Bacterial vaginosis

· Uncategorized
English: Bacterial vaginosis

Image via Wikip

BV

Bacterial vaginosis is the commonest cause of vaginal discharge in women.The normal Lactobacilli dominating vaginal flora is replaced with anaerobes and other organisms.There is fishy , thin and homogeneous discharge .It is usually associated with preterm births , late miscarriages , pelvic inflammatory diseases , post partum endometritis, post abortal sepsis and post hysterectomy cuff cellulitis

Discovery of bacteria in vaginal secretions.

Lactobacillus spp .in vaginal secretions was detected by Albert Doderlein in 1892.After this discovery that vaginal flora was regarded as homogeneous , consisting only of gram positive rods.Any woman having heterogeneous pattern was regarded as having non-specific vaginitis.

Gardner and Dukes in 1954 discovered Haemophilus vaginalis. Further work was carried out by him and this was renamed as Gardnerella vaginalis.In early 1980’s various anaerobic bacteria were identified in vaginal secretions.
The term bacterial vaginosis was adopted to reflect the polymicrobial alteration in vaginal flora causing an increase in vaginal pH , sometimes associated with homogeneous discharge in the absence of an inflammatory response.

Risk factors

It is very common during reproductive years.BV associated flora has been linked to various factors like,
change in sexual partners , concurrent STDs , age at the first intercourse , greater number of lifetime sex partners , cigarette smoking, use of IUCDs,
Vaginal douching has been implicated as a risk factor.
Lesbian population is having higher incidence of BV.

Microbiology

Lactobacillus plays an important role in maitaining the vaginal flora.It produces lactic acid which lowers the vaginal pH to below 4.5 and defers the growth of anaerobes and maintains the ecosystem in the vagina.
Low pH reduces the adherence of bacteria to the vaginal epithelium.
Certain lactobacilli like L orispatus and L jensenii produce hydrogen peroxide thus they reduce the chances of BV and Trichomoniasis.
Mobiluncus spp and bacteroids spp produce ketoacids , succinate in bacterial vaginosis thus reducing the killing ability of leukocytes.
This may explain why BV produces no cellular infammatory response despite of number of potentialy pathogenic micro- organisms.
Gram negative anaerobes such as bacteroides , prevotella are found in more than 50% of normal healthy women.They are strongly linked to BV.
Yeasts such as candida albicans may also present in normal healthy women.
Mycoplasma hominis , klebsiella , E coli, staph aureus can also be present.
Total bacterial count of normal flora is <10^6 organisms / ml.where as in BV counts can go upto 10^9 organisms/ml.
When there is decline in lactobacilli and increase in anaerobes it is called BV
These anaerobic organisms produce volatile amines & organic acids other than lactic acid & thus the fishy odour.
In normal pregnancy overall flora increases in vagina and lactobacili increase upto 10 fold.
With increasing gestation the flora becomes benign and dominated by the flora of low virulence.There is no threat to the foetus.Any alteration in the balance can cause threat to pregnancy itself.
We will be discussing complications of BV in pregnancy later on in this knol.

Aetiology

After so much of research , underlying pathogenesis of BV is still unclear.
In some of the studies relation between menstrual cycle and BV was demonstrated.
When oestrogen concentration is high as in follicular phase it favours the colonization of bacteria.Thus oestrogen levels may influence the development of BV. Oestrogen favours the colonization of candida and thus the infection.Large number of organisms like Mycoplasma hominis and Neisseria gonorrhoeae[1] are present in the genital tract.
This change is associated with appearance of vaginal epithelial cells with many adherent organisms , known as ‘ clue cells.’
Other theory proposes an enzymatic change in the pathogenesis of BV.
Mucinase & sialidase levels in vaginal fluid in women suffering from BV were found to be higher compared to the women with normal vaginal flora..They allow the entry of pathogens by promoting the breakdown of mucosal barrier.
Recent theory says that there is a role of phage virus in the aetiology of BV.They can coexist with bacteria and act as parasites and are capable of lysing the normal bacteria.In an analysis of the youghurt , Tao et al
found 43 different types of lactobacilli.Phages were detected in 11 of these strains, 7 of which were found to inhibit vaginal lactobacilli.
Despite so much of research , the underlying aetiology still remains unclear.

