VAGINITIS
Vaginitis
Most common gynecologic diagnosis in the primary care setting. In approximately 90 % of affected women, occurs secondary to bacterial vaginosis, Vulvovaginal candidiasis or Trichomoniasis. Develops when the vaginal flora has been altered by introduction of a pathogen or by changes in the vaginal environment that allow pathogens to proliferate. The evaluation of vaginitis requires a directed history and physical examination, with focus on the site of involvement and the characteristics of the vaginal discharge. The laboratory evaluation includes : microscopic examination of a saline wet-mount preparation a potassium hydroxide preparation, a litmus test for the pH of vaginal secretions a "whiff" test.
Epidemiology:
The prevalence and causes of vaginitis -uncertain, in part because the condition is so often self-diagnosed and selftreated. It is frequently asymptomatic or has more than one cause. Most experts believe that up to 90 percent of vaginitis cases are secondary to bacterial vaginosis, vulvovaginal candidiasis and trichomoniasis. Noninfectious causes include vaginal atrophy, allergies and chemical irritation.
Bacterial Vaginosis:
In the United States, is currently the most common cause of Vaginitis, with 40 to 50 % of cases in women of childbearing age Caused by proliferation of a number of organisms, including Gardnerella vaginalis, Mobiluncus species, Mycoplasma hominis and Peptostreptococcus species. Determining the prevalence of bacterial vaginosis is difficult because one third to three quarters of affected women are asymptomatic. Found in 15 to 19 % of ambulatory gynecology patients, 10 to 30 % of pregnant patients and 24 to 40 % of patients in sexually transmitted disease clinics.
Vaginal Flora
BV has been shown to be a risk factor for acquiring HIV, gonorrhea, and HSV-2. BV is a common cause of vaginal symptoms putting a large number of women at a higher risk for acquiring HIV than women with normal flora.
Women with normal flora benefit from the bi-products of Lactobacillus. – Lactic acid helps maintain a low vaginal pH. Hydrogen peroxide in vitro inhibits HIV. Women colonized with H2O2 producing Lactobacillus are less likely to have a shift in flora.
Pathophysiology:
The normal physiologic vaginal discharge comprises vaginal secretions, exfoliated cells and cervical mucus. The frequency of vaginal discharge varies with age, menstrual cycle, pregnancy and use of oral contraceptives. The normal vaginal environment is characterized by a dynamic interrelationship between Lactobacillus acidophilus and other endogenous flora, estrogen, glycogen, vaginal pH and metabolic by-products of flora and pathogens. L. acidophilus produces hydrogen peroxide, which is toxic to pathogens and keeps the healthy vaginal pH between 3.8 and 4.2.
Vaginitis occurs because the vaginal flora has been altered by the introduction of pathogens or changes in the vaginal environment that allow pathogens to proliferate. Antibiotics, contraceptives, sexual intercourse, douching, stress and hormones can change the vaginal environment and allow pathogens to grow. In bacterial vaginosis, it is believed that some inciting event decreases the number of hydrogen peroxide-producing L. acidophilus organisms. The resultant change in pH allows proliferation of organisms that are normally suppressed, such as G. vaginalis, M. hominis and Mobiluncus species.
These organisms produce metabolic byproducts, such as amines, that further increase the vaginal pH and cause exfoliation of vaginal epithelial cells.
The amines are also responsible for the characteristic malodorous discharge in bacterial vaginosis. Similarly, changes in the vaginal environment, such as an increase in glycogen production in pregnancy or altered estrogen and progesterone levels from the use of oral contraceptives, enhance the adherence of C. albicans to vaginal epithelial cells and facilitate the germination of yeast. These changes may transform asymptomatic colonization into symptomatic infection In patients with trichomoniasis, changes in estrogen and progesterone levels, as well as elevations of vaginal pH and glycogen levels, may enhance the growth and virulence of T. vaginalis.
Methods for Diagnosis of Bacterial Vaginosis
1. Clinical Diagnosis, Amsel criteria This will be used to clinically manage patients 2. Gram stain, Nugent score Centralized and standardized lab based method Standard for clinical trails Not used for clinical management
Clinical Diagnosis
Must have 3 of the 4 signs for a diagnosis of BV Discharge, white & homogeneous Elevated pH, >4.5 Amine odor present 20% clue cells present on wet mount
Specimen Collection
Swab the lateral or posterior fornices of the vagina Place the swab in a sterile tube containing 6 drops of saline To assure the consistency of the volume of saline the lab should provide the clinic with the saline tubes. Transfer to the lab ASAP.
Clinical Diagnosis
1. Discharge White & homogeneous Limitations: douching or cleansing prior to exam, small amount of discharge Use of microbicide or placebo gels may make evaluation of discharge more difficult.
