|Classification and external resources|
|Specialty||Gynecology, infectious disease|
|Patient UK||Bacterial vaginosis|
Bacterial vaginosis (BV), also known as vaginal bacteriosis or Gardnerella vaginitis, is a disease of the vagina caused by excessive bacteria. Common symptoms include increased vaginal discharge that often smells like fish. The discharge is usually white or gray in color. Burning with urination may occur. Itching is uncommon. Occasionally there may be no symptoms. Having BV increases the risk of infection by a number of other sexually transmitted infections including HIV/AIDS. It also increases the risk of early delivery among pregnant women.
BV is caused by an imbalance of the naturally occurring bacteria in the vagina. There is a change in the most common type of bacteria and a hundred to thousandfold increase in total numbers of bacteria present. Risk factors include douching, new or multiple sex partners, antibiotics, and using an intrauterine device among others. However, it is not considered a sexually transmitted infection. Diagnosis is suspected based on the symptoms and may be verified by testing the vaginal discharge and finding a higher than normal vaginal pH and large numbers of bacteria. BV is often confused with a vaginal yeast infection or infection with Trichomonas.
Usually treatment is with an antibiotic, such as clindamycin or metronidazole. These medications may also be used in the second or third trimesters of pregnancy. However, the condition often recurs following treatment. Probiotics may help prevent re-occurrence. It is unclear if the use of probiotics or antibiotics affects pregnancy outcomes.
BV is the most common vaginal infection in women of reproductive age. The percentage of women affected at any given time varies between 5% and 70%. BV is most common in parts of Africa and least common in Asia and Europe. In the United States about 30% of women between the ages of 14 and 49 are affected. Rates vary considerably between ethnic groups within a country. While BV like symptoms have been described for much of recorded history, the first clearly documented case occurred in 1894.
Signs and symptoms
Common symptoms include increased vaginal discharge that usually smells like fish. The discharge is often white or gray in color. There may be burning with urination. Occasionally there may be no symptoms.
The discharge coats the walls of the vagina, and is usually without significant irritation, pain, or erythema (redness), although mild itching can sometimes occur. By contrast, the normal vaginal discharge will vary in consistency and amount throughout the menstrual cycle and is at its clearest at ovulation—about 2 weeks before the period starts. Some practitioners claim that BV can be asymptomatic in almost half of affected women, though others argue that this is often a misdiagnosis.
Healthy vaginal microbiota consists of species which do not cause symptoms, infections, or negatively affect pregnancy. It is dominated mainly by Lactobacillus species. BV is defined by the disequilibrium in the vaginal microbiota with decline in the number of lactobacilli. While the infection involves a number of bacteria, it is believed that most infections start with Gardnerella vaginalis creating a biofilm which allows other opportunistic bacteria to thrive.
One of the main risks for developing BV is douching, which alters the vaginal flora and predisposes women to developing BV. Douching is strongly discouraged by the U.S. Department of Health and Human Services and various medical authorities, for this and other reasons.
BV is a risk factor for pelvic inflammatory disease, HIV, sexually transmitted infections (STIs), and reproductive and obstetric disorders or negative outcomes. It is possible for sexually inactive persons to develop bacterial vaginosis.
Bacterial vaginosis may sometimes affect women after menopause. Subclinical iron deficiency may correlate with bacterial vaginosis in early pregnancy. A longitudinal study published in February 2006 in the American Journal of Obstetrics and Gynecology showed a link between psychosocial stress and bacterial vaginosis persisted even when other risk factors were taken into account. Exposure to the spermicide nonoxynol-9 does not affect the risk of developing bacterial vaginosis.
Having a female partner increases the risk of BV by 60%. The bacteria associated with BV have been isolated from male genitalia. BV microbiota have been found in the penis, coronal sulcus, and male urethra, in the male partners of infected females. Those uncircumcised partners may act as a ‘reservoir’ increasing the likelihood of acquiring an infection after sexual intercourse. Another mode of transmission of BV associated microbiota is to a female sexual partner via the skin-to-skin transfer. BV may be transmitted via the perineal enteric bacteria from the microbiota of the female and male genitalia.