Diagnosis

It is based on the clinical features.50% women are asymptomatic.
In 50% there is increased vaginal discharge which is malodorous, fishy.
Pruritis and vulvovaginitis are uncommon

On examination

There is vaginal discharge , whitish – grey , thin , homogenous and adherent to vaginal walls with fishy smell.
Following 3 or 4 signs confirm the diagnosis
  1. Homogenous vaginal discharge
  2. Elevated pH >4.5
  3. Positive ” whiff ” test on addition of 10% KOH solution to the vaginal secretion.
  4. Positive clue cells on microscopic examination.
Vaginal pH is detected by a pH paper . Low value pH excludes BV
Whiff test has a positive predictive value of 90 % & specificity of 70%.
Clue cells are desquamated vaginal epithelial cells that are densely coated in adherent bacteria in such a manner that their borders are indistinct.
The detection of clue cell is very sensitive test for positive BV
Clue cells can be identified on gram stain or with a single drop of saline.They are pathognomic of BV
The grading of gram stained microbial flora is a cheap , simple  and objective method of diagnosing BV
Gynecologists usually do not have an instant approach to the microscope.The pH paper can be used .
whiff test is also easy to do and reliable.
Clue cells
Bacteroids
Lactobacilli
Candida


Mycoplasma hominis
Mobiluncus
Prevotella
Trichomonas
Neisseria gonorrhoeae

Obstetric complications associated with bacterial vaginosis

Preterm births (PTB)

Total number of vaginal flora increase as pregnancy advances.The concentration of anaerobes decreases while anaerobes remain constant. With advanced pregnancy flora becomes benign except–
Group B Streptococcus.There is evidence that earlier in pregnancy the BV is detected , greater the risk of PTB
Even if BV resolves spontaneously , the risk of preterm birth can not be reduced with advancing pregnancy.The mechanism by which BV can induce preterm birth is linked to ascending genital tract infection , resulting in production of inflammatory cytokines , interleukin-1 alpha , interleukin-1beta and tumour necrosis factor-alpha. They play a role in the intercellular signalling of prostaglandins.This leads to cervical ripening and uterine contractions.There is a link between increased levels of cytokines and colonisation of bacteria in the amniotic fluid.
Anticytokine antibodies are being developed to prevent the condition.
The earlier in pregnancy BV is detected , greater the risk of PTB.
The treatment of BV reduces the risk of PTB by 37-50%.

Late miscarriage

Second trimester risk is higher .

Postpartum endometritis

Risk factors are premature rupture of membranes (PROM) ,prolonged labour, increased number of vaginal examinations.
After caesarean section it develops within 2 days known as early endometritis.Bacteria go inside the cavity of uterus during operation.
Women with vaginal delivery develop late endometritis upto 6 wks post natally due to ascending infection which takes time.

Gynecological complications

Cervical intraepithelial neoplasia (CIN)

Some vaginal flora such as anaerobes associated with BV  are capable of producing carcinomatous substances like nitrosamines.
Possible role of BV in CIN is failure to control sexually transmited diseases particularly human papiloma virus HPV infection which is a risk factor for the carcinoma.

PID ( pelvic inflammatory disease )

Cervicovaginal fluids can be sucked inside the uterus and higher up during midcyclic contractions leading to PID and tubal blockage and future ectopic pregnancies.

Infertility and first trimester abortions

higher incidences of BV were found in women undergoing IVF. Vaginal flora may have an adverse effect on the sperm deposited in the vagina.Although there is no evidence.
first trimester abortions were associated with BV.
‘Clue cells’ were detected while doing the studies.

Post hysterectomy vaginal cuff cellulitis

Preoperative assesment of the vaginal flora should be done and properly treated.Women with BV have more chances of cuff infections.

Postabortal sepsis

PID following first trimester surgical abortions is due to infection with BV , N gonorrhoeae , C trachomatis.
Women having clue cells have higher incidence of the post abortal sepsis.
Preoperative treatment with clindamycin cream reduces the chances of infection.

Dysuria

Lactobacili are important in the prevention of urinary tract infections.

