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VAGINOSIS AND INTERMEDIATE NUGENT SCORE
Dermendzhiev Tihomir Mishev
Chief assistant - Department of Microbiology and Immunology, Pharmaceutical faculty, Medical University, Plovdiv, Bulgaria
Hadzieva Kristina Atanasova Bozhkova Desislava Milenova Bivolarski Iliya Petrov
Assistant - Department of General and Clinical Pathology and Forensic Medicine, Medicine Faculty, Medical University, Plovdiv,
Bulgaria
ABSTRACT
Fully developed bacterial vaginosis (BV) as determined by Gram stained vaginal smears and the method of Nugent et al. with points > 7, is unambiguous and unmistakable as diagnosis. In the literature there are no data from studies on the connection between IM and the other two types of vaginoses - cytolytic vaginosis (CV) and vaginal lactobacillosis (VLB). Therefore, the behavior in these patients remains uncertain and will lead to repeating visits in the ambulatory (SOHMC). Aim: To examine the connection between cytolytic vaginosis and vaginal lactobacillosis with the status evaluated as intermediate grade in Nugent. Retrospectively were studied vaginal discharges of 2131 ambulatory patients in SOHMC. Clinical, microbiological: Gram and methylene blue staining of smears for evaluation by the score system of Nugent et al., complex quantitative and qualitative criteria and systems for the diagnosis of infectious vaginitis and vaginosis, as well as statistical methods were used. 493 (23.13%) cases of intermediate grade (IM) were found. There is no statistically significant difference between the study group (women with vaginal lactobacillosis) and the control group (without vaginal lactobacillosis) compared with the condition «intermediate grade» (a form of ABM) when using Nugent score system (p> 0.05). Between the cases with CV and intermediate grade was found a statistically significant difference with negative feedback (p <0.001). The assessment of the vaginal smear by the score system of Nugent et al. is an obligatory stage of the diagnosis of bacterial vaginosis and vaginitis. This method provides the most accurate diagnosis of bacterial vaginosis and defines the patients with normal vaginal microflora.
Keywords: vaginitis, vaginosis, intermediate Nugent score.
Vaginal microflora is a complex environment, consisting of a variety of bacterial species in different quantitative proportions [1]. Fully developed bacterial vaginosis (BV), as determined by the method of Nugent et al., points > 7, is unambiguous and unmistakable as diagnosis [1, 2]. The same is true for healthy vaginal flora dominated by normal in number and length lactobacilli (microphotographs 1 and 2). Compared with this method, the native specimen of vaginal discharge (VD) is considered to be less informative. The problem is that some forms of abnormal vaginal flora (AVF) are neither normal nor BV. In many studies the cases of AVF are evaluated as «intermediate flora» or called «intermediate- « (IM). They are included along with a fully developed BV in other types of vaginitis or as part of mixed infections [1, 3, 4, 5]. Therefore intermediate phenomenon in recent years is a subject of discussion. Some scientists consider it as a possible expression of various forms of vaginal infectious pathology - transient, partial or intermediate BV. The status "intermediate flora", according to Donders et al., is a turning point from a normal vagina to BV or BV to normal condition. In practice, however, most women interpreted in Nugent, should not have neither BV nor normal flora. From many studies reflecting the specifics of BV and intermediate group as separate categories, becomes clear that intermediate is associated with different and usually more serious set of complications compared with patients showing classical, fully expressed BV. These complications include abortion in the second trimester and other abnormalities from the normal pregnancy and giving birth [1, 6, 7]. The intermediate flora does not reply to the standard treatment for BV with metronidazole, as expected if it was partial BV. Even fully expressed BV does not always reply to the treatment. If a patient does not have lactobacilli, but has other, coccal or coccobacillar flora, «key cells» and increased vaginal pH, it does not necessarily mean that she is suffering from BV. Probably there is another disease which has