To make a diagnosis of bacterial vaginosis, a swab from inside the vagina should be obtained. These swabs should be tested for:
- A characteristic "fishy" odor on wet mount. This test, called the whiff test, is performed by adding a small amount of potassium hydroxide to a microscopic slide containing the vaginal discharge. A characteristic fishy odor is considered a positive whiff test and is suggestive of bacterial vaginosis.
- Loss of acidity. To control bacterial growth, the vagina is normally slightly acidic with a pH of 3.8–4.2. A swab of the discharge is put onto litmus paper to check its acidity. A pH greater than 4.5 is considered alkaline and is suggestive of bacterial vaginosis.
- The presence of clue cells on wet mount. Similar to the whiff test, the test for clue cells is performed by placing a drop of sodium chloride solution on a slide containing vaginal discharge. If present, clue cells can be visualized under a microscope. They are so-named because they give a clue to the reason behind the discharge. These are epithelial cells that are coated with bacteria.
Two positive results in addition to the discharge itself are enough to diagnose BV. If there is no discharge, then all three criteria are needed.[non-primary source needed] Differential diagnosis for bacterial vaginosis includes the following:
- Normal vaginal discharge.
- Candidiasis (thrush, or a yeast infection).
- Trichomoniasis, an infection caused by Trichomonas vaginalis.
The Center For Disease Control (CDC) defines STIs as "a variety of clinical syndromes and infections caused by pathogens that can be acquired and transmitted through sexual activity." But the CDC does not specifically identify BV as sexually transmitted infection.
In clinical practice BV can be diagnosed using the Amsel criteria:
- Thin, white, yellow, homogeneous discharge
- Clue cells on microscopy
- pH of vaginal fluid >4.5
- Release of a fishy odor on adding alkali—10% potassium hydroxide (KOH) solution.
At least three of the four criteria should be present for a confirmed diagnosis. A modification of the Amsel criteria accepts the presence of two instead of three factors, and is considered equally diagnostic.
- Grade 1 (Normal): Lactobacillus morphotypes predominate.
- Grade 2 (Intermediate): Mixed flora with some Lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present.
- Grade 3 (Bacterial Vaginosis): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent Lactobacilli. (Hay et al., 1994)
Gardnerella vaginalis is the main culprit in BV. Gardnerella vaginalis is a short rod (coccobacillus). Hence, the presence of clue cells and gram variable coccobacilli are indicative or diagnostic of bacterial vaginosis.
The standards for research are the Nugent criteria. In this scale, a score of 0-10 is generated from combining three other scores. This method is time consuming and requires trained staff, but it has high interobserver reliability. The scores are as follows:
- 0–3 is considered negative for BV
- 4–6 is considered intermediate
- 7+ is considered indicative of BV.
At least 10–20 high power (1000× oil immersion) fields are counted and an average determined.
Lactobacillus morphotypes — average per high powered (1000× oil immersion) field. View multiple fields.
Curved Gram variable rods — average per high powered (1000× oil immersion) field. View multiple fields (note that this factor is less important — scores of only 0–2 are possible)
DNA hybridization testing with Affirm VPIII was compared to the Gram stain using the Nugent criteria. The Affirm VPIII test may be used for the rapid diagnosis of BV in symptomatic women but uses expensive proprietary equipment to read results, and does not detect other pathogens that cause BV, including Prevotella spp, Bacteroides spp, & Mobiluncus spp.
One review concluded that probiotics may help prevent re-occurrence. Another review found that while there is tentative evidence it is not strong enough to recommend their use for this purpose.
Antibiotic treatment of male partners could re-establish the normal microbiota of the male uro-genital tract. BV associated bacteria in or on the male genitals may promote relapse, reinfection of, women with BV. Treating the male partner is an effective and safe intervention and offers the advantage of preventing the recurrence of infection.
Treatment is typically with the antibiotics metronidazole or clindamycin. They can be either given by mouth or applied inside the vagina. About 10% to 15% of people; however, do not improve with the first course of antibiotics and recurrence rates of up to 80% have been documented. Recurrence rates are increased with sexual activity with the same pre-/posttreatment partner and inconsistent condom use although estrogen-containing contraceptives decrease recurrence. When clindamycin is given to pregnant women symptomatic with BV before 22 weeks of gestation the risk of pre-term birth before 37 weeks of gestation is lower.
Other antibiotics that may work include macrolides, lincosamides, nitroimidazoles, and penicillins.
A 2009 Cochrane review found tentative but insufficient evidence for probiotics as a treatment for BV. A 2014 review reached the same conclusion. A 2013 review found some evidence supporting the use of probiotics during pregnancy.
Although previously considered a mere nuisance infection, untreated bacterial vaginosis may cause complications, such as increased susceptibility to sexually transmitted infections including HIV and pregnancy complications.
It has been shown that HIV-infected women with bacterial vaginosis (BV) have higher HIV concentrations in their vaginal secretions. Diagnostic criteria for BV have also been associated with a female genital tract factor that induces expression of HIV. The elevated HIV copy number in vaginal secretions of women with BV has been associated with an increased risk of heterosexual transmission of HIV.
There is evidence of an association between BV and increased rates of sexually transmitted infections such as HIV/AIDS. BV is associated with up to a six-fold increase of HIV shedding. There is also a correlation between the absence of vaginal lactobacilli and infection of Neisseria gonorrhoeae and Chlamydia trachomatis. BV is a risk factor for viral shedding and herpes virus type 2 infection. BV may increase the risk infection or reactivation of HPV.
In addition, bacterial vaginosis an intercurrent disease in pregnancy may increase the risk of pregnancy complications, most notably premature birth or miscarriage. Pregnant women with BV have a higher risk of chorioamnionitis, miscarriage, preterm birth, premature rupture of membranes, and postpartum endometritis. BV is associated with gynaecological and obstetric complications. Data suggest an association between BV, tubal factor infertility, and pelvic inflammatory disease. Women with BV who are treated with vitro fertilization have a lower implantation rate and higher rates of early pregnancy loss.
BV is the most common infection of the vagina in women of reproductive age. The percentage of women affected at any given time vary between 5% and 70%. BV is most common in parts of Africa and least common in Asia and Europe. In the United States about 30% of those between the ages of 14 and 49 are affected. Rates vary considerably between ethnic groups within a country.
- Borchardt, Kenneth A. (1997). Sexually transmitted diseases : epidemiology, pathology, diagnosis, and treatment. Boca Raton [u.a.]: CRC Press. p. 4. ISBN 9780849394768.
- Donders, GG; Zodzika, J; Rezeberga, D (April 2014). "Treatment of bacterial vaginosis: what we have and what we miss.". Expert opinion on pharmacotherapy 15 (5): 645–57. doi:10.1517/14656566.2014.881800. PMID 24579850.
- Clark, Natalie; Tal, Reshef; Sharma, Harsha; Segars, James (2014). "Microbiota and Pelvic Inflammatory Disease". Seminars in Reproductive Medicine 32 (01): 043–049. doi:10.1055/s-0033-1361822. ISSN 1526-8004.
- "What are the symptoms of bacterial vaginosis?". http://www.nichd.nih.gov/. 2013-05-21. Retrieved 3 March 2015.
- Kenyon, C; Colebunders, R; Crucitti, T (December 2013). "The global epidemiology of bacterial vaginosis: a systematic review.". American journal of obstetrics and gynecology 209 (6): 505–23. doi:10.1016/j.ajog.2013.05.006. PMID 23659989.
- Queena, John T. .; Spong, Catherine Y; Lockwood, Charles J., editors (2012). Queenan's management of high-risk pregnancy : an evidence-based approach (6th ed.). Chichester, West Sussex: Wiley-Blackwell. p. 262. ISBN 9780470655764.
- "What are the treatments for bacterial vaginosis (BV)?". http://www.nichd.nih.gov/. 2013-07-15. Retrieved 4 March 2015.
- "Bacterial Vaginosis (BV): Condition Information". http://www.nichd.nih.gov/. 2013-05-21. Retrieved 3 March 2015.
- "Bacterial Vaginosis – CDC Fact Sheet". Centers for Disease Control and Prevention. March 11, 2014. Retrieved 2 Mar 2015.
- Mashburn, J (2006). "Etiology, diagnosis, and management of vaginitis.". Journal of midwifery & women's health 51 (6): 423–30. doi:10.1016/j.jmwh.2006.07.005. PMID 17081932.