HIV

There is a possibility of association between BV and HIV.
Presence of hydrogen- peroxide- producing lactobacilli produce more acidic environment which is not only toxic to BV- associated flora but also to HIV.Lower vaginal pH may therefore block the production of CD4 lymphocytes whereas alkaline pH associated with BV may enhance HIV survival.
Lower vaginal pH may block the  production of CD4 lymphocytes.alkaline pH may enhance the survival of HIV .
Cohen et al demonstrated that BV is linked to increased secretion of cytokine , IL-10 which in turn increases the susceptibilty to HIV-1 infection.
Especially M hominis increase the HIV-1 expression .
HIV may promote the abnormal flora in the vagina or BV may enhance the transmission of HIV . There is strong correlation between the two.

Treatment

Drugs

  • Metronidazole
  • Clindamycin
Orally or vaginally
Clindamycin 2% cream can be applied during pregnancy.
Doses
Clindamycin 2% , 5 gms daily applied for 7 days  once daily.
In non pregnant women it can be given orally also.
Doses are 300 mgm twice daily for 7 days.
Metronidazole
orally 400 mgm twice daily for 7 days.
This has a metallic taste.
Metronidazole vaginal gel-0.75% once daily for 5 days.
It should be given prior to surgery prophylactically.

Self help

Avoidance of washing of genital area with soaps , shower gel , and other alkaline detergents.
pH balanced products are also more alkaline and should be avoided.
Douching should be discouraged.
Natural youghrt or lactobacillus acidophilus gives short term relief.
 (no doubt why Cleopetra used to have milk and curd bath)
Capsules or other products containing lactobacillus crispatus may give some relief.

Treatment of the male partners

Urethra of men may get colonised with bacteria after having relationship with woman having BV
Treatment of the male partner does not cure the disease.

Recurrence of BV

There are new episodes due to the treatment failure.
So one should be cautios.

Conclusion

BV ( Bacterial Vaginosis ) is very common and usually affects the majority of women at some point in their life.
It involves the replacement of normal lactobacilli- dominated vaginal flora with anaerobes and other organisms.
Direct microscopy of the Gram stained preparation of vaginal secretion is the ideal method for diagnosis.
It can cause malodourous discarge which is very distressing.
They can cause PTB ( Preterm births ) , HIV , post hysterectomy cuff cellulitis , PID ( pelvic inflammatory disease ) , infertility , endometritis and miscarriages.
Gynecologists and Obstetrician should be very well aware of it and should be able to diagnose the problem and treat effectively.
.

8 Comments

Comments RSS
  1. Gust MEES

    Hi,

    You will find some help about How-To with Annotum on my http://knolannotummigration.wordpress.com/. My practical experiences with Annotum in 5 minutes tutorials with a pedagogical background… easy to follow with some tips&tricks…

    Hope that this will be helpful…

    I wish You also Season’s greetings http://knolannotummigration.wordpress.com/2011/12/13/happy-holidays-seasons-greetings-merry-xmas-and-a-happy-new-year/

    BTW: good to see that your blog is featured on WordPress http://en.wordpress.com/tag/annotum/

    Have a nice day and best regards,
    Gust

  2. I was extremely pleased to discover this website. I want to to thank you for ones time just for this wonderful read!! I definitely loved every part of it and I have you book marked to check out new stuff on your blog.

  3. Greetings! Very helpful advice in this particular article! It’s the little changes that produce the greatest changes. Thanks for sharing!

  4. Hello there, There’s no doubt that your site might be having browser compatibility problems. When I take a look at your website in Safari, it looks fine however, if opening in IE, it has some overlapping issues. I merely wanted to give you a quick heads up! Besides that, fantastic site!

  5. yeast infection male

    Woah! I’m really digging the template/theme of this site. It’s simple, yet effective.

    A lot of times it’s hard to get that “perfect balance” between usability and visual appeal. I must say you’ve done a
    superb job with this. Also, the blog loads very fast for
    me on Opera. Excellent Blog!

  6. lucinda lamb

    i have been suffering with BV for over two and half years. it never goes away with treatment. it clears up only temporarily even whwn i take regular antibiotics for other problems like uti’s. ive been to several doctors and nobody can fix me. im at my wits end. im severely depressed because of it and my fiancee is starting to accuse me of cheating on him because of the smell. its ruining my life! im desperate for a cure!

    • bhagia

      With correction of ph of vagina and antifungal as well as antibiotics it will go away

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: