17: vaginal secretions

the risk of preterm delivery is assessed by detecting the enzyme ________

fetal fibronectin

the placental ________ protein and insulin-like growth factor binding ________ are detected to diagnose ruptured fetal membranes

α₁-microglobulin; protein-1

what are the three purposes for analyzing vaginal secretions?

• diagnose infections

• complications of pregnancy

• forensic testing in sexual assault

what are the symptoms of vaginitis?

• abnormal discharge

• odor

• vaginal irritation

• dysuria

• dyspareunia

vaginitis is secondary to what conditions?

• bacterial vaginosis

• vulvovaginal candidiasis

• trichomoniasis

• noninfectious conditions

what are the three main tests for vaginitis?

• saline wet mount

• KOH exam

• gram stain

what other tests may be used when analyzing vaginal secretions?

• litmus pH level

• DNA probe testing

• culture

• point of care test kits

what is used to collect vaginal secretions?

sterile, polyester-tipped swabs on plastic shaft

vaginal secretions are swabbed in a tube containing ________ to ________ mL of ________ and agitated

0.5; 1.0; sterile physiologic saline

specimens must be kept at what temperature to preserve the motility of which organisms?

room temperature; Trichomonas vaginalis and N. gonorrhoeae

which organisms must be refrigerated to prevent overgrowth of normal flora?

C. trachomatis and HSV

T. vaginalis specimens must be examined how long after specimen collection?

within 2 hours

what is the normal appearance and consistency of vaginal secretions?

white with flocculent discharge

what organisms are predominantly seen microscopically?

large, rod-shaped, gram-positive lactobacilli

what normal cells may be seen microscopically?

squamous epithelial cells, potential WBCs, RBCs if the patient is menstruating

what appearance and consistency are typical of discharge in bacterial vaginosis?

thin, homogenous white-to-gray discharge

what appearance and consistency are typical of discharge in candida infections?

white “cottage cheese”-like discharge

what appearance and consistency are typical of discharge in trichomonas vaginalis?

yellow-green, frothy, adherent discharge

what color and consistency are typical of discharge in chlamydia trachomatis?

yellow, opaque cervical discharge

what is the normal vaginal pH range?

3.8-4.5

pH is increased in what conditions?

bacterial vaginosis, trichomoniasis, desquamative inflammatory vaginitis, atrophic vaginitis

what organism is responsible for maintaining vaginal pH?

lactobacilli

what do lactobacilli produce to maintain pH?

lactic acid

for a KOH/wet mount, cells/organisms are quantified under which objective?

40x

with gram stain, cells/organisms are reported at which objective?

100x

how large are epithelial cells in diameter?

25 to 70 micrometers

what shape are epithelial cells?

polygonal “flagstone” with prominent, centrally located nucleus

what are clue cells?

squamous epithelial cells covered in clusters of bacteria

clue cells are diagnostic of which type of bacterial vaginosis?

gardnerella vaginalis

which cells are described as “shaggy?”

clue cells

how large are WBCs?

14 to 16 micrometers in diameter

what are PMNs?

polymorphonuclear white blood cells

>3+ WBCs is suggestive of which conditions?

• vaginal cadidiasis

• atrophic vaginitis

• infections with trichomonas, chlamydia, neisseria, gonorrhoeae, or herpes simplex

how large are RBCs?

7 to 8 micrometers

RBCs usually appear in vaginal secretions in what conditions?

menstruation, desquamative inflammatory process

KOH helps distinguish which cells?

RBCs (lysed) from yeast

the vagina has complex ________ bacterial flora

endogenous

Lactobacillus spp are large, gram-________, nonmotile ________, which produce lactic acid

positive; rods

what microorganisms are part of the vaginal flora?

• aaerobic streptococci

• diptheroids

• coagulase-negative staphylococci

• A-hemolytic streptococci

alterations in normal flora can cause overgrowth of ________ flora

opportunistic

trichomonas vaginalis are atrial ________ protozoan

flagellated

trichomonas vaginalis have ________ anterior flagella and an ________ membrane that extends half the length of the body

four; undulating

trichomonas vaginalis flagella tend to have which motion?

“jerky”

nonmotile trichomonads can be mistaken for which cells?

WBCs

trichomonads lose motility after how long?

2 hours

trichomonads can only be reported if ________ is observed

motility

candidiasis is caused by which organisms?

candida albicans and non-Candida spp.

which occasional yeast are considered part of the normal flora?

budding yeast (blastophores), hyphae, and pseudophyphae

differentiation of yeast can be made using which test?

KOH

how is KOH test performed?

placing a drop of saline vaginal specimen and one drop of 10% KOH solution on a clean slide

what indicates a positive amine (“whiff”) test?

presence of fishy odor

what indicates a negative amine (“whiff”) test?

absence of fishy odor

a positive amine test indicates what condition?

bacterial vaginosis (gardnerella vaginalis in conjunction with mobiluncus spp. and with trichomonas vaginalis)

what additional testing is used to confirm bacterial vaginosis?

gram stain, specimen culture, DNA probe testing, POCT

what is the gold standard in identifying the causative organisms for BV?

gram stain

gram stain for BV involves weighted combination of which morphotypes?

lactobacillus acidophilus, gardnerella vaginalis and bacteroids spp., and mobiluncus spp.

lactobacillus acidophilus are gram-________, ________-shaped bacteria

positive; rod

gardnerella vaginalis and bacteroids spp. are gram-________ or gram-________, ________-shaped bacteria

variable; negative; rod

mobiluncus spp. are gram-________, curved ________-shaped bacteria

variable; rods

what is the nugent score for normal vaginal flora?

0 to 3

what is the nugent score for intermediate?

4 to 6

what nugent score is diagnostic of bacterial vaginosis?

>7

what is the leading cause of neonatal mortality and morbidity in the united states?

preterm delivery

what is the adhesive glycoprotein in the extracellular matrix at the maternal and fetal interface in the uterus?

fFN (fetal fibronectin)

fFN is elevated the first ________ weeks of pregnancy, then diminishes

24

fFN in vaginal secretions 24-34 weeks of gestation indicates what?

preterm delivery

what are symptoms of preterm delivery?

• change in vaginal secretions

• vaginal bleeding

• uterine contractions

• abdominal or back discomfort

• pelvic pressure

• cramping

specimens for fetal fibronectin testing are obtained by rotating a swab across the posterior fornix or the vagina for ________ seconds

10

what are the methods for detection of fFN enzyme immunoassay?

• solid-phase enzyme-linked immunosorbent assay (ELISA) or lateral flow

• solid-phase immunochromatographic assay=Rapid fFN cassette

rapid fFN assay is a ________ test, with results reported as

qualitative; positive or negative

symptomatic pregnant women with positive fFN are at increased risk of delivery within 7-14 days from specimen collection

asymptomatic pregnant women with positive fFN are at increased risk for delivery in <= 34 weeks and 6 days of gestation