|Year : 1994 | Volume
| Issue : 1 | Page : 8-14
Epidemilogical and microbiological correlates of bacterial vaginosis
P Bhalla, A Kaushika
Source of Support: None, Conflict of Interest: None
Female population comprised of 544 with vaginitis and 258 asymptomatic were screened for presence of Bacterial Vaginosis (BV), Trichomonas vaginalis, Candida albicans, Gardnerella vaginalis and Mycoplasma hominis. Bacterial vaginosis, diagnosed on the basis of clinical criteria and gram's stained vaginal smear findings, was present in 50 percent of symptomatic cases and 21.8 percent of asymptomatic women. G. vaginalis, M. hominis and T. vaginalis were significantly associated with a diagnosis of BV. BV showed a positive correlation with lower socio-economic status and parity of more than 2. Prevalence of G. vaginalis was significantly higher among women who were ? 33 years of age, had been married for a shorter duration, gave history of intercourse in the preceding 48 hours and were of lower socio-economic status.
Keywords: Bacterial vaginosis, Epidemiology, G. vaginalis
|How to cite this article:|
Bhalla P, Kaushika A. Epidemilogical and microbiological correlates of bacterial vaginosis. Indian J Dermatol Venereol Leprol 1994;60:8-14
|How to cite this URL:|
Bhalla P, Kaushika A. Epidemilogical and microbiological correlates of bacterial vaginosis. Indian J Dermatol Venereol Leprol [serial online] 1994 [cited 2020 Oct 22];60:8-14. Available from: https://www.ijdvl.com/text.asp?1994/60/1/8/3972
| Introduction|| |
Bacterial vaginosis (BV) is reported to be the commonest form of vaginitis in gynaecologic outpatients and STD attenders, yet there is very little reliable data on the epidemiology of this syndrome. A major limitation in most studies on BV has been the lack of clearly defined study groups, since many investigators have not applied the diagnostic criteria put forth by Gardner and Dukes  and re-evaluated by Amsel et al . 
Mobiluncus species, Gardnerella vaginalis Mycoplasma hominis independently associated with a clinical diagnosis of BV.  Due to the close association of G, vaginalis with BV, many earlier investigators tended to rely solely on the presence or absence of this organism to diagnose BV and therefore focused on G. vaginalis associated vaginitis rather than on BV as such. Several studies have investigated the epidemiology of G. vaginalis and found an association with race, previous pregnancy, oral contraceptives and sexually transmitted diseases . ,,,
The epidemiology of BV, diagnosed on the basis of reliable clinical criteria, has been studied. ,, A significant positive correlation has been reported with increasing age, history of sexual activity, previous trichomoniasis, use of intrauterine device, other co-existant infection due to Neisseria More Details gonorrhoea, Chlamydia trachomatis and inflammatory report in wet smear.
The purpose of this study was to determine the prevalence, the microbiological and epidemiological correlates of BV among symptomatic and asymptomatic women attending the gynaecologic and Family Welfare clinics of a large city hospital.
| Materials and Methods|| |
This study was conducted from January 1988 to December 1990 and comprised of 544 women with symptoms of excessive vaginal discharge with or without pruritis and malodour and 258 asymptomatic women. Women who were menstruating or had received any treatment for vaginitis in the preceding six weeks were excluded. Detailed history was obtained from each patient about socio-economic status, present genital complaints, age, martial status, parity, stage of menstrual cycle and hours since last intercourse.
Each patient was subjected to per speculum examination to note the source, amount and type of vaginal discharge present. Women showing evidence of mucopurulent cervical discharge, cervical erythema or friability were excluded.
High vaginal swabs and cervical swabs were collected and transported to the laboratory for microscopy and culture. A bimanual per vaginum examination was done to rule out any palpable pelvic pathology.
The pH of the vaginal secretions was measured and Amine test was done using 10% KOH. 
Wet mount smear and Gram stained smear of the vaginal secretions were made and examined. Large gram positive bacilli (Lactobacillus morphotype) and small gram negative or gram variable coccobacilli (Gardnerella morphotype) were estimated semi-quantitatively according to the following scheme : 1-10/field - scanty, 10-30/field - moderate and >30/field - predominant. 
Bacterial vaginosis was diagnosed when 4 of the following 6 criteria were fulfilled. ,
a. Presence of a homogenous, thin vaginal discharge
b. Vaginal pH higher than 4.5 c. Positive Amine test d. Presence of clue cells
e. Absence or scarcity of lactobacillus morphotype and
f, Predominance of small gram negative or gram variable coccobacilli (Gardnerella morphotype).
Vaginal specimens were collected for detection of G. vaginalis, T. vaginalis and C. albicans by microscopy and culture.