similarities with BV, but is different from it. The distinction of all these forms of AVF is the main challenge for laboratory and clinical specialist [7]. The simplified qualification system of Hay / Ison was developed on the base of a study of pregnant women and also determines the condition of the vaginal microflora as norm, and intermediate and BV [3]. Later, the system is updated by the authors by adding a fourth grade (4+), dominated only by Gram (+) coccal vaginal flora and according to some researchers criterion for aerobic vaginitis (AB), and grade 0- «the lack of bacteria» in the presence only of epithelial cells. Grade 0 describes a condition which often occurs after broad spectrum treatment for BV [8, 9]. The authors ratify this five-grade system, known as the qualification system of Ison / Hay. Compared with the criteria of Amsel [10] and the method of Nugent [11, 12] at an international study the system Ison / Hay showed excellent correlation. The method of Ison / Hay can be easily implemented in routine practice as opposed to the scoring system of Nugent, which requires careful enumeration of different types of bacteria after review of at least ten visual fields. It takes a lot of time if applied in a clinical practice. System Ison / Hay is recommended by Bacterial Special Interest Group (BSIG) as a method to be preferred for the diagnosis of BV in specialized out-hospital medical care (SOHMC) and urogenital clinics. This method is recommended in the «Guidelines for screening STI» [13]. The adopting of the uniform method of Ison / Hay in urogenital medicine clinics in the United Kingdom, according to the authors, would achieve the desired compactness in the diagnosis of BV in clinical and research activities. Both systems scores (three-grade of Hay / Ison and a five-grade of Ison / Hay) are well accepted in an international meeting as diagnostic methods for BV [13, 14, 15], but the problem with IM cases remains unsolved. In the literature there are no data from studies on the relationship between them and the other two types of vaginosis (photomicrographs 3 and 4) - cytolytic vaginosis (CV) and
vaginal lactobacillosis (VLB). Therefore, the behavior in these patients remains uncertain and will lead to repeating visits in the ambulatory (SOHMC).
Aim: To examine the relationship between cytolytic vaginosis and vaginal lactobacillosis with the status evaluated as intermediate in Nugent
Materials and methods: Retrospectively were investigated VD of 2131 patients in ambulatory SOHMC. Of these, 493 were evaluated as IM by the score system of Nugent et al. for the diagnosis of BV [2]. The research was performed in the Microbiological laboratory of the University Hospital «St. George «EAD, Plovdiv (third level of certification). Including criteria: cases assessed as intermediate- (4-6 pts.); healthy women (0-3 pts.); age over 18 years. Excluding criteria: women under age of 18; pregnant women and cases of BV. AB vaginal candidiasis, trichomoniasis and vaginal atrophy. Clinical methods: Anamnesis - subjective complaints: vaginal fluor (macroscopic characteristics); vulvovaginal pruritus; external dysuria, and internal dyspareunia. Gynecological status - inspection of vulvovaginal area and perineum; palpable
Relative number of IM cases fro
examination of organs in the pelvis; speculum examination; transvaginal ultrasound examination. Microbiological methods: Microscopic examination of the VD - stained with Gram and methylene blue smears with evaluation by: score system of Nugent et al. [2] for BV; a complex of original and supplemented microbiological criteria for CV of Cibley & Cibley [16] and vaginal lactobacilosis (VLB) by Horowitz et al. [17]. Culture examination for aerobic bacterial and fungal isolates. Adapted score system of Donders et al. [1, 18, 19] for AB, complex scores system for the diagnosis of vaginal candidiasis [18] and immunoassay test for Trichomonas vaginalis. The collected clinical and microbiological information was registered in a card collecting primary data (CCPD).
Results and discussion: In a retrospective study of VD of 2131 women, patients of gynecological ambulatories to SOHMC in Plovdiv, were found 493 cases with intermediate grade (IM). This assessment is done by the original score system of Nugent et al. [2]. Table 1 provides data on the absolute number and the level of prevalence of healthy patients and those assessed as intermediate- by Nugent et al. of all investigated women.
