Office Laboratory Diagnosis of Vaginitis Clinician-Performed Tests Compared with a Rapid Nucleic Acid Hybridization Test

Office Laboratory Diagnosis of Vaginitis Clinician-Performed Tests Compared with a Rapid Nucleic Acid Hybridization Test Daron G. Ferris, MD; Julie Hendrich, MD; Peter M. Payne, MD; Alan Getts, MD; Riaz Rassekh, MD; Dianne Mathis, MT; and Mark S. Litaker, MS Augusta, Georgia Uckground. The traditional diagnosis of vaginitis incor and 70.8%, respectively. The sensitivity' and specificity of porates patient symptoms, clinical findings observed the DNA probe diagnosis of the same types of vaginitis during vaginal examination, and laboratory analysis of were 75.0% and 95.7%, 86.5% and 98.5%, and 95.4% vaginal fluid. The purpose of this study was to evaluate and 60.7%, respectively. When only women with multi routine clinician-performed office laboratory diagnostic ple vaginal infections were considered, the percentages techniques for women with abnormal vaginal symp of correct clinician diagnoses for vulvovaginal candidia toms, and to compare these results with those obtained sis, vaginal trichomoniasis, and bacterial vaginosis were by a DNA hybridization test for Trichomonas vaginalis, 49.3%, 83.6%, and 59.7%, respectively. For the DNA Gardnerella vaginalis, and Candida species. probe test, the percentages of correct diagnoses were 72.9%, 92.9%, and 90.0%, respectively. Methods. The study included 501 symptomatic women ivho were between the ages of 14 and 67 years. Three Conclusions. Primary care clinicians demonstrated a high I vaginal specimens were obtained for saline wet mount, specificity' but low sensitivity when identifying vaginal potassium hydroxide (KOH) prep, amine “sniff,” pH, trichomoniasis and vulvovaginal candidiasis by microscopic and nucleic acid hybridization (T vaginalis, G vaginalis, techniques. Correct microscopic diagnosis of bacterial and Candida sp) tests. Clinicians and medical technicians vaginosis was even more difficult for clinicians, as was the independendy evaluated the wet mount, KOH prep, diagnosis of multiple vaginal infections. Clinicians were not amine, and pH tests. A medical technician processed the as accurate as the DNA probe test in diagnosing vaginal in DNA tests according to manufacturer’s protocol. fections. Clinicians need more education in the laboratory diagnosis of vaginitis. Clinicians should carefully scrutinize Results. Of 499 subjects for whom complete data were each microscopic slide, systematically examine the slide for available, vulvovaginal candidiasis was diagnosed in each type of vaginitis, and consider specimen pH and the 20.0%, vaginal trichomoniasis in 7.4%, and bacterial presence of leukocytes, Lactobacillus organisms, or amine vaginosis in 52.1%. Fourteen percent of subjects had odor as additional clues to infection. multiple vaginal infections. The sensitivity and specific ity of clinician microscopically diagnosed vulvovaginal Key words. Vaginosis, bacterial; trichomonas vaginitis; candidiasis, vaginal trichomoniasis, and bacterial vagino vulvovaginal candidiasis; DNA tests; office laboratory; sis were 39.6% and 90.4%, 75.0% and 96.6%, and 76.5% diagnostic test. ( / Fam Pract 1995; 41:575-581) The traditional clinical diagnosis of vaginal infection is and laboratory analysis of vaginal specimens. The office based on information expressed verbally by the patient, laboratory analysis of a vaginal specimen provides the clinical findings observed during the vaginal examination, most objective information. A microscopic saline wet- mount examination of the specimen permits detection of the motile protozoa Trichomonas vaginalis and of squa Submitted, revised, A ugust 21, 1995. mous epithelial cells coated by adherent bacteria known as From the Medical Effectiveness Education and Research Program (D.G.F., J.H., P.M.P., clue cells, which are one of several important criteria for A.G.), and the Departments of Family Medicine (D.G.F., J.H.), Obstetrics and Gynecol ogy (P.M.P.), the Section o f Adolescent Medicine (A.G.), and the Office of Biostatistics the diagnosis of bacterial vaginosis. A microscopic potas (M.S.L.), Medical College o f Georgia, and University Family Medicine (R.R., D.M.), sium hydroxide (KOH) examination allows recognition Augusta, Georgia. Requests fo r reprints should be addressed to Daron G. Ferris, MD, department o f Family Medicine, Medical College of Georgia, Augusta, GA 30912. of pseudohyphae and buds indicative of vulvovaginal can- §1995 Appleton & Lange ISSN 0094-3509 The Journal of Family Practice, Vol. 41, No. 6(Dec), 1995 575 Diagnosing Vaginitis Ferris, Hendrich, Payne, etal didiasis. The KOH examination also enables the amine presence of vaginitis in symptomatic women. The accu “sniff” test, which, when an odor is present, suggests the racy of a nucleic acid hybridization test