Bacterial vaginosis laboratory findings: Difference between revisions

Jump to navigation Jump to search
← Older edit
VisualWikitext
Daniel Nethala (talk | contribs)
Bureaucrats, nocaptcha
4,481 edits
WikiBot (talk | contribs)
Bots, Bureaucrats, bureaucrats, interwiki, nocaptcha, Administrators
57,550 edits
m Bot: Removing from Primary care
 
(34 intermediate revisions by 5 users not shown)
Line 3: Line 3:
{{Bacterial vaginosis}}
{{Bacterial vaginosis}}


==Overview==
Bacterial vaginosis can be diagnosed by the use of clinical criteria ([[Bacterial vaginosis Amsel criteria|Amsel’s Diagnostic Criteria]]) or Gram stain. A Gram stain is considered the gold standard laboratory method for diagnosing bacteria vaginosis.<ref name=CDC_MMWR-2015>Center for Disease Control and prevention. Mortality and morbidity weekly reports. Sexually transmitted disease treatment guideline. (2015)  https://www.cdc.gov/std/tg2015/tg-2015-print.pdf Accessed on October 20, 2016</ref>
==Laboratory Findings==
==Laboratory Findings==
===Electrolyte and Biomarker Studies===
In clinical practice, the diagnosis of bacterial vaginosis is based on the presence of at least three [[Amsel criteria bacterial vaginosis|Amsel criteria]] on laboratory studies.<ref name=CDC_MMWR-2015>Center for Disease Control and prevention. Mortality and morbidity weekly reports. Sexually transmitted disease treatment guideline. (2015)  https://www.cdc.gov/std/tg2015/tg-2015-print.pdf Accessed on October 20, 2016</ref>
To find out which of these is the case, a few simple tests are done. The healthcare provider will carry out a [[Speculum (medical)|speculum]]examination and take some swabs from high in the vagina.  These swabs will be tested for:
Vaginal swabs following [[Speculum (medical)|speculum]] examination will be tested for:
* A characteristic smell—this is called the whiff test. A small amount of an alkali is added to a [[microscope slide]] that has been swabbed with the discharge—a 'fishy' odour is a positive result for bacterial vaginosis.
*Whiff test: A small amount of an alkali is added to a [[microscope slide]] that has been swabbed with the discharge—a "fishy" odor is a positive result for bacterial vaginosis.
* Loss of [[acidity]]—the vagina is normally slightly acidic (with a [[pH]] of 3.8–4.2), which helps to control bacteria. A swab of the discharge is put onto [[litmus paper]] to check the acidity. A positive result for bacterial vaginosis would be a pH of over 4.5.
*Loss of [[acidity]]: A swab of the discharge is put onto [[litmus paper]] to check the acidity. A positive result for bacterial vaginosis would be a pH>4.5 (normally slightly acidic with a [[pH]] of 3.8–4.2).
* 'Clue cells'—so called because they give a clue to the reason behind the discharge. These are [[epithelial]] cells (like skin) that are coated with bacteria. They can be seen under microscopic examination of the discharge.
*Clue cells: [[epithelial]] cells coated with bacteria (under microscopic examination of the discharge)
In research studies, the use of Nugent or Hay/Ison criteria to evaluate a Gram-stained smear of vaginal discharge is the diagnostic standard.


