Managing Urinary Tract and Vaginal Infections
Susan W. Ryan, DOTHE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 7 - JULY 96
In Brief: Urinary tract infections (UTIs) and vaginitis are common among women. UTIs are classified as either complicated or uncomplicated, and, in most cases, the diagnosis can be made from the history and a urinalysis. Changes in the types of antibiotics available and the length of treatment have had promising results. Vaginitis infections are usually candidiasis, bacterial vaginosis, or trichomoniasis, all of which can be diagnosed from the history and microscopic evaluation of the discharge. Both over-the-counter and prescription medications are used in treatment. Patient education about prevention measures can lessen infection risk.
Dysuria and vaginal discharge, itching, or irritation are some of the most frequent complaints physicians hear from their female patients. These are the signs and symptoms of urinary tract and vaginal infections. By obtaining a detailed history, physicians can clarify which type of infection the patient has—or rule out other underlying conditions—and determine the best treatment path.
Urinary Tract Infections
Acute urinary tract infections (UTIs) affect up to 20% of women during their lifetime (1). UTIs are often classified by the site of infection or by designating them as either complicated or uncomplicated. Complicated UTIs are those accompanied by underlying conditions such as diabetes, pregnancy, a compromised immune system, or anatomic abnormalities that can interfere with the normal response to treatment. This distinction is often the basis for selecting antibiotics as well as for prognostic implications. The diagnosis and treatment of complicated UTIs, however, is beyond the scope of this article.
Uncomplicated UTIs make up the majority of cases. In addition to dysuria, women commonly complain of urinary urgency, frequency, and hesitancy. Occasionally, there are complaints of suprapubic or low-back pain as well as hematuria. More severe symptoms, or those accompanied by fever and chills or nausea and vomiting, reflect a more complicated infectious process.
Certain risk factors may determine the extent of the physical examination as well as the treatment plan. For example, a history of recent UTIs and frequent or vigorous sexual activity increases the likelihood of infection. Underlying anatomic abnormalities of the urinary tract, such as strictures, calculi, or reflux, can also predispose a woman to infections.
Patient workup. Because the causative agents for UTIs and their response to antibiotics are so well established, an abbreviated workup is adequate in many cases. There is ample evidence (2,3) advocating a urinalysis and empiric treatment for uncomplicated UTIs.
The urinalysis done in the office is a valuable tool in identifying the infection. Leukocyte esterase testing on the dipstick has a reported sensitivity of 75% to 96% in detecting pyuria associated with infection (4), even though some false positives occur. The nitrate dipstick is also helpful in detecting bacteriuria, but a small percentage can be missed.
Routine urine cultures, while often done, are considered to be of minimal value. Most selections for antibiotics are done empirically before results are available from cultures. Urine cultures should be reserved for complicated or unclear cases.
When evaluating a woman who has dysuria, it is important to consider whether a sexually transmitted disease (STD) is the cause. Concurrent vaginal symptoms and urinary complaints in a sexually active woman must raise the physician's suspicion for an STD. Urinalysis and microscopic examination of the vaginal discharge, along with examination of the cervix, will narrow the possibilities. Cultures for gonorrhea and chlamydia should be obtained when indicated.
The organisms most likely to be responsible for UTIs are gram-negative bacteria, specifically Escherichia coli in 80% of cases (1). Staphylococcus saprophyticus and Proteus mirabilis account for most of the remaining infections. Selection of antimicrobial agents should be based on susceptibility of these species to a particular drug.
Treatment choices. While amoxicillin has been a first choice in the past, other drugs now offer better susceptibility profiles. Changes have recently been recommended in the duration of therapy as well (5). Three-day regimens appear to be ideal becaise they have comparable efficacy with far fewer side effects and complications1 than the previously standard 7- to 10-day course. Acceptable drug choices include double-strength trimethoprim with sulfamethoxazole twice a day for 3 days or a fluoroquinolone such as ciprofloxacin 250 mg twice a day or norfloxacin 400 mg twice a day. Alternative oral regimens include cephalosporins, amoxicillin with potassium clavulanate, and nitrofurantoin (6). All selections for an antibiotic must take into account patient allergies, drug formulary requirements, and the cost to the patient.
Recurrent UTIs may indicate reinfection or, rarely, anatomic abnormalities that prevent the complete eradication of an organism (5). In these cases, obtaining a culture after treatment can demonstrate a cure. If anatomic abnormalities are suspected, a referral to a urologist may be indicated. For some women, recurrent UTIs may follow intercourse. Treatment choices in these cases include continuous prophylaxis, patient-initiated treatment (see "Bladder and 'Yeast' Infections: Prevention and Cure"), and postcoital prophylaxis. There is good evidence (7) that the use of single-dose antibiotics for postcoital prophylaxis does not encourage development of resistant strains.
Vaginitis is another common infection, one that most women will encounter in their lifetime. The three typical infections that account for most cases of vaginitis are candidiasis, bacterial vaginosis, and trichomoniasis. While these causes of vaginitis are not limited to athletic women, their symptoms may be severe enough to curtail some activities.
The evaluation of a woman with suspected vaginitis should be directed at obtaining details about her symptoms. The predominant symptoms are an abnormal discharge and pruritus. Specific details regarding the nature of this discharge must be uncovered, along with information about sexual activity, current or recent medications, previous infections, and any related urinary complaints.
In addition to an exhaustive history, a directed physical examination with microscopic evaluation of the discharge is necessary. Slide mounts should be carried out with both normal saline and 10% potassium hydroxide (KOH) preparations. Litmus testing for pH provides additional information in confirming the diagnosis.
