FromMedscape Infectious Diseases

Evaluation of Women With Vulvovaginal Complaints

Jeanne M. Marrazzo, MD, MPH

Authors and Disclosures

Posted: 04/19/2012

Vaginitis: It's Common

Vaginal symptoms occur frequently and prompt many women to seek healthcare. However, our ability to accurately diagnose and effectively treat vaginitis syndromes has evolved relatively little over the past decade. Almost no new antimicrobial options have emerged, and diagnostic testing options remain limited. This unfortunate scenario has fostered a situation in which affected women are generally managed on a syndromic basis. One can only hope that we are on the threshold of a new era in enhanced diagnosis and management of these all-too-common conditions.

This commentary will review key features of the 3 most common infectious causes of vulvovaginal complaints, with an eye toward emerging developments. Diagnosis is presented as a comprehensive approach to women with these complaints, but none of the infectious etiologies will explain the symptoms of many, if not most, women. A thorough history will often reveal the use of over-the-counter products including douches, external cleansing agents, cosmetics, and exposure to latex condoms or lubricants that can cause irritant or even allergic reactions.

What Makes a Healthy Vagina Healthy?

The vagina is a dynamic ecosystem that evolves over the course of a woman's lifespan, and is heavily influenced by hormones, sexual activity, and reproductive context. The vaginal pH in premenarchal women is near neutral (pH 7.0) until puberty. At puberty, under the influence of estrogen, the vaginal squamous epithelium increases in thickness, with a concomitant increase in the glycogen levels in the epithelium and vagina. The increase in glycogen supports a shift in the predominant flora to lactobacilli, and vaginal pH falls to less than 4.5. In healthy women, this low pH is maintained until menopause, when the vaginal epithelium thins, and the vaginal pH rises above 6.0.

The presence of hydrogen peroxide (H₂O₂)-producing Lactobacillus species characterizes the normal, healthy vaginal ecosystem, typically defined by a lack of symptoms and a normal pH. When present, these species -- typically L crispatus and L jensenii -- occur at very high concentrations (10 million organisms per gram of vaginal fluid). Whereas other commensal bacteria, including anaerobic gram-negative rods, streptococci, staphylococci, and diphtheroids, are relatively common in normal women, they are present at considerably lower concentrations.

Women with high vaginal concentrations of H₂O₂-producing lactobacilli are less likely to be colonized byGardnerella, genital mycoplasmas, and anaerobes, to have bacterial vaginosis (BV), and to acquire HIV and other sexually transmitted infections (STIs). Such women are more likely to have healthy pregnancy outcomes. In HIV-infected women, higher levels of vaginal lactobacilli have been associated with reduction in the quantity of HIV shed in genital secretions.^[1]

^{When Things Go Wrong: Major Causes of Vaginitis}

Vaginal symptoms such as abnormal discharge may be caused by vaginal or cervical infections, or may be associated with noninfectious processes. The most common cause of abnormal vaginal discharge is BV, followed by vulvovaginal candidiasis (VVC). Although trichomoniasis is common in some settings, particularly clinics focused on sexual health, it is the least frequent of the 3 major vaginal infections. Desquamative inflammatory vaginitis of unknown etiology is a cause of purulent vaginitis. Causes of noninfectious vaginitis include a lack of estrogen (either postpartum or after menopause), or allergic vaginitis (Table).

Table. Vaginal Syndromes and Etiologies

 

Vaginal Syndrome	Etiology
Infectious
Bacterial vaginosis	Mixed Gardnerella vaginalis, anaerobes (Prevotella, Porphyromonas, Bacteroides, Fusobacterium, Peptostreptococcus, Mobiluncus, Megasphaera, Eggerthella, Leptotrichia, members of Clostridiales order), and genital mycoplasmas
Candida vulvovaginitis	90% Candida albicans, 10% non-albicans Candida species; rarely other fungi
Trichomoniasis	Trichomonas vaginalis
Rare bacterial	Group A Streptococcus
Noninfectious
Atrophic vaginitis	Estrogen-deficient states (postmenopausal, postpartum, post-antiestrogen therapy)
Contact vulvovaginitis	Contact dermatitis (hypersensitivity)
Chemical/irritant vaginitis	Soaps, detergents, topical antimycotics
Allergic vaginitis	Allergens
Desquamative inflammatory vaginitis	Unknown (possibly bacterial or immune mechanism)
Erosive lichen planus	Immune mechanisms
Collagen-vascular diseases (systemic lupus erythematosus)	Vasculitis
Pemphigus and pemphigoid syndromes	Immune mechanisms

Bacterial Vaginosis: Epidemiology and Clinical Features

Bacterial vaginosis is probably the result of complex interactions among many species of bacteria, modified by an incompletely characterized host response. Gardnerella vaginalis was originally identified in women with BV but not in women without BV, and therefore was thought to be the causative agent. In fact, if sensitive culture or molecular amplification techniques are used, as many as 50% of asymptomatic women with normal vaginal pH and normal Gram stain of vaginal fluid are found to be colonized with G vaginalis.

Prevalence. Globally, BV is very common. Of 3739 women enrolled during 2001-2004 in a nationally representative sample of the US civilian noninstitutionalized population, almost 1 in 3 (29.2%; 95% confidence interval [CI], 27.2-31.3) had BV by Gram stain of vaginal fluid.^[2] In that study, women were more likely to have BV if they were nonwhite or reported douching, had a higher number of sex partners over their lifetime, were smokers, or reported ever having had sex with another woman. In prospective studies, BV was found in 50% or more of women who were at high risk for HIV acquisition in sub-Saharan Africa, and was estimated to be associated with a nearly 2-fold increase in risk for HIV acquisition in women.^[3]

Symptoms. Symptomatic BV, which accounts for approximately 60% of all cases, typically causes abnormal (and often increased and malodorous) vaginal discharge. The odor, usually described as "fishy," is derived from volatilization of the amines produced by the metabolism of anaerobic bacteria that characterize this disorder. The profound increase in anaerobe concentrations is associated with enhanced production of sialidase (which degrades immunoglobulin A [IgA]), glycosidase, volatile amines, and a characteristic cytokine profile. The elevation in sialidase forms the basis for a point-of-care rapid diagnostic test, the BVBLUE® (Gryphus Diagnostics, LLC; Knoxville, Tennessee).

Bacterial cultures. Conventional cultivation of bacteria from vaginal fluid of women with BV typically yields a spectrum of primarily anaerobic commensals: Gardnerella vaginalis, Prevotella species, anaerobic gram-positive cocci, Mobiluncus species, Ureaplasma urealyticum, and Mycoplasma hominis. More recently, molecular techniques that bypass cultivation requirements have been applied to greatly expand the microbiologic spectrum of BV. These techniques have detected Atopobium vaginae, Lactobacillus iners, Eggerthella, Megasphaera,Leptotrichia, Dialister, Bifidobacterium, Slackia, and bacteria related to Arthrobacter, Caulobacter andButyrivibrio. They have also detected several newly described bacteria in the Clostridiales order that are currently designated BVAB1, BVAB2, and BVAB3.

Risk factors. Critically, the initial event leading to the shift to anaerobic predominance that characterizes BV is unknown, although data suggest that sexual activity is probably a contributing factor, at least in some women. BV occurs more frequently in women who report new or higher numbers of male sex partners, is common and highly concordant among female sex partners, and rarely occurs before sexual debut, patterns that mimic the epidemiology of a typical sexually transmitted infection. Evidence supports a role for male partners in the pathogenesis of BV, because some BV-associated bacteria (including G vaginalis, A vaginae, BVAB1,andMegasphaera type 1) have been detected in the partners of women with BV, with highest quantities in coronal sulcus swab samples. Concentrations of these bacteria are low or undetectable in specimens from women without BV and from their male partners. Moreover, male condom use has been shown to be protective against BV.^[4]

High BV prevalence (27%-52%) in lesbians and concordance of BV status in female couples also support a role for sexual transmission. Sexual practices that transmit vaginal fluid between women increase BV risk. Gardner failed to causally implicate G vaginalis after inoculating it into the vagina in 13 healthy women, as only one developed BV.^[5] However, 11 of 15 women developed BV when inoculated with the vaginal fluid of women with BV, suggesting transmissible factors. The practice of receptive oral sex has also been suggested as a risk for BV or "unstable" vaginal flora. These data support roles for exogenous (sexual acquisition) factors in the initiation and/or maintenance of BV.

Management of Bacterial Vaginosis

Efforts to optimize the management of BV have been hampered by a lack of knowledge about the etiology of the initial decline of H₂O₂-producing lactobacilli that precedes the increase in vaginal anaerobes. Because the inciting event is not known, treatment of BV aims to reduce the vaginal burden of these anaerobes and ameliorate concomitant symptoms of abnormal or malodorous vaginal discharge.

Traditional pharmacologic management for episodic BV includes oral or intravaginal therapy with metronidazole or clindamycin.^[6] Both drugs are active against the anaerobes that predominate in BV, and are relatively inactive at a clinically meaningful level against the desirable Lactobacillus species. Oral and vaginal metronidazole are equally effective. With oral metronidazole given for 7 days, 83%-87% of women experience symptomatic improvement at 2-3 weeks. Improvement in vaginal symptoms occurs in 71%-78% of women who use intravaginal metronidazole regimens. Most available data support twice-daily dosing, although a regimen of once-daily dosing is used routinely and is recommended by the Centers for Disease Control and Prevention (CDC).^[6] Either clindamycin or metronidazole, given orally, is recommended for the treatment of BV throughout pregnancy.

Tinidazole, a nitroimidazole related to metronidazole, has been approved for the treatment of BV (as well as for trichomoniasis, giardiasis, and amebiasis). This drug is well absorbed, has a long half-life relative to that of metronidazole, and can be effective against metronidazole-resistant trichomoniasis. Cure rates for BV appear to be similar to those achieved by the metronidazole and clindamycin regimens.

Although short-term response to standard treatment regimens is acceptable, symptomatic BV persists or recurs in 11%-29% of women at 1 month and in 50%-70% by 3 months. Twice-weekly suppressive vaginal metronidazole (0.75% gel, used on Monday and Thursday nights) is effective in suppressing BV. The rationale for this preventive treatment is that suppression of vaginal anaerobic overgrowth may at least offer sustained relief from symptoms and increase the chances that the vaginal physiology will eventually return to normal.

Neither currently available probiotics nor vaginal acidifiers appear to be effective in maintaining a BV-free state.

Trichomoniasis

Trichomonas vaginalis is a protozoan that specifically infects the genital tract.

Epidemiology and Clinical Features

Although few nationally representative surveys have been performed, the prevalence of trichomoniasis, measured by culture of vaginal fluid, was recently reported for women in the National Health and Nutrition Examination Survey (NHANES).^[7] This survey uses a complex, stratified, multistage probability sample design with unequal probabilities of selection to obtain a nationally representative sample of the civilian noninstitutionalized population of the United States. Of more than 3754 women in the 2001-2004 NHANES who supplied a self-collected swab of vaginal secretions for T vaginalispolymerase chain reaction (PCR) assay, the prevalence was 3.1% (95% CI, 0.7%-2.3%). The prevalence was 1.3% in non-Hispanic white women, 1.8% in Mexican-American women, and 13.3% in non-Hispanic black women.

Independent risks for infection included non-Hispanic black race/ethnicity, being born in the United States, higher number of lifetime sex partners, increasing age, lower educational level, poverty, and douching. Only 15.2% of women with trichomoniasis reported vaginal symptoms.

Using PCR assay in the 12,449 participants in the National Longitudinal Study of Adolescent Health, the overall prevalence of trichomoniasis was 2.3% (95% CI, 1.8%-2.7%), a prevalence that was higher in women (2.8%), particularly black women (10.5%).^[8] Data suggest that trichomoniasis is linked with an increased risk for low birth weight. However, treatment of symptomatic trichomoniasis has not been shown to prevent preterm birth.^[9]

Most women infected with T vaginalis are asymptomatic. In symptomatic women, a change in vaginal discharge is the most common complaint. The discharge is usually purulent and yellow in color. Approximately 50% of women report abnormal odor, a result of the overgrowth of anaerobic microorganisms and consequent amine production. Vulvar itching is also reported by 50% of women with trichomoniasis. The vaginal epithelium is often erythematous. In some women, the cervix is inflamed and has punctate hemorrhages, a condition often called "strawberry cervix" (colpitis macularis). Rarely, T vaginalis has been found in the upper genital tract, but the significance of this finding is unknown.

Treatment of Trichomoniasis

Metronidazole is used widely to treat trichomoniasis. An oral dose of 2 g, which is more than 85% effective, is often used because it can be given as a single dose. Alternatively, 250 mg administered orally 3 times daily for 7 days is slightly more effective. Tinidazole, also given as a single oral dose of 2 g, has efficacy similar to metronidazole, but is more costly. With both regimens, sex partners must be simultaneously treated, and partners should abstain from sex for the week following treatment.^[6] Metronidazole-resistant strains of T vaginalishave been documented, but occur rarely. The origin of metronidazole resistance is unclear, but many of the resistant strains of T vaginalis appear to be aerotolerant. Organisms that are facultative are generally resistant to metronidazole.

Recurrent trichomoniasis is usually caused by a failure to treat all sexual partners, or by noncompliance of sexual partners with therapy. Refractory vaginal trichomoniasis, persisting after divided-dose metronidazole in excess of 7-14 g, should be treated with oral tinidazole or topical paromomycin.^[10,11] Although metronidazole has been contraindicated in pregnancy, especially during the first trimester, reviews of carcinogenicity and teratogenicity have failed to confirm the need for this precaution. Accordingly, the CDC and other experts have endorsed use of oral metronidazole for trichomoniasis therapy in all trimesters of pregnancy.^[6]

Trichomoniasis

Trichomonas vaginalis is a protozoan that specifically infects the genital tract.

Epidemiology and Clinical Features

Although few nationally representative surveys have been performed, the prevalence of trichomoniasis, measured by culture of vaginal fluid, was recently reported for women in the National Health and Nutrition Examination Survey (NHANES).^[7] This survey uses a complex, stratified, multistage probability sample design with unequal probabilities of selection to obtain a nationally representative sample of the civilian noninstitutionalized population of the United States. Of more than 3754 women in the 2001-2004 NHANES who supplied a self-collected swab of vaginal secretions for T vaginalispolymerase chain reaction (PCR) assay, the prevalence was 3.1% (95% CI, 0.7%-2.3%). The prevalence was 1.3% in non-Hispanic white women, 1.8% in Mexican-American women, and 13.3% in non-Hispanic black women.

Independent risks for infection included non-Hispanic black race/ethnicity, being born in the United States, higher number of lifetime sex partners, increasing age, lower educational level, poverty, and douching. Only 15.2% of women with trichomoniasis reported vaginal symptoms.

Using PCR assay in the 12,449 participants in the National Longitudinal Study of Adolescent Health, the overall prevalence of trichomoniasis was 2.3% (95% CI, 1.8%-2.7%), a prevalence that was higher in women (2.8%), particularly black women (10.5%).^[8] Data suggest that trichomoniasis is linked with an increased risk for low birth weight. However, treatment of symptomatic trichomoniasis has not been shown to prevent preterm birth.^[9]

Most women infected with T vaginalis are asymptomatic. In symptomatic women, a change in vaginal discharge is the most common complaint. The discharge is usually purulent and yellow in color. Approximately 50% of women report abnormal odor, a result of the overgrowth of anaerobic microorganisms and consequent amine production. Vulvar itching is also reported by 50% of women with trichomoniasis. The vaginal epithelium is often erythematous. In some women, the cervix is inflamed and has punctate hemorrhages, a condition often called "strawberry cervix" (colpitis macularis). Rarely, T vaginalis has been found in the upper genital tract, but the significance of this finding is unknown.

