Medline ® Abstracts for References 44-46
of 'Bacterial vaginosis'
Reliability of diagnosing bacterial vaginosis is improved by a standardized method of gram stain interpretation.
Nugent RP, Krohn MA, Hillier SL
J Clin Microbiol. 1991;29(2):297.
The purpose of the study was to examine intercenter variability in the interpretation of Gram-stained vaginal smears from pregnant women. The intercenter reliability of individual morphotypes identified on the vaginal smear was evaluated by comparing them with those obtained at a standard center. A new scoring system that uses the most reliable morphotypes from the vaginal smear was proposed for diagnosing bacterial vaginosis. This scoring system was compared with the Spiegel criteria for diagnosing bacterial vaginosis. The scoring system (0 to 10) was described as a weighted combination of the following morphotypes: lactobacilli, Gardnerella vaginalis or bacteroides (small gram-variable rods or gram-negative rods), and curved gram-variable rods. By using the Spearman rank correlation to determine intercenter variability, gram-positive cocci had poor agreement (0.23); lactobacilli (0.65), G. vaginalis (0.69), and bacteroides (0.57) had moderate agreement; and small (0.74) and curved (0.85) gram-variable rods had good agreement. The reliability of the 0 to 10 scoring system was maximized by not using gram-positive cocci, combining G. vaginalis and bacteroides morphotypes, and weighting more heavily curved gram-variable rods. For comparison with the Spiegel criteria, a score of 7 or higher was considered indicative of bacterial vaginosis. The standardized scorehad improved intercenter reliability (r = 0.82) compared with the Spiegel criteria (r = 0.61). The standardized score also facilitates future research concerning bacterial vaginosis because it provides gradations of the disturbance of vaginal flora which may be associated with different levels of risk for pregnancy complications.
Pediatric, Adolescent, and Maternal AIDS Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Validity of the vaginal gram stain for the diagnosis of bacterial vaginosis.
Schwebke JR, Hillier SL, Sobel JD, McGregor JA, Sweet RL
Obstet Gynecol. 1996;88(4 Pt 1):573.
OBJECTIVE: To determine the sensitivity and specificity of vaginal Gram stain as interpreted by the Nugent criteria for the diagnosis of bacterial vaginosis, and to consider the use of Gram stain as the criterion standard for the diagnosis of bacterial vaginosis.
METHODS: A multicenter study was conducted of women attending gynecology or sexually transmitted disease clinics. Clinical data consisting of vaginal pH, "whiff test," clue cells, and appearance of the vaginal discharge (Amsel criteria) were compared with the vaginal fluid Gram stain (Nugent criteria) for the diagnosis of bacterial vaginosis.
RESULTS: The sensitivity and specificity of the Gram stain compared with the Amsel criteria were 89 and 83%, respectively. There was significant variation in the specificity values by geographic site. If the Gram stain was considered the criterion standard for the diagnosis of bacterial vaginosis, the sensitivity and specificity of the Amsel criteria were 70 and 94%, respectively.
CONCLUSION: The vaginal Gram stain (Nugent criteria) is a sensitive method for the diagnosis of bacterial vaginosis. The 83% specificity suggests that the currently used Amsel criteria may lead to the underdiagnosis of bacterial vaginosis.
Department of Medicine, University of Alabama at Birmingham, USA.
Gram stain method shows better sensitivity than clinical criteria for detection of bacterial vaginosis in surveillance of pregnant, low-income women in a clinical setting.
Tam MT, Yungbluth M, Myles T
Infect Dis Obstet Gynecol. 1998;6(5):204.
OBJECTIVE: The purpose of the study is to determine whether the Gram stain method is superior to the clinical criteria for the diagnosis of bacterial vaginosis in low-income pregnant women seen in a resident clinic setting. The clinical criteria is the current diagnostic method employed to diagnose bacterial vaginosis.
STUDY DESIGN: In this study, 51 pregnant women with vaginal discharge were prospectively evaluated. All were screened using the clinical criteria, Gram stain method, and culture of the discharge. The modified scoring system instituted by Nugent et al. (J Clin Microbiol 29:297-301, 1991) was employed in reading the Gram stain smears. The clinical criteria were then compared with the Gram stain method. Isolation of moderate to many Gardnerella vaginalis growth by culture was used as the confirmatory finding.
RESULTS: Sensitivity of the Gram stain method (91%) was significantly higher than that of the clinical criteria (46%), (sign test P = 0.0023,<0.01). The Gram stain method also has both a low false-negative (4%) and high negative predictive value (96%), makingit an ideal diagnostic test.
CONCLUSION: The Gram stain method is a rapid and cost-effective test that is also highly reproducible and readily available in many laboratories. These features make the Gram stain method a more desirable screening procedure for bacterial vaginosis in a clinic population.
Department of Obstetrics and Gynecology, St. Joseph Hospital, Chicago, IL, USA.