Table 1.
the total number of studied patients
n % Sp
IM (-) 1638 76,87% 0,91%
IM (+) 493 23,13% 0,91%
Total 2131 100,00% -
Cases of BV, AB, vaginal candidiasis, trichomoniasis and vaginal atrophy and these with normal vaginal microflora were excludes. The relative number of cases evaluated as IM of Nugent in total patient population of SOHMC is 23% [19]. Anderson M. et al. [20] found IM in 17% of their patients evaluated by
the simplified three-grade system of Hay / Ison. The study of Dermendzhiev T. [18] showed that two from five investigated women left without diagnosis, were assessed as intermediate by Nugent.
Microphotography 1. Bacterial vaginosis. Gram staining, magn. х 1000
Table 2.
Associations between cases of vaginal lactobacillosis and IM
Groups IM (-) IM (+) Total
n % Sp n % Sp n % Sp
VLB (-) 1526 93,16 0,62% 470 95,33 0,95% 1996 93,66 0,53%
VLB (+) 112 6,84 0,62% 23 4,67 0,95% 135 6,34 0,53%
Total 1638 100,00 - 493 100,00 - 2131 100,00 -
There is no statistically significant difference between the study group (women with vaginal lactobacillosis) and the control group (without vaginal lactobacillosis) compared with
the condition «intermediate score» (a form of ABM) assessed by using Nugent score (p>0.05).
Microphotography 2. Normal vaginal smear. Gram staining, magn. x 1000
Microphotography 3. Vaginal lactobacilosis. Gram staining, magn. х 1000
VLB is well differentiated clinical nosological unit and occurs as very uncomfortable, abundant white vaginal discharge and feeling of constant wetness of the underwear [17, 21]. The condition is characterized by the presence of significantly longer than the normal lactobacilli in vaginal smear. The etiology is unknown, but the distribution varies between 7-15%. VLB must
be distinguished from vaginal candidiasis, BV and CV [21]. Some authors proved a link between VLB and prior antimicrobial therapy [22]. In the literature there are no data from studies on the relationship between IM and VLB when vaginal smears are valued by the score system of Nugent et al.
Table 3.
Associations between cases with cytolytic vaginosis and intermediate grade
Groups IM (-) IM (+) Total
n % Sp n % Sp n % Sp
CV (-) 1401 85,53 0,87% 489 99,19 0,40% 1890 88,69 0,69%
CV (+) 237 14,47 0,87% 4 0,81 0,40% 241 11,31 0,69%
Total 1638 100,00 - 493 100,00 - 2131 100,00 -
In the literature there are no data from studies on the relationship between IM and CV when vaginal smears are evaluated by the score system of Nugent et al. Our study showed a statistically significant difference between cases of CV and intermediate grade by Nugent with negative feedback (p<0.001).
Only single cases of CV are assessed as IM - 4 (0.81%). This fact may be due to misinterpretation of certain lactobacillar morphtype, lack of enough experience and / or ignoring other important microbiological and pathomorphological signs indicating cytolysis of the vaginal epithelium.
Data from the study are presented in Figure 1. There are clear relationships between the groups of patients with VLB and CV and cases assessed as intermediate grade by Nugent et al. The
results confirm the understanding of many researchers that CV appears almost always in the form of monoetiological unit.
Figure 1. Associations between VLB, CV and IM in Nugent.
Conclusion: The assessment of the vaginal smear by the score system of Nugent et al. is an obligatory stage of the diagnosis of bacterial vaginosis and vaginitis. This method provides the most accurate diagnosis of bacterial vaginosis and defines the patients with normal vaginal microflora. The microbiological characteristics of vaginal lactobacillosis and cytolysis allow the method to be used simultaneously for routine diagnosis of the two conditions. Precise studies are needed on the relationship between aerobic vaginitis, vaginal candidiasis, trichomoniasis and the cases assessed as intermediate grade by Nugent et al.
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