Two positive results in addition to the discharge itself are enough to diagnose BV. If there is no discharge, then all 3 criteria are needed.<ref name = Amsel>{{Citation | last1 = Amsel | first1 = R | last2 = Totten | first2 = PA | last3 = Spiegel | first3 = CA | last4 = Chen| first4 = KC | last5 = Eschenbach | first5 = D | last6 = Holmes| first6 = KK | year = 1983 | title = Nonspecific vaginitis. Diagnostic criteria and microbial and epidemiologic associations | journal = Am J Med | volume = 74 | pages = 14–22}}</ref>
===Gram Stain===
A Gram stain is considered the gold standard laboratory method for diagnosing bacteria vaginosis. It is used to determine the relative concentration of [[lactobacilli]] ([[Gram-positive|Gram-positive rods]]), [[Gram-negative]] and Gram-variable rods and cocci ([[Gardnerella vaginalis]], [[Prevotella]], [[Porphyromonas]], and peptostreptococci), and curved Gram- negative rods (Mobiluncus) which are characteristic of bacterial vaginosis.Gram staining is usually reserved for research studies and can be used with the Hay/Ison criteria or the Nugent criteria.<ref name=CDC_MMWR-2015>Center for Disease Control and prevention. Mortality and morbidity weekly reports. Sexually transmitted disease treatment guideline. (2015)  https://www.cdc.gov/std/tg2015/tg-2015-print.pdf Accessed on October 20, 2016</ref><ref name="pmid1706728">{{cite journal| author=Nugent RP, Krohn MA, Hillier SL| title=Reliability of diagnosing bacterial vaginosis is improved by a standardized method of gram stain interpretation. | journal=J Clin Microbiol | year= 1991 | volume= 29 | issue= 2 | pages= 297-301 | pmid=1706728 | doi= | pmc=269757 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1706728  }} </ref>


===Amsel Criteria===
====Hay/Ison Criteria====
The Hay/Ison criteria are defined as follows: <ref name="GCH2002">{{cite journal | author=Guideline Clearing House | title=2002 national guideline for the management of bacterial vaginosis | http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3032&nbr=2258 }}</ref><ref name = HayIson>{{Citation | last1 = Ison | first1 = CA | last2 = Hay | first2 = PE | year = 2002 | title = Validation of a simplified grading of Gram stained vaginal smears for use in genitourinary medicine clinics | journal = Sex Transm Infect | volume = 78 | pages = 413–415}}</ref>
{| style="border: 0px; font-size: 90%; margin: 3px;" align=center
! style="background: #4479BA; width: 175px;" | {{fontcolor|#FFF|Grading}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|Definition}}
|-
| style="padding: 5px 5px; background: #DCDCDC;" |Grade 0


In clinical practice bacterial vaginosis (BV) is diagnosed using the Amsel criteria:<ref name = Amsel>{{Citation | last1 = Amsel | first1 = R| last2 = Totten | first2 = PA | last3 = Spiegel | first3 = CA | last4 = Chen | first4 = KC | last5 = Eschenbach | first5 = D | last6 = Holmes| first6 = KK | year = 1983 | title = Nonspecific vaginitis. Diagnostic criteria and microbial and epidemiologic associations | journal = Am J Med | volume = 74 | pages = 14–22}}</ref>
| style="padding: 5px 5px; background: #F5F5F5;" | No bacteria present
|-
| style="padding: 5px 5px; background: #DCDCDC;" | Grade 1


# Thin, white, yellow, homogeneous discharge
| style="padding: 5px 5px; background: #F5F5F5;" | [[Lactobacillus]] morphotypes predominate
# [[Clue cells]] on [[microscopy]]  
|-
# [[pH]] of vaginal fluid >4.5
| style="padding: 5px 5px; background: #DCDCDC;" | Garde 2
# 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.<ref name="GCH2002">{{cite journal | author=Guideline Clearing House | title=2002 national guideline for the management of bacterial vaginosis | http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3032&nbr=2258 }}</ref>
| style="padding: 5px 5px; background: #F5F5F5;" | Mixed flora with (some [[lactobacilli]], [[gardnerella]],or mobiluncus morphotypes present)
|-
| style="padding: 5px 5px; background: #DCDCDC;" | Garde 3


An alternative is to use a Gram stained vaginal smear, with the Hay/Ison<ref name = HayIson>{{Citation | last1 = Ison | first1 = CA | last2 = Hay | first2 = PE | year = 2002 | title = Validation of a simplified grading of Gram stained vaginal smears for use in genitourinary medicine clinics | journal = Sex Transm Infect | volume = 78 | pages = 413–415}}</ref> criteria or the Nugent<ref name="Nugent1991">{{cite journal |author=Nugent, R. P., M. A. Krohn, and S. L. Hillier | title=Reliability of diagnosing bacterial vaginosis is improved by a standardized method of Gram stain interpretation | journal=J. Clin. Microbiol | year=1991 | volume=29 | pages=297&ndash;301 }}</ref> criteria. The Hay/Ison criteria are defined as follows: <ref name="GCH2002">{{cite journal | author=Guideline Clearing House | title=2002 national guideline for the management of bacterial vaginosis | http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3032&nbr=2258 }}</ref>
| style="padding: 5px 5px; background: #F5F5F5;" | Predominantly [[gardnerella]] and/or mobiluncus morphotypes (few or absent lactobacilli)
* Grade 1 (Normal): [[Lactobacillus]] morphotypes predominate.
|-
* Grade 2 (Intermediate): Mixed flora with some Lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present.
| style="padding: 5px 5px; background: #DCDCDC;" | Garde 4
* Grade 3 (Bacterial Vaginosis): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent Lactobacilli. (Hay et al., 1994)