- Othman, M; Neilson, JP; Alfirevic, Z (24 January 2007). "Probiotics for preventing preterm labour.". The Cochrane database of systematic reviews (1): CD005941. PMID 17253567.
- "Bacterial Vaginosis (BV) Statistics Prevalence". cdc.gov. September 14, 2010. Retrieved 3 March 2015.
- Schwebke JR (2000). "Asymptomatic bacterial vaginosis: response to therapy". Am. J. Obstet. Gynecol. 183 (6): 1434–9. doi:10.1067/mob.2000.107735. PMID 11120507.
- Forney LJ, Foster JA, Ledger W (2006). "The vaginal flora of healthy women is not always dominated by Lactobacillus species". Journal of Infections Diseases 194 (10): 1468–9. doi:10.1086/508497. PMID 17054080.
- Petrova, Mariya I.; Lievens, Elke; Malik, Shweta; Imholz, Nicole; Lebeer, Sarah (2015). "Lactobacillus species as biomarkers and agents that can promote various aspects of vaginal health". Frontiers in Physiology 6. doi:10.3389/fphys.2015.00081. ISSN 1664-042X.
- Patterson, J. L.; Stull-Lane, A.; Girerd, P. H.; Jefferson, K. K. (12 November 2009). "Analysis of adherence, biofilm formation and cytotoxicity suggests a greater virulence potential of Gardnerella vaginalis relative to other bacterial-vaginosis-associated anaerobes". Microbiology 156 (2): 392–399. doi:10.1099/mic.0.034280-0.
- Cottrell BH (2010). "An Updated Review of Evidence to Discourage Douching". MCN, the American Journal of Maternal/Child Nursing 35 (2): 102–107; quiz 107–9. doi:10.1097/NMC.0b013e3181cae9da. PMID 20215951.
- Verstraelen H, Delanghe J, Roelens K, Blot S, Claeys G, Temmerman M (2005). "Subclinical iron deficiency is a strong predictor of bacterial vaginosis in early pregnancy". BMC Infect. Dis. 5 (1): 55. doi:10.1186/1471-2334-5-55. PMC 1199597. PMID 16000177.
- Nansel TR, Riggs MA, Yu KF, Andrews WW, Schwebke JR, Klebanoff MA (February 2006). "The association of psychosocial stress and bacterial vaginosis in a longitudinal cohort". Am. J. Obstet. Gynecol. 194 (2): 381–6. doi:10.1016/j.ajog.2005.07.047. PMC 2367104. PMID 16458633.
- Wilkinson, D; Ramjee, G; Tholandi, M; Rutherford, G (2002). "Nonoxynol-9 for preventing vaginal acquisition of sexually transmitted infections by women from men.". The Cochrane database of systematic reviews (4): CD003939. PMID 12519623.
- Amaya-Guio, Jairo; Martinez-Velasquez, Mercy Yolima; Viveros-Carreño, David Andres; Sierra-Barrios, Eloisa Mercedes; Grillo-Ardila, Carlos F; Amaya-Guio, Jairo (2015). "Antibiotic treatment for the sexual partners of women with bacterial vaginosis". doi:10.1002/14651858.CD011701.
- Amsel R, Totten PA, Spiegel CA, Chen KC, Eschenbach D, Holmes KK (1983). "Nonspecific vaginitis. Diagnostic criteria and microbial and epidemiologic associations". Am. J. Med. 74 (1): 14–22. doi:10.1016/0002-9343(83)91112-9. PMID 6600371.
- "Diseases Characterized by Vaginal Discharge". cdc.gov. Centers for Disease Control and Prevention.
- Workowski, Kimberly A. and Bolan, Gail A. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep 2015; volume 64, issue 3:p.1.
- "National guideline for the management of bacterial vaginosis (2006)". Clinical Effectiveness Group, British Association for Sexual Health and HIV (BASHH).
- Ison CA, Hay PE (2002). "Validation of a simplified grading of Gram stained vaginal smears for use in genitourinary medicine clinics". Sex Transm Infect 78 (6): 413–5. doi:10.1136/sti.78.6.413. PMC 1758337. PMID 12473800.