Treatment of Trichomoniasis

Metronidazole is used widely to treat trichomoniasis. An oral dose of 2 g, which is more than 85% effective, is often used because it can be given as a single dose. Alternatively, 250 mg administered orally 3 times daily for 7 days is slightly more effective. Tinidazole, also given as a single oral dose of 2 g, has efficacy similar to metronidazole, but is more costly. With both regimens, sex partners must be simultaneously treated, and partners should abstain from sex for the week following treatment.^[6] Metronidazole-resistant strains of T vaginalishave been documented, but occur rarely. The origin of metronidazole resistance is unclear, but many of the resistant strains of T vaginalis appear to be aerotolerant. Organisms that are facultative are generally resistant to metronidazole.

Recurrent trichomoniasis is usually caused by a failure to treat all sexual partners, or by noncompliance of sexual partners with therapy. Refractory vaginal trichomoniasis, persisting after divided-dose metronidazole in excess of 7-14 g, should be treated with oral tinidazole or topical paromomycin.^[10,11] Although metronidazole has been contraindicated in pregnancy, especially during the first trimester, reviews of carcinogenicity and teratogenicity have failed to confirm the need for this precaution. Accordingly, the CDC and other experts have endorsed use of oral metronidazole for trichomoniasis therapy in all trimesters of pregnancy.^[6]

Evaluation of Women With Vulvovaginal Complaints

A thorough evaluation of women with a complaint of vaginal discharge or odor should include the following components:

• Pelvic examination, including external genital examination, visualization of the cervix, and bimanual examination; 
• An evaluation for the clinical (Amsel) criteria of BV, including 
  • Odor of vaginal fluid (the "whiff test"). If negative, a more sensitive procedure for detecting the amines produced is performed by adding a few drops of 10% potassium hydroxide (KOH) to a few drops of vaginal fluid. The mixture should be smelled immediately ("whiffed") for the transient, "dead fish" odor characteristic of BV 
  • pH of vaginal fluid determined by narrow-range pH paper (pH 4-5.5), which may be applied to the withdrawn speculum or directly pressed against the vaginal wall with a swab 
  • Saline microscopy of vaginal fluid to look for "clue" cells (epithelial cells covered with G vaginalisand other bacteria associated with BV) and motile trichomonads diagnostic of Trichomonas vaginalis (however, a more sensitive test for this pathogen is preferred; see below) 
  • Definition of the vaginal discharge (in BV, it is homogeneous and greyish in color); and 
• Microscopy of KOH preparation to assess for yeast forms (hyphae or pseudohyphae). 

Diagnostic Testing Considerations

In addition to those described above, specific laboratory methods for diagnosing BV include:

• Oligonucleotide probes for high concentrations of G vaginalis; 
• Tests evaluating trimethylamine and pH; and 
• Detection of bacterial enzymes including proline aminopeptidase or sialidase. 

Although these tests are commercially available, the probe-based assay is part of a multiplex test that also detects Candida and Trichomonas vaginalis and must be performed in a laboratory approved to perform moderately complex testing. The rapid point-of-care tests are Clinical Laboratory Improvement Amendments (CLIA)-waived and can be performed in a few minutes. The sensitivity and specificity of these tests have varied in published studies.^[19,20]

A variety of diagnostic techniques for T vaginalis are available. With the advent of nucleic acid amplification testing (NAAT), the estimates for sensitivity of many tests is lower than previously estimated.^[21] The most commonly used and easiest technique is saline microscopy of vaginal fluid.^[22] In real-world applications, sensitivity with NAAT is as low as 44%, but most authorities consider it to be closer to 65%.^[23]

Given the low sensitivity of direct microscopic examination for detection of T vaginalis, culture, point-of-care testing using antigen detection tests, or NAAT should be considered for diagnosis of trichomoniasis in women with recurrent symptoms. Culture has a sensitivity of approximately 75% compared with NAAT, and a variety of culture media are available.A rapid point-of-care test is available commercially, which allows for the rapid detection of T vaginalis within 2-3 minutes in the clinic. Although not as sensitive as NAAT, this test has the advantage of having a sensitivity similar to culture with results available quickly enough to provide a diagnosis at the time of the visit.^[24] NAAT, either by PCR or transcription-mediated amplification (TMA), offers the most sensitive approach, and has become the gold standard in research.^[23] The TMA test is commercially available.

The Papanicolaou test may identify trichomonads, but the specificity depends on the type of test performed. Liquid-based cytology offers a highly specific approach, and results from this type of Pap test should be interpreted as valid.^[25,26]

The diagnosis of candidiasis is most often made by wet-mount microscopy of vaginal fluid. The wet-mount specimen is examined for yeasts or pseudohyphae under low-power magnification (100x), whereas subsequent high-power examination (400x) will detect the organisms. Debris from epithelial cells or mucus may be mistaken for, or may obscure, yeasts, but this problem can be eliminated by adding a few drops of 10%-15% KOH to the wet-mount specimen. The addition of KOH has been shown to improve both sensitivity and specificity. Culture is the most sensitive, routinely available diagnostic test, but should be reserved for women with refractory and recurrent vaginitis.

Vaginal Symptoms: Key Points for Clinicians

Vaginal symptoms are common in women, and lead them to seek medical care or -- more often, as first recourse -- pursue self-diagnosis and treatment. It is important for clinicians to obtain a thorough history to distinguish between acute and chronic presentations.^[27] A careful pelvic examination, measurement of vaginal pH, evaluation of vaginal odor after addition of 10% KOH, and routine microscopy are essential components of an office diagnosis. Cultures are not useful in the diagnosis of BV. Cultures are occasionally indicated for Candida vaginitis, and are vastly superior to wet mount for Trichomonas. Effective treatment options are available for these infections, but need to be tailored to identification of a specific precipitant, if possible, and to the patient's individual situation.

 

Αξιολόγηση των γυναικών Με αιδοιοκολπικός Παράπονα

Jeanne Μ. Marrazzo, MD, MPH

Συγγραφείς και Γνωστοποιήσεις

Δημοσιεύτηκε: 04/19/2012

Κολπίτιδα: Είναι κοινό

Κολπική συμπτώματα εμφανίζονται συχνά και προτρέψει πολλές γυναίκες να αναζητούν υγειονομική περίθαλψη. Ωστόσο, η ικανότητά μας για την ακριβή διάγνωση και αποτελεσματική θεραπεία κολπίτιδας σύνδρομα εξελίχθηκε σχετικά μικρό κατά την τελευταία δεκαετία. Σχεδόν καμία νέα αντιμικροβιακά επιλογές έχουν προκύψει, και διαγνωστικές δοκιμές επιλογές παραμένουν περιορισμένες. Το ατυχές αυτό το σενάριο έχει καλλιεργήσει μια κατάσταση κατά την οποία πλήττονται οι γυναίκες γενικά η διαχείριση γίνεται με βάση συνδρομική. Κάποιος μπορεί μόνο να ελπίζουμε ότι είμαστε στο κατώφλι μιας νέας εποχής στην ενισχυμένη διάγνωση και τη διαχείριση όλων αυτών των - πολύ - κοινούς όρους.

Ο σχολιασμός θα αναθεωρήσει τα βασικά χαρακτηριστικά των 3 πιο κοινές μολυσματικές αιτίες αιδοιοκολπικός καταγγελίες, με ένα μάτι προς τις αναδυόμενες εξελίξεις. Διάγνωση παρουσιάζεται ως μια ολοκληρωμένη προσέγγιση για γυναίκες με αυτές τις καταγγελίες, αλλά καμία από τις λοιμώδεις αιτίες, θα εξηγήσει τα συμπτώματα πολλών, αν όχι οι περισσότεροι, οι γυναίκες. Ένα λεπτομερές ιστορικό θα αποκαλύψει συχνά τη χρήση των over-the-counter προϊόντα, συμπεριλαμβανομένων ντουζιέρες, εξωτερικούς παράγοντες καθαρισμού, καλλυντικά, και η έκθεση στο λατέξ προφυλακτικών ή λιπαντικών που μπορεί να προκαλέσει ερεθισμό ή ακόμη και αλλεργικές αντιδράσεις.

Τι κάνει ένας υγιής Vagina υγιής;

Ο κόλπος είναι ένα δυναμικό οικοσύστημα που εξελίσσεται με την πάροδο του χρόνου ζωής μιας γυναίκας, και σε μεγάλο βαθμό επηρεάζεται από τις ορμόνες, τη σεξουαλική δραστηριότητα, και αναπαραγωγική πλαίσιο. Το pH του κόλπου σε premenarchal γυναίκες είναι κοντά στο ουδέτερο (pH 7,0) μέχρι την εφηβεία. Στην εφηβεία, υπό την επίδραση των οιστρογόνων, το πλακώδες επιθήλιο του κόλπου αυξάνει σε πάχος, με ταυτόχρονη αύξηση των επιπέδων γλυκογόνου στο επιθήλιο και του κόλπου. Η αύξηση του γλυκογόνου υποστηρίζει μια αλλαγή στις κυρίαρχες χλωρίδα να γαλακτοβάκιλλοι, και το κολπικό pH πέφτει σε λιγότερο από 4,5. Σε υγιείς γυναίκες, αυτό το χαμηλό pH διατηρείται μέχρι την εμμηνόπαυση, όταν οι κολπικοί λεπταίνει επιθήλιο, και το pH του κόλπου αυξάνεται πάνω από 6,0.

Η παρουσία του υπεροξειδίου του υδρογόνου (H ₂ O ₂ ) για την παραγωγή Lactobacillus είδη χαρακτηρίζει το φυσιολογικό, υγιές οικοσύστημα του κόλπου, που συνήθως ορίζεται από την έλλειψη των συμπτωμάτων και ένα φυσιολογικό pH. Όταν υπάρχουν, τα είδη αυτά - συνήθως crispatus L και L jensenii - συμβαίνουν σε πολύ υψηλές συγκεντρώσεις (10 εκατ. οργανισμών ανά γραμμάριο κολπικά υγρά). Ενώ άλλοι συμβιωτικών βακτηρίων, συμπεριλαμβανομένων των δραστηριοτήτων αναερόβιας gram-αρνητικά, στρεπτόκοκκων, σταφυλόκοκκων και diphtheroids, είναι σχετικά συχνές σε γυναίκες με φυσιολογικό, θα είναι παρόντες σε σημαντικά χαμηλότερες συγκεντρώσεις.

Οι γυναίκες με υψηλή κολπική συγκεντρώσεις του H  ₂  O  ₂  που παράγουν γαλακτοβάκιλλοι είναι λιγότερο πιθανό να εποικιστεί από  Gardnerella  , μυκοπλασμάτων των γεννητικών οργάνων, και αναερόβια, να έχουν το βακτηριακό vaginosis (BV), και να αποκτήσουν τον ιό HIV και άλλων σεξουαλικά μεταδιδόμενων λοιμώξεων (ΣΜΝ). Αυτές οι γυναίκες είναι πιο πιθανό να έχουν υγιή έκβαση της εγκυμοσύνης. Σε γυναίκες με HIV λοίμωξη, έχουν υψηλότερα επίπεδα του κολπικού γαλακτοβακίλλων έχουν συσχετισθεί με μείωση της ποσότητας του ιού HIV σε ρίξει εκκρίσεις των γεννητικών οργάνων. ^[1]