designed to simul diagnosis of bacterial vaginosis. An easily performed vag taneously identify T vaginalis, Candida sp, and G vagi inal specimen pH test helps to further differentiate specific nalis in women with symptoms of vaginitis was also types of vaginitis when present. A vaginal pH less than 4.5 compared with the results from the routine office labora indicates the normal vagina or vulvovaginal candidiasis; a tory tests. pH greater than 4.5 suggests bacterial vaginosis or vaginal trichomoniasis. These tests comprise the standard for the office laboratory diagnosis of vaginitis. Methods However seemingly simple these office laboratory tests appear, the accurate diagnosis of vaginitis is subject Consenting women who were 14 years of age or older and to many variables. Patient factors, clinician and laborato- had symptoms of vaginitis were enrolled in the study at rian skill, specimen sampling, processing and interpreta five clinics in the Augusta, Georgia, area: the Family Med tion each affect the accuracy of diagnosis. Because these icine Center, Obstetrics and Gynecology Clinic, Adoles tests for vaginal infection have been recently classified as cent Medicine Clinic and Student Health Center, Medical “physician-performed microscopy” tests under the Clin College of Georgia, and the Family Planning Clinic, Rich ical Laboratory Improvement Amendments of 1988, a mond County Health Department. Symptoms of vagini new and greater diagnostic burden has been placed on tis were defined as itching, irritation, burning, an odor, many clinicians in small offices choosing to maintain a abnormal discharge, or increased vaginal discharge. The laboratory. exclusion criteria were excessive menses, recent use of Other more complex laboratory tests are available for antifungal or certain antibiotic medications (less than 2 use to diagnose vaginitis. Cultures for T vaginalis and weeks since the initiation of treatment), or douching or Candida sp are more sensitive than wet-mount examina use of non-oxynyl 9 spermicide within 24 hours of tion,1 but they are also more expensive and labor inten examination. sive, require more time for confirmation, and have limited Patients with vaginal symptoms were asked to panic routine clinical utility.2 Cultures for Gardnerella vagina- ipate in the study. Following visual examination of the Its, only one microorganism of the polymicrobial infection cervix and vagina, specimens of vaginal discharge were bacterial vaginosis, demonstrate no clinical value3 since a obtained from the lateral side walls or anterior fornix high percentage (58%) of healthy women are asymptom using three Dacron swabs. The order of swab sampling atic carriers.4 A Gram’s stain of vaginal secretions may be was consecutively alternated. Care was taken to avoid used to diagnose bacterial vaginosis and vulvovaginal can sampling cervical mucus and the posterior vaginal fornix didiasis3; however, because nonmotile trichomonads are pool so as to obtain a reliable pH determination. The first difficult to distinguish from leukocytes, the Gram’s stain is swab was placed in a test tube containing 0.2 mL of not useful for the detection of T vaginalis. The Papani normal saline for wet-mount microscopic examination. colaou (Pap) smear is able to identify all three types of The second swab was rolled across pH paper for pH vaginal infection but is limited in sensitivity.1 Further determination. The third swab was placed in the collec more, because of the potential for an obscuring inflam tion tube for DNA probe analysis. Shortly thereafter, the matory process, most clinicians actually refrain from ob tube was placed into a refrigerator set at 2°C to 8°C until taining a Pap smear when an active vaginal infection is transported to the Family Medicine Center Laboratory. clinically suspected. Tests for proline aminopeptidase,5 The clinicians independently prepared and examined a sialidases,6 and various amine and acid byproducts7-8 have portion of the first specimen for saline wet mount, KOH demonstrated value in identifying women with bacterial prep, sniff test, and pH determination. The clinician then vaginosis. Unfortunately, these tests are complex, limited indicated the appropriate diagnosis. Vulvovaginal candi to research facilities, not available to most clinicians, and diasis was defined as the presence of pseudohyphae or impractical for general clinical use.9 buds in the saline or KOH exam. Vaginal trichomoniasis Contemporary nucleic acid hybridization or DNA was defined as the presence of the motile protozoan in the probe tests are commonly used in medicine to detect a saline wet-prep examination. Bacterial vaginosis was de variety of pathogens. A rapid, easy, and accurate test to fined as the presence of clue cells on saline wet-prep ex identify

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