Candidiasis. Vaginal candidiasis, often referred to as a yeast infection, is the most common cause of vaginitis, and is caused mostly by the species Candida albicans. Several other candidal species, such as C tropicalis, tend to be associated with more resistant or recurrent infections. The classic symptoms include vulvar and vaginal itching, along with a white, cottage-cheese-like discharge. There are a few predisposing factors, such as a recent course of antibiotics, use of oral contraceptives, pregnancy, diabetes, and possibly increased dietary sugars or milk products. These conditions change local bacterial flora or host resistance. While candidiasis is not considered an STD, sexual activity can precipitate this condition or enhance the possibility of recurrence.
While obtaining discharge samples for microscopic evaluation from the vagina, pH testing can be done. The pH of normal vaginal fluid ranges from 3.8 to 4.2, and variations from this can be helpful in establishing the diagnosis. In candidal infections, the pH is usually normal or as high as 4.5. Microscopic observation of the discharge is made on a slide preparation with 10% KOH solution. Demonstration of pseudohyphae or spores is usually necessary to confirm the diagnosis. Cultures are available and, though sensitive in identifying the species, are usually reserved for difficult cases.
Many women will try home remedies in an effort to control their symptoms (see "Bladder and 'Yeast' Infections: Prevention and Cure"). In addition, there are numerous effective preparations available over the counter that both patients and physicians have trusted for years. These typically are topical antifungals used for 1-week periods. However, the introduction of oral triazole antifungals has dramatically changed the treatment of candidal infections. Fluconazole has been used for years and recently gained approval from the US Food and Drug Administration for this use. It is given orally as a one-time dose of 150 mg to cure vaginal candidiasis. This class of drugs has obvious appeal because of increased compliance.
Women who suffer from recurrent candidal infections may be more intolerant to disruptions in their vaginal flora and perhaps harbor more virulent strains of Candida. These patients should be counseled about their predisposing risk factors and advised about prevention measures, such as avoiding frequent douching, avoiding feminine sprays and perfumes, and promptly changing out of damp underwear or workout clothes.
Bacterial vaginosis. The second most common type of vaginal infection is bacterial vaginosis. In the past it has been called Gardnerella vaginalis or Haemophilus vaginalis as well as nonspecific vaginosis. It is now considered to represent an overgrowth of aerobic and anaerobic bacteria. There is some controversy regarding the possible contributing role of sexual partners and intrauterine devices in this infection.
The patient's chief complaint will be a malodorous discharge, in contrast to the extreme itching of candidiasis. This discharge is characterized as being homogenous and gray with a fishy odor. On occasion, it may be frothy.
The diagnosis can be readily made by (1) detecting clue cells on a wet mount and (2) measuring a pH between 5 and 5.5. Clue cells are epithelial cells with a stippled or granulated appearance. The "whiff test," which is sometimes performed, refers to the discharge's transient fishy or amine odor when exposed to KOH solution.
The treatment of choice for bacterial vaginosis is metronidazole. It is either given orally as 500-mg tablets twice a day for 7 days or as a vaginal gel, 5 g twice a day for 5 days. Some studies have shown (8) that a single 2-g oral dose can be as effective as the 5- to 7-day courses, but the Centers for Disease Control and Prevention (CDC) guidelines still recommend the twice-a-day course. Patients taking metronidazole must be cautioned against drinking alcohol during and 48 hours after treatment because of the well-established disulfiramlike reaction. An alternative to metronidazole is clindamycin either as 300 mg orally twice a day or as an intravaginal cream, 5 g once daily for 5 to 7 days. Treatment of the sexual partner is not necessary unless he has balanitis.
Trichomonas vaginitis. Trichomonas vaginalis, an anaerobic protozoan that is found in the genitourinary tract, can infect both men and women. It is considered an STD that often goes untreated because it is an infection that is largely asymptomatic. In fact, some 50% of infected women and 90% of infected men are asymptomatic (9). Because it is quite common for patients to have concurrent STDs, it is important to evaluate the patient for these as well, and to treat as necessary.
Women who are symptomatic typically note this condition around the time of menstruation. The obvious symptom is a discharge that at times can be copious and frothy. Though it is often taught that the discharge is green in color, it is usually gray. The odor of trichomonas vaginitis is very offensive. Vulvovaginal irritation and edema along with dysuria are seen in about half of patients. Less commonly, a "colpus macularis" or strawberry cervix is noted on physical examination.
The diagnosis of this infection may be difficult. The pH of the discharge is greater than 5.0, but the wet mount findings can be elusive. This test consists of identifying motile trichomonads with a normal saline preparation, and it is affected by a number of variables such as air cooling and the amount of inoculum on the slide. In the majority of clinically significant cases, an adequate number of organisms is available for identification. Newer immunological tests are available for trichomonas, but currently they cannot be used in the primary care setting. Therefore, on occasion, treatment is started on a presumptive basis.
Sexual partners need to be treated simultaneously with metronidazole. This is usually given as a 2-g single dose. For alternative dosing, treatment failures, or recurrences, the dosage should be 500 mg twice a day for 5 to 7 days. In pregnancy, clotrimazole should be used, but it has a significantly lower cure rate.
UTIs and vaginitis will probably always plague some women. But physicians can use detailed histories and careful in-office testing to confirm the diagnosis, and can rely on many new treatments that offer quick and successful cures. Physicians can also educate patients about prevention measures that will reduce their risk of infection.
Dr Ryan is in private practice at The Denver Center for Sports and Family Medicine in Denver and is a team physician for the University of Denver and USA Wrestling. She is a member of the American College of Sports Medicine. Address correspondence to Susan W. Ryan, DO, The Denver Center for Sports and Family Medicine, 210 University Blvd, Suite 210, Denver, CO 80206.