Cervical specimens were obtained for detection of N. gonorrhoea and M. hominis infection.
| Culture Methods|| |
G vaginalis : Vaginal specimens were inoculated on human blood bilayer medium  and Columbia agar with 5% human blood sub and incubated at 37°C in 5-10% CO 2 for 4872 hours. Isolates that produced tiny transparent colonies with diffuse beta hemolysis, were gram negative or gram variable short rods and were oxidase and catalase negative were presumptively identified as G. vaginalis. Further tests that were put up for confirmation included hydrolysis of starch and hippurate, presence of a-glucosidase and absence of (3glucosidase. 
M hominis : Cervical specimens were transported in Mycoplasma Collection Broth, inoculated into Arginine Broth with erythromycin (AE 1°° Broth) and the pH measured daily during incubation for 11 days. Broths which showed a rise in pH were subcultured to AE100 agar that were incubated at 37°C in 5-10% CO 2 and examined after 2-4 days. Colonies of M. hominis were identified by their characteristic morphology and by inhibition of growth by specific antiserum. 
N. gonorrhoea : Cervical specimens were directly inoculated on selective chocolate agar (with VCN supplement) for culture of N. gonorrhoea. 
C. albicans : Culture for C. albicans was performed on Sabouraud's Dextrose Agar. 
T. vaginalis : Culture for T. vaginalis was performed on modified Diamond's medium. 
| Results|| |
In the present study 544 women with symptoms of vaginitis and 258 asymptomatic we men were screened for presence of BV on the basis of the well established clinical criteria  and interpretation of gram stained vaginal smear . Among cases, BV was detected in 50%, while amongst asymptomatic women BV was found in 21.8%. The prevalence of various genital pathogens associated with vaginitis including BV in the various clinical groups of patients is shown in [Table - 1]. G. vaginalis, T. vaginalis and M. hominis were found to be significantly associated with BV as compared to healthy asymptomatic controls.
[Table - 2] shows the epidemiological risk factors associated with BV. A longer duration of sexual activity as indicated by duration of marital status was significantly associated with BV (p<0.05). A lower socio-economic status and parity of more than 2 were also risk factors for development of BV (p<0.01).
Although G. vaginalis was significantly correlated with BV, the epidemiological correlates of G. vaginalis colonization were not similar to those of BV. Prevalence of G. vaginalis was significantly higher among women were less than or equal to 33 years of age and had been married for less than 6 years. G. vaginalis was recovered more frequently from women who gave a history of intercourse within the preceding 48 hours (x 2 = 3.55) and who were of lower socio-economic status (x 2sub = 3.63), but these findings were not statistically significant [Table - 3].
| Discussion|| |
The prevalence of BV varies with the population studies and the criteria employed for diagnosis. Using objective clinical criteria and interpretation of gram stained vaginal smears for the diagnosis of BV; we found a prevalence of 50% among symptomatic and 21.7% among asymptomatic women. BV was clinically diagnosed in 27.2% of symptomatic women in a study carried out in France  and in 25% of unselected consecutive females presenting at a students health centre gynaecology clinic in Washington,  half of them being asymptomatic. A similar prevalence rate has been reported even among STD attenders in Sweden.  All the above three studies employed objective criteria for the diagnosis of BV. We found a higher prevalence rate among gynaecologic outpatients possibly because all of them were sexually active married women, largely from a lower socioeconomic status.
G. vaginalis and M. hominis have been correlated with BV in several studies ,,
although the exact pathogenetic mechanisms involved are yet . unknown. In the present study also both these organisms were significantly associated with symptomatic BV.
T. vaginalis and C. albicans could be detected in only 5.5% and 6.9% of symptomatic women respectively in our study. T. vaginalis was also significantly associated with symptomatic BV. Earlier studies have also revealed a significant association between a past history of trichomoniasis and BV and 80% of women infected with T. vaginalis could be diagnosed as BV, particularly symptomatic women and women attending STD clinics. , However, since mixed vaginal infections due to T. vaginalis and BV associated microorganisms occur frequently, no etiological relationship can be derived from any statistically significant association between presence of T. vaginalis and BV.
A clinical diagnosis of BV in our study population was significantly correlated with increasing years since marriage, a lower socio-economic status and a parity of more than two but not with age, stage of menstrual cycle and hours since last intercourse. Amsel et a1  also did not find any association between BV (non-specific vaginitis) and age, stage of menstrual cycle or age at menarche, while the proportion of patients with a history of previous pregnancy, previous abortion, mean number of pregnancies and years of sexual activity were all higher among patients with nonspecific vaginitis than among normal subjects. A significant negative correlation of BV with barrier contraceptives, genital warts and vulvovaginal candidiasis has also been observed . 