- Nugent RP, Krohn MA, Hillier SL (1991). "Reliability of diagnosing bacterial vaginosis is improved by a standardized method of gram stain interpretation". J. Clin. Microbiol. 29 (2): 297–301. PMC 269757. PMID 1706728.
- Gazi H, Degerli K, Kurt O, Teker A, Uyar Y, Caglar H, Kurutepe S, Surucuoglu S (2006). "Use of DNA hybridization test for diagnosing bacterial vaginosis in women with symptoms suggestive of infection". APMIS 114 (11): 784–7. doi:10.1111/j.1600-0463.2006.apm_485.x. PMID 17078859.
- "Bacterial Vaginosis – CDC Fact Sheet". Centers for Disease Control and Prevention. March 11, 2014. Retrieved 6 May 2015.
- Mastromarino, Paola; Vitali, Beatrice; Mosca, Luciana (2013). "Bacterial vaginosis: a review on clinical trials with probiotics" (PDF). New Microbiologica 36: 229–238. PMID 23912864.
- Oduyebo OO, Anorlu RI, Ogunsola FT (2009). Oduyebo, Oyinlola O, ed. "The effects of antimicrobial therapy on bacterial vaginosis in non-pregnant women". Cochrane Database Syst Rev (3): CD006055. doi:10.1002/14651858.CD006055.pub2. PMID 19588379.
- Senok, Abiola C; Verstraelen, Hans; Temmerman, Marleen; Botta, Giuseppe A; Senok, Abiola C (2009). "Probiotics for the treatment of bacterial vaginosis". doi:10.1002/14651858.CD006289.pub2. PMID 19821358.
- Bradshaw CS, Vodstrcil LA, Hocking JS, Law M, Pirotta M, Garland SM, De Guingand D, Morton AN, Fairley CK (Mar 2013). "Recurrence of bacterial vaginosis is significantly associated with posttreatment sexual activities and hormonal contraceptive use.". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 56 (6): 777–86. doi:10.1093/cid/cis1030. PMID 23243173.
- Lamont, Ronald F.; Nhan-Chang, Chia-Ling; Sobel, Jack D.; Workowski, Kimberly; Conde-Agudelo, Agustin; Romero, Roberto (2011). "Treatment of abnormal vaginal flora in early pregnancy with clindamycin for the prevention of spontaneous preterm birth: a systematic review and metaanalysis". American Journal of Obstetrics and Gynecology 205 (3): 177–190. doi:10.1016/j.ajog.2011.03.047. ISSN 0002-9378. PMID 22071048.
- Mehta SD (October 2012). "Systematic review of randomized trials of treatment of male sexual partners for improved bacteria vaginosis outcomes in women". Sex Transm Dis 39 (10): 822–30. doi:10.1097/OLQ.0b013e3182631d89. PMID 23007709.
- Potter J (November 1999). "Should sexual partners of women with bacterial vaginosis receive treatment?". Br J Gen Pract 49 (448): 913–8. PMC 1313567. PMID 10818662.
- Senok, AC; Verstraelen, H; Temmerman, M; Botta, GA (7 October 2009). "Probiotics for the treatment of bacterial vaginosis.". The Cochrane database of systematic reviews (4): CD006289. PMID 19821358.
- Huang, H; Song, L; Zhao, W (June 2014). "Effects of probiotics for the treatment of bacterial vaginosis in adult women: a meta-analysis of randomized clinical trials.". Archives of gynecology and obstetrics 289 (6): 1225–34. PMID 24318276.
- VandeVusse, L; Hanson, L; Safdar, N (2013). "Perinatal outcomes of prenatal probiotic and prebiotic administration: an integrative review.". The Journal of perinatal & neonatal nursing 27 (4): 288–301; quiz E1–2. PMID 24164813.
- "STD Facts — Bacterial Vaginosis (BV)". CDC. Archived from the original on 3 December 2007. Retrieved 4 December 2007.
- J Acquir Immune Defic Syndr 39 (3): 340–6. Jul 2005. Missing or empty
- PLoS Med 9 (6): e1001251. 2012. doi:10.1371/journal.pmed.1001251. Missing or empty
- Bacterial vaginosis from National Health Service, UK. Page last reviewed: 03/10/2013