What this technique loses in interobserver reliability, it makes up in ease and speed of use.
| style="padding: 5px 5px; background: #F5F5F5;" | Gram-positive cocci predominate
|}
 
*Grade 3 is diagnostic
 
====Nugent Criteria====
The standard for research are the Nugent Criteria.<ref name="Nugent1991">{{cite journal |author=Nugent, R. P., M. A. Krohn, and S. L. Hillier | title=Reliability of diagnosing bacterial vaginosis is improved by a standardized method of Gram stain interpretation | journal=J. Clin. Microbiol | year=1991 | volume=29 | pages=297&ndash;301 }}</ref>
 
{| style="border: 0px; font-size: 90%; margin: 3px;" align=center
|+'''Average''' per high powered (1000× oil immersion) field. View multiple fields
! style="background: #4479BA; width: 175px;" | {{fontcolor|#FFF|Score}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|0}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|1}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|2}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|3}}
! style="background: #4479BA; width: 400px;" | {{fontcolor|#FFF|4}}
|-
| style="padding: 5px 5px; background: #DCDCDC;" |[[Lactobacillus]] morphotypes
 
| style="padding: 5px 5px; background: #F5F5F5;" |>30
 
| style="padding: 5px 5px; background: #F5F5F5;" | 15-30
 
| style="padding: 5px 5px; background: #F5F5F5;" | <14
 
| style="padding: 5px 5px; background: #F5F5F5;" | <1 (this is an average)
 
| style="padding: 5px 5px; background: #F5F5F5;" | 0
|-
| style="padding: 5px 5px; background: #DCDCDC;" |[[Gardnerella]]/[[Bacteroides]] morphotypes
 
| style="padding: 5px 5px; background: #F5F5F5;" | 0
 
| style="padding: 5px 5px; background: #F5F5F5;" | <1 (this is an average)
 
| style="padding: 5px 5px; background: #F5F5F5;" | 1-4
 
| style="padding: 5px 5px; background: #F5F5F5;" | 5-30


The standard for research are the Nugent<ref name="Nugent1991">next</ref> Criteria.  In this scale a score of 0-10 is generated from combining three other scores. It is time consuming and requires trained staff but is has high [[Inter-observer reliability|interobserver reliability]]:
| style="padding: 5px 5px; background: #F5F5F5;" | >30
* 0–3 is considered negative for BV
|-
* 4–6 is considered intermediate
| style="padding: 5px 5px; background: #DCDCDC;" |Curved Gram variable rods
* 7+ is considered indicative of BV.
At least 10–20 high power (1000× oil immersion) fields are counted and an average determined.


{| class="wikitable"
| style="padding: 5px 5px; background: #F5F5F5;" | 0  
|  
Lactobacillus morphotypes — '''average''' per high powered (1000× oil immersion) field. View multiple fields.
||
[[Gardnerella]] / [[Bacteroides]] 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)
|-
|
* Score 0 for >30
* Score 1 for 15–30
* Score 2 for 14
* Score 3 for <1 (this is an average, so results can be >0, yet <1)
* Score 4 for 0
||
* Score 0 for 0
* Score 1 for <1 (this is an average, so results can be >0, yet <1)
* Score 2 for 1–4
* Score 3 for 5–30
* Score 4 for >30
||
* Score 0 for 0
* Score 1 for <5
* Score 2 for 5+
|}