The epidemilogical correlates of G. vaginalis also vary with the population studied. In an earlier study, colonization with G. vaginalis was more frequent among women with low socio-economic status, who, were non-pregnant, in the post-ovulatory stage of menstrual cycle and using nonprotective contraceptives.  In another study, logit analysis defined four factors that were significantly associated with colonization with G. vaginalis : nonwhite race, use of oral contraceptives, no history of marriage and history of pregnancy.' The prevalence of G. vaginalis is not reported to be influenced by age ,, total number of sexual partners, day of menstrual cycle or method of contraception . We found that G. vaginalis colonization was significantly associated with age (less than 33 years) and marital status (duration less than 6 years) but not with parity or stage of menstrual cycle.
| References|| |
|1.||Gardner H L, Dukes C D. Haemophilus vaginalis vaginitis. A newly defined specific infection previously classified 'non-specific' vaginitis. Am J Obstet Gynecol 1955; 69 :962. |
|2.||Amsel R, Totten PA, Spiegel CA, et al. Nonspecific vaginitis : Diagnostic Criteria and Microbial and Epidemiologic Associations. Am J Med 1983; 74: 14-22. [PUBMED] |
|3.||Hillier SL, Critchlow CW, et al. Microbiological epidemiological and clinical correlates of vaginal colonisation by Mobiluncus species. Genitourin Med 1991 ; 67 : 26-31. [PUBMED] |
|4.||McCormack WM, Hayes CH, Rosner B, et al. Vaginal colonization with Corynebacterium vaginale (Haemophilus vaginalis) J Infect Dis 1977; 136: 740-4. [PUBMED] |
|5.||Bramley HM, Dixon RA, Jones BM. Haemophilus vaginalis (Corynebacterium vaginale, Gardnerella vaginalis) in a family planning clinic population. Br J Ven Dis 1981 ; 57 : 62-6. [PUBMED] |
|6.||Thakur A, Bhalla P, Agarwal DS. Incidence of Gardnerella vaginalis in non-specific vaginitis. Ind J Med Res 1986; 83 : 567-74. |
|7.||Lefevre JC, Averous S, Bauriaud R, et al. Lower Genital Tract Infections in women Comparison of Clinical and Epidemiologic Findings with Microbiology. Sex Trans Dis 1988 ; 15 : 110-3. [PUBMED] |
|8.||Moi H. Prevalence of bacterial vaginosis and its association with genital infections, inflammation and contraceptive methods in women attending sexually transmitted disease and primary health clinics. Int J STD & AIDS, 1990 ; 1 : 86-94. [PUBMED] |
|9.||Spiegel C A, Amsel R, Holmes K K. Diagnosis of Bacterial Vaginosis by Direct Gram Stain of Vaginal fluid. J Clin Microbiol 1983; 18: 170-7. |
|10.||10 Totten PA, Amsel R, Hale J, et al. Selective Differential Human Blood Bilayer Media for Isolation of Gardnerella (Haemophilus) vaginalis. J Clin Microbiol 1982 ; 15 : 141-7. |
|11.||Piot P, Dyck E, Totten PA, er al. Identification of Gardnerella (Haemophilus) vaginalis. J Clin Microbiol 1982 ; 15 : 19-24. |
|12.||Braun P, Klein JO, Lee YH, et al. Methodologic Investigations and Prevalence of Genital Mycoplasmas in Pregnancy. J Infect Dis 1970; 121 : 391-400. [PUBMED] |
|13.||Finegold SM, Baron EJ. In : Bailey and Scott's Diagnostic Microbiology, 7th edn. London : The C V Mosby Co, 1986;868-85. |
|14.||Fouts AC, Kraus SJ. Trichomonas vaginalis. Reevaluation of its clinical presentation and laboratory diagnosis. J Infect Dis 1980 ; 141 : 137-43. [PUBMED] |
|15.||Pheifer TA, Forsyth PS, Durfee MA, et al. Nonspecific vaginitis : Role of Haemophilus vaginalis and treatment with metronidazole. N Eng J Med 1978 ; 298: 1429. [PUBMED] |
|16.||James JA, Thomason JL, Gelbart SM, et al. Is trichomoniasis often associated with bacterial vaginosis in pregnant adolescents? Am J Obstet Gynecol 1992 ; 166 : 859-63. [PUBMED] |
[Table - 1], [Table - 2], [Table - 3]
|This article has been cited by|
||Perceived reproductive morbidity and health care seeking behaviour among women in an urban slum
| ||Garg, S., Meenakshi, Singh, M.M.C., Mehra, M. |
| ||Health and Population: Perspectives and Issues. 2001; 24(4): 178-188 |
||Role of the male partner in the lower genitourinary tract infection of female
| ||Sahoo, B., Bhandari, H., Sharma, M., Malhotra, S., Sawhney, H., Kumar, B. |
| ||Indian Journal of Medical Research. 2000; 112(July): 9-14 |