisms that grow from a single cell. Bacterial count can be given in CFU or colony forming units.
In male patients, the doctor will cleanse the opening to the urethra with an antiseptic before collecting the urine sample. The first 10 ml of urine are collected separately. The patient then voids a midstream sample of 200 ml. Following the second sample, the doctor will massage the patient's prostate and collect several drops of prostatic fluid. The patient then voids a third urine specimen for prostatic culture.
A high bacterial count in the first urine specimen or the prostatic specimen indicates urethritis or prostate infections respectively. A bacterial count greater than 100,000 bacteria CFU/ml in the midstream sample suggests a bladder or kidney infection. Children may need to be catheterized (a sterile procedure), in which case a culture of 1,000 bactera CFU/ml is indicative of infection.
Women with recurrent UTIs can be given ultrasound tests of the kidneys and bladder together with a voiding cystourethrogram to test for structural abnormalities. (A cystourethrogram is an x-ray test in which an iodine dye is used to better view the urinary bladder and urethra.) Voiding cystourethrograms are also used to evaluate children with UTIs. In some cases, computed tomography scans (CT scans) can be used to evaluate patients for possible cancers or other masses in the urinary tract.
Dietary changes which may help to control and prevent bladder infection include:
- Drinking 8–12 glasses of water daily helps to wash out bacteria (although this may also dilute antibacterial factors in the urine).
- Acidifying the urine by eating few alkaline foods (dairy, soda, and citrus).
- Following a diet rich in grains, vegetables, and acidifying juices.
- Eliminating foods that irritate the bladder (coffee, black tea, alcohol, and chocolate).
- Eliminating high sugar foods (sweet vegetables, fruits, sugar, and honey).
- Drinking unsweetened cranberry juice to acidify the urine and provide hippuric acid. Cranberry capsules can substitute for the juice.
- Ingesting at least one clove of garlic (or up to 1,200 mg garlic as a tablet) daily for its anti-infective properties.
Herbals and Chinese medicine
Herbals that possess antibacterial, antioxidant, demulcent, astringent, antiviral, antispasmodic, and/or diuretic properties are useful in treating bladder infection. Herb tinctures have a more rapid effect than teas. Useful herbals include bearberry (Arctostaphylos uvaursi), buchu (Barosma betulina), cornsilk (Zea mays), cinnamon, cedar, pipsissewa (Chimaphilia), Oregon grape root (Berberis aquifolia), goldenseal (Hydrastis canadensis), marsh mallow root (Althea officinalis), kava, and birch. A tincture recipe for bladder infection is as follows:
- cornsilk, 2 parts
- bearberry, 2 parts
- Viburnum prunifolium, 1 part
- Valeriana officinalis, 1 part
The patient should take the 5 ml of the tincture three times daily. An infusion of Archillea millefolium should be drunk frequently. The patient can take 1.5–3 g of the Chinese patent medicine Qing Lin Wan (Green Unicorn Pill) twice daily.
The antioxidant vitamins A, C, and E may be beneficial in treating bladder infection. The patient should take 400–600 IU of vitamin E and 300 mg vitamin B6 daily. Ascorbic acid is irritating to the bladder so vitamin C should be taken in the form of calcium ascorbate, about 6,000-20,000 per day. Magnesium may be helpful in treating renal disease. Zinc may boost the immune system.
Homeopathic medicine also can be effective in treating bladder infection. Choosing the correct remedy (based on the patient's symptoms) is always key to the success of homeopathic treatment. Homeopathic remedies for bladder infection include Spanish fly (Cantharis), sarsaparilla, stavesacre (Staphysagria), and Oregon grape (Berberis aquifolium). The correct homeopathic treatment is effective within 12 hours. Acupuncture also can be helpful in treating acute and chronic cases of bladder infection.
Uncomplicated cystitis is treated with antibiotics. These include penicillin, ampicillin, and amoxicillin; sulfisoxazole or sulfamethoxazole; trimethoprim; nitrofurantoin; cephalosporins; or fluoroquinolones. Treatment for women is short-term; most patients respond within three days. In 2003, reports showed that presumed, uncomplicated UTIs in women could often be treated over the telephone when the patient reported her symptoms to a nurse who had a series of prepared questions. Men typically do not respond as well and require seven to 10 days of oral antibiotics for uncomplicated UTIs. Patients of either sex may be given phenazopyridine or flavoxate to relieve painful urination. Trimethoprim and nitrofurantoin are preferred for treating recurrent UTIs in women.
Over 50% of older men with UTIs also suffer from infection of the prostate gland. Some antibiotics, including amoxicillin and the cephalosporins, do not affect the prostate gland. Fluoroquinolone antibiotics or trimethoprim are the drugs of choice for these patients.
A minority of women with complicated UTIs may require surgical treatment to prevent recurrent infections. Surgery is also used to treat reflux problems (movement of the urine backwards) or other structural abnormalities in children and anatomical abnormalities in adult males.
In many cases, alternative medicines can resolve bladder infections quickly. It is important to see a doctor if symptoms do not subside after a few days or worsen. The prognosis for recovery from uncomplicated bladder infection is excellent. However, complicated UTIs in males are difficult to treat because they often involve bacteria that are resistant to commonly used antibiotics.
Researchers are trying to develop a vaccine for UTIs. In 2003, a study of women with frequent infections showed that a vaccine administered by a vaginal suppository headed off bladder infections in many of the study volunteers. The vaccine was still not available on the market, however. The following measures may be taken to prevent bladder infection:
- drinking large amounts of fluid
- reducing intake of sugar
- voiding frequently and as soon as the need arises
Women with two or more UTIs within a six-month period are sometimes given prophylactic antibiotic treatment, usually nitrofurantoin or trimethoprim for three to six months. In some cases the patient is advised to take an antibiotic tablet following sexual intercourse.
Other preventive measures for women include:
- voiding frequently, particularly after intercourse
- proper cleansing of the area around the urethra (wipe front to back)
The primary preventive measure specifically for males is prompt treatment of prostate infections. Chronic prostatitis may go unnoticed but can trigger recurrent UTIs. In addition, males who require temporary catheterization following surgery can be given antibiotics to lower the risk of UTIs.
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