A recent study <ref name="pmid17078859">{{cite journal |author=Gazi H, Degerli K, Kurt O, ''et al'' |title=Use of DNA hybridization test for diagnosing bacterial vaginosis in women with symptoms suggestive of infection |journal=APMIS |volume=114 |issue=11 |pages=784–7 |year=2006|pmid=17078859 |doi=10.1111/j.1600-0463.2006.apm_485.x}}</ref> compared the gram stain using the Nugent criteria and the DNA hybridization test Affirm VPIII in diagnosing BV.  The Affirm VPIII test detected Gardnerella in 107 (93.0%) of 115 vaginal specimens positive for BV diagnosed by gram stain.  The Affirm VPIII test has a [[sensitivity (tests)|sensitivity]] of 87.7% and [[specificity (tests)|specificity]] of 96% and may be used for the rapid diagnosis of BV in symptomatic women.
| style="padding: 5px 5px; background: #F5F5F5;" | <5


| style="padding: 5px 5px; background: #F5F5F5;" | >5


| style="padding: 5px 5px; background: #F5F5F5;" |


==References==
| style="padding: 5px 5px; background: #F5F5F5;" |
|}


{{reflist|2}}
In this scale a score of 0-10 is generated from combining three other scores. It is time consuming and requires trained staff but is has high [[Inter-observer reliability|interobserver reliability]]:
* 0–3 is considered negative for bacterial vaginosis
* 4–6 is considered intermediate
* 7+ is considered indicative of bacterial vaginosis


===Cytology===
The Papanicolaou smear is not reliable for diagnosis of bacterial vaginosis.<ref name="pmid10819823">{{cite journal| author=Greene JF, Kuehl TJ, Allen SR| title=The papanicolaou smear: inadequate screening test for bacterial vaginosis during pregnancy. | journal=Am J Obstet Gynecol | year= 2000 | volume= 182 | issue= 5 | pages= 1048-9 | pmid=10819823 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10819823  }} </ref>
===Culture===
Vaginal culture has no role in diagnosis of bacterial vaginosis. <ref name=CDC_MMWR-2015>Center for Disease Control and prevention. Mortality and morbidity weekly reports. Sexually transmitted disease treatment guideline. (2015)  https://www.cdc.gov/std/tg2015/tg-2015-print.pdf Accessed on October 20, 2016</ref><ref name="pmid27428605">{{cite journal| author=Stockdale CK| title=A Positive Culture Result for Gardnerella Is Not Diagnostic of Bacterial Vaginosis. | journal=J Low Genit Tract Dis | year= 2016 | volume= 20 | issue= 4 | pages= 281-2 | pmid=27428605 | doi=10.1097/LGT.0000000000000237 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27428605  }} </ref>


==References==
{{reflist|2}}


[[Category:Infectious disease]]
{{WH}}
{{WS}}


[[Category:Disease]]
[[Category:Disease]]
 
[[Category:Up-To-Date]]
[[Category:Gynecology]]
[[Category:Gynecology]]
[[Category:Emergency medicine]]
[[Category:Infectious disease]]

Latest revision as of 20:34, 29 July 2020

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Sexually transmitted diseases Main Page

Vaginitis Main Page

Bacterial vaginosis Microchapters

Home

Patient Information

Overview

Historical Perspective

Pathophysiology

Causes

Differentiating Bacterial vaginosis from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Amsel Criteria

History and Symptoms

Physical Examination

Laboratory Findings

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Bacterial vaginosis laboratory findings On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Bacterial vaginosis laboratory findings

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Bacterial vaginosis laboratory findings

CDC on Bacterial vaginosis laboratory findings

Bacterial vaginosis laboratory findings in the news

Blogs on Bacterial vaginosis laboratory findings

Directions to Hospitals Treating Bacterial vaginosis

Risk calculators and risk factors for Bacterial vaginosis laboratory findings

Overview

Bacterial vaginosis can be diagnosed by the use of clinical criteria (Amsel’s Diagnostic Criteria) or Gram stain. A Gram stain is considered the gold standard laboratory method for diagnosing bacteria vaginosis.[1]

Laboratory Findings

In clinical practice, the diagnosis of bacterial vaginosis is based on the presence of at least three Amsel criteria on laboratory studies.[1] Vaginal swabs following speculum examination will be tested for:

  • Whiff test: A small amount of an alkali is added to a microscope slide that has been swabbed with the discharge—a "fishy" odor is a positive result for bacterial vaginosis.
  • Loss of acidity: A swab of the discharge is put onto litmus paper to check the acidity. A positive result for bacterial vaginosis would be a pH>4.5 (normally slightly acidic with a pH of 3.8–4.2).
  • Clue cells: epithelial cells coated with bacteria (under microscopic examination of the discharge)

In research studies, the use of Nugent or Hay/Ison criteria to evaluate a Gram-stained smear of vaginal discharge is the diagnostic standard.

Gram Stain

A Gram stain is considered the gold standard laboratory method for diagnosing bacteria vaginosis. It is used to determine the relative concentration of lactobacilli (Gram-positive rods), Gram-negative and Gram-variable rods and cocci (Gardnerella vaginalis, Prevotella, Porphyromonas, and peptostreptococci), and curved Gram- negative rods (Mobiluncus) which are characteristic of bacterial vaginosis.Gram staining is usually reserved for research studies and can be used with the Hay/Ison criteria or the Nugent criteria.[1][2]

Hay/Ison Criteria

The Hay/Ison criteria are defined as follows: [3][4]

Grading Definition
Grade 0 No bacteria present
Grade 1 Lactobacillus morphotypes predominate
Garde 2 Mixed flora with (some lactobacilli, gardnerella,or mobiluncus morphotypes present)
Garde 3 Predominantly gardnerella and/or mobiluncus morphotypes (few or absent lactobacilli)
Garde 4 Gram-positive cocci predominate
  • Grade 3 is diagnostic

Nugent Criteria

The standard for research are the Nugent Criteria.[5]

Average per high powered (1000× oil immersion) field. View multiple fields
Score 0 1 2 3 4
Lactobacillus morphotypes >30 15-30 <14 <1 (this is an average) 0
Gardnerella/Bacteroides morphotypes 0 <1 (this is an average) 1-4 5-30 >30
Curved Gram variable rods 0 <5 >5

In this scale a score of 0-10 is generated from combining three other scores. It is time consuming and requires trained staff but is has high interobserver reliability:

  • 0–3 is considered negative for bacterial vaginosis
  • 4–6 is considered intermediate
  • 7+ is considered indicative of bacterial vaginosis

Cytology

The Papanicolaou smear is not reliable for diagnosis of bacterial vaginosis.[6]

Culture

Vaginal culture has no role in diagnosis of bacterial vaginosis. [1][7]

References

  1. ↑ 1.0 1.1 1.2 1.3 Center for Disease Control and prevention. Mortality and morbidity weekly reports. Sexually transmitted disease treatment guideline. (2015) https://www.cdc.gov/std/tg2015/tg-2015-print.pdf Accessed on October 20, 2016
  2. ↑ 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.
  3. ↑ Guideline Clearing House. "2002 national guideline for the management of bacterial vaginosis". Unknown parameter |http://www.guideline.gov/summary/summary.aspx?ss= ignored (help)
  4. ↑ 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: 413–415
  5. ↑ Nugent, R. P., M. A. Krohn, and S. L. Hillier (1991). "Reliability of diagnosing bacterial vaginosis is improved by a standardized method of Gram stain interpretation". J. Clin. Microbiol. 29: 297&ndash, 301.
  6. ↑ Greene JF, Kuehl TJ, Allen SR (2000). "The papanicolaou smear: inadequate screening test for bacterial vaginosis during pregnancy". Am J Obstet Gynecol. 182 (5): 1048–9. PMID 10819823.
  7. ↑ Stockdale CK (2016). "A Positive Culture Result for Gardnerella Is Not Diagnostic of Bacterial Vaginosis". J Low Genit Tract Dis. 20 (4): 281–2. doi:10.1097/LGT.0000000000000237. PMID 27428605.

Template:WH Template:WS

Retrieved from "https://www.wikidoc.org/index.php?title=Bacterial_vaginosis_laboratory_findings&oldid=1635076"