Clinical Diagnosis
2. pH of vaginal fluid Use S/P pH Indicator Strips Range 3.6 to 6.1 Touch the strip to the wall of the vagina or use a swab of the vagina to moisten the pH paper. Avoid the cervical mucus, which has a higher pH than the vagina. Compare the color to the chart on the container. pH >4.5 is consistent with BV Limitations: blood, sperm, and cervical mucus can elevate the pH; acid gels may lower the pH.
Clinical Diagnosis
3. Amine odor KOH prep Transfer a small amount of the vaginal fluid onto a slide. Add 1 drop of 10% KOH to one of the slides. A fishy odor indicates the presence of amines. Limitation: technologist may not be able to smell the odor. Cover slip the slide and read for budding yeast and pseudohyphe.
Clinical Diagnosis
4. Wet Mount Adhere a label on the slide. Transfer a small amount of the vaginal fluid onto a slide. Add a drop of saline if there isn’t enough fluid and mix. Cover slip the slide.
Clinical Diagnosis
Initially, read at 10X for Trichomonas and yeast. Scan the whole coverslip for Trichomonas Read the epithelial cells at 40X to determine if clue cells. For the study there must be 20% clue cells to be positive for clue cells. WBC are not recorded for the study, but may be requested by the clinician. Limitations: Presence of gel may interfere with observation. Important to read for Trichomonas within 1 hour.
Evaluation:
A patient who complains of vaginal discharge, itching, frequent urination and/or irritation should be evaluated for vaginitis . The first step is to obtain a directed history. The patient should be asked about specific symptoms and their duration, any previous diagnosis and previous treatment and its effects. A general medical review, dermatologic review, social history and contraceptive history can also be helpful.
Diagnosis of Vaginitis: Evaluation of patients with suspected vaginitis.
Diagnosis of Vaginitis:
It is important to inquire about abdominal or pelvic pain, fever, recurrent or resistant infections, urinary symptoms, menstrual history, pregnancy and sexual practices. The nature of the discharge (i.e., amount, consistency, color, odor, accompanying pruritus) may also provide important clues. Dysuria is a common symptom of vaginitis. It is usually external and is defined as pain and burning when urine touches the vulva. In contrast, internal dysuria, defined as pain inside the urethra, is usually a sign of cystitis.
Microscopic examination of a wet-mount preparation can also detect "clue cells," which are vaginal epithelial cells that are coated with the coccobacilli. When a skilled examiner performs the search for clue cells, examination of wet-mount preparations can have a sensitivity of 60 percent and a specificity of up to 98 percent for the detection of bacterial vaginosis. The examination may also detect fungal hyphae, increased numbers of polymorphonuclear cells
KOH Preparation and Whiff Test:
A second specimen of the vaginal discharge should be placed on a slide with a 10 percent KOH solution. This is useful for detecting candidal hyphae, mycelial tangles and spores. The test is positive in 50 to 70 percent of women with candidal infection. During preparation of the KOH slide, a whiff test can be performed. The whiff test is positive if a "fishy" or amine odor is detected when KOH is added to the vaginal discharge. The odor results from the liberation of amines and organic acids produced from the alkalization of anaerobic bacteria. A positive whiff test is suggestive of bacterial vaginosis
Whiff test for amines:
Litmus Testing for Ph: The pH level can be determined by placing litmus paper in the pooled vaginal secretions or against the lateral vaginal wall. The color is then compared to the colors and corresponding pH values on a standard chart. A normal vaginal pH is between 3.8 and 4.2. Blood and cervical mucus are alkaline and alter the pH of a vaginal sample. A pH greater than 4.5 is found in 80 - 90 % patients with bacterial vaginosis and frequently in patients with trichomoniasis. Differential Diagnosis: The diagnosis of vaginitis is based on the patient's symptoms, the physical examination, the findings of microscopic examination of the wet-mount and KOH preparations, and the results of the pH litmus test.
Amsel's Diagnostic Criteria for Bacterial Vaginosis:
Thin, homogeneous discharge Positive "whiff" test "Clue cells" present on microscopy Vaginal pH >4.5 Three of four criteria must be met. Establishes accurate diagnosis of bacterial vaginosis in 90 % affected women. Highly significant criterion.
Spiegel's Diagnostic Criteria for Bacterial Vaginosis Normal: Gram stain shows a predominance of Lactobacillus acidophilus (3+ or 4+), with or without Gardnerella vaginalis. Bacterial vaginosis: Gram stain shows mixed flora (grampositive, gram-negative or gram-variable bacteria) and absent or decreased L. acidophilus (zero to 2+). A. L. acidophilus (large gram-positive bacilli) B. G. vaginalis (small gram-variable rods) Scoring for each of the above bacterial morphotypes: Zero = No morphotypes per oilimmersion field 1+ = Less than one morphotype per oil-immersion field 2+ = One to five morphotypes per oil-immersion field 3+ = Six to 30 morphotypes per oil-immersion field 4+ = More than 30 morphotypes per oil-immersion field I
Bacterial vaginosis:
Clue cells in bacterial vaginosis:
Gram Stain for Diagnosing BV
Based on the quantity of 3 morphotypes Lactobacilli, Gram variable rods, and curved rods Sensitivity 86%-89% and specificity 94%-96% compared to Amsel criteria
Scoring of Gram Stain Slides are scanned on 10X to evaluate the quality of the smear. (Must have epithelial cells) Bacterial morphotypes are quantitated.
Quantitation of Bacterial Morphotypes 0-1/ 1000X magnification=1+ 1-4/ 1000X magnification=2+ 5-30/ 1000Xmagnification=3+ >30/ 1000Xmagnification=4+ Read at least 5 nonconsecutive fields and average the quantity of morphotypes.
Nugent Scores of Gram Stain Morphotype 4+ Lactobacilli 3+Lactobacilli 2+Lactobacilli 1+Lactobacilli 0 Lactobacilli 1+Gardnerella/Ana GNR 2+Gardnerella/Ana GNR 3+Gardnerella/Ana GNR 4+Gardnerella/Ana GNR 1-2+ Mobiluncus 3-4+ Mobiluncus
Points 0 1 2 3 4 1 2 3 4 1 2
Nugent Scores of Gram Stain
Points are added according to the morphotypes seen. Total will be between 0 and 10 0-3 Normal 4-6 Intermediate 7-10 bacterial vaginosis
Vulvovaginal Candidiasis
Second most common cause of vaginitis in the United States &most common cause in Europe. An estimated 75 % women have vulvovaginal candidiasis at some time in life, and 5 % of women have recurrent episodes. Candida albicans is the infecting agent in 80 -90% of patients. Recently, the frequency of non-albicans species (e.g., Candida glabrata) has increased, possibly secondary to greater use of over-the-counter antifungal products.
Risk factors for uncomplicated vulvovaginal candidiasis have been difficult to determine. Studies have shown that the risk of this infection is increased in women who use oral contraceptive pills, a diaphragm and spermicide, or an IUD. Other risk factors include young age at first intercourse, intercourse more than four times per month and receptive oral sex. The risk of vulvovaginal candidiasis is also increased in some women who have diabetes, are pregnant or are taking antibiotics.
Establishing Candida species as the cause of vaginitis can be difficult because as many as 50 % asymptomatic women have candidal organisms as part of their endogenous vaginal flora. Candidal organisms are not transmitted sexually, and episodes of vulvovaginal candidiasis do not appear to be related to the number of sexual partners. Recurrent vulvovaginal candidiasis is defined as four or more episodes in a one-year period. It is not clear whether recurrences are secondary to predisposing and/or precipitating factors, sexual transmission, intestinal reservoir or vaginal persistence.
Trichomoniasis
A motile organism with four flagella, Is the third most common cause of Vaginitis. It affects 180 million women worldwide and accounts for 10 - 25 % of vaginal infections. Transmitted sexually and identified in 3080% of the male sexual partners of infected women. Trichomoniasis is associated with and may act as a vector for other venereal diseases. Studies indicate that this infection increases the transmission rate of the human immunodeficiency virus.
Trichomoniasis
Caused by protozoan parasite Very common in women Often mixed infection with other STD's Men are often carriers--asymptomatic (10% may have penile discharge) themselves, but may carry infection to female sexual partners Women may have recurrent Trichomonas infections, almost always due to reinfection by a sexual partner, therefore should treat both partners Possible (not very likely) to get from warm wet infected environmental contact, like locker room bench, toilet, or infected clothing More often transferred by sexual contact Incubation period--four weeks
Location of infection In women, Vaginitis, cervicitis, urethritis may move to bladder In men, urethritis may move to prostate and seminal vesicles Symptoms In women, heavy foamy yellow-gray foulsmelling vaginal discharge, itching, rash, lower abdominal pain, painful intercourse In men, (if any symptoms) white discharge, itching
Diagnosis: observation of discharge, culture (5 days), microscopic observation Treatment Flagyl (metronidazole) for seven days Should not be given to pregnant or nursing women Side effects include nausea and vomitting, headaches, alcohol intolerance Must treat both partners
Risk factors for trichomoniasis include use of an IUD, cigarette smoking and multiple sexual partners. From 20 – 50% of women with trichomoniasis are asymptomatic. Trichomoniasis may be associated with premature rupture of membranes and preterm delivery. Sexual partners should be treated and instructed to avoid sexual intercourse